AudioCircle
Other Stuff => Archived Manufacturer Circles => Ellis Audio => Topic started by: TomW16 on 11 Aug 2005, 03:18 pm
-
Hi Dave,
I have been lurking here for years patiently waiting for the Ellis 3-Way to materialize and from what I understand there could be 2 different speakers in the works:
i) existing 1801b speaker retrofitted with a 10" woofer, which would be backwards compatible for existing 1801b customers should they choose to add the woofer.
ii) new 3-way speaker with OW1F tweeter, W18EX001 mid and potentially a TC Sounds 12" woofer.
There has not been too much action on these topics in the last little bit so I thought I would create this thread to help me (and others) understand the status of both speakers. This would also help me determine the time frame that I have to save up the required money and purchase the kit. :D
I hope that you are doing well and that your hectic life is manageable and fun.
Thanks.
Tom
-
Inquiring minds want to know...
:D
-
Hi Dave,
In case my original e-mail was too subtle, I was hoping to obtain the status of both 3-way speakers from you. I.e., time lines to kit launch, prices, etc. I wanted to clarify just in case you were thinking that I was going to update the group with the status. :lol:
Take care,
Tom
-
I have "valid" woofers for the 10" speaker, but it remains behind the following projects.
1. Craig Dorval's 1801 speakers.
2. A deck on my home.
3. Wiring in the basement.
I haven't heard from TC sounds for about 45days regarding the 12" woofer, but during our last chat I told them not to rush. I did some testing with an Accuton driver (C95). The performance was surprisingly good. The Accuton's better cone, better motor airflow, and tight tolerances might "trump" the SEAS shorting rings and phase plug. Some testing with an Accuton midrange will follow if the Accuton C95 proves better than the W18.
However, I am not sure if this will work. The Accuton might not be sensitive enough. I figured out how to use Neo magnets in the W18EX to get another 1.5db sensitivity. Another possibility is a custom driver from Accuton or SEAS. This would be expensive.
After limited time with the Accuton C95... my CLIO measurement jig got a bit whacky. I still haven't completely solved this.
I have learned of a reputable gent that refoams drivers http://layneaudio.hypermart.net/repair.htm . Given this knowledge, the TC sounds driver might have a foam surround. Everyone agrees that foam is better. It is better damped and lighter than rubber, but it needs to be replaced every 10-20 years.
Dave
-
This would also help me determine the time frame that I have to save up the required money and purchase the kit.
I really don't know which one will get done first. I am more excited about the 12" woofer 3-way. Dynamics performance IS directly related to sensitivity. If the TC woofer gets finished relatively soon, this project will happen first.
Dave
-
Thanks for the status update Dave. I am leaning towards the 12" woofer 3-way at this point (due to the perceived/potential better soncs) so if you finish that one first, all the better for me. Take your time as I need to save up my pennies.
I'll be watching this thread to learn about the speakers' status periodically.
Take care,
Tom
-
Dave, you said:
everyones agrees that foam is better damped and lighter than rubber...but it needs to be replaced every 10-20 years.
IMHO, it exists some thin rubber surround that approachs the weight of a foam equivalent; Scan-Speak uses such stuff on their drivers, particularly on their "revelator" series. Furthermore :idea: it could also be used some dampening varnish that doesn't dry with time; well known speakers in France "Apertura" (Christian Yvon) uses successfully such varnish on their custom "Davis" drivers.
In addition, I'm not sure that foam surround on such 12"woofer does better perform than rubber on frequencies less than 200-300hz. If we look at the drivers market, foam is used almost only on high sensitive midranges with high fs.
And...intellectually and subjectively, I would hesitate to buy a speaker with a driver surround that I know it will have to be replaced even in a few years. For my cheap car stereo yes, for a 2000 dollars speaker kit pair not.
:beer:
-
If we look at the drivers market, foam is used almost only on high sensitive midranges with high fs.
Why do you think this is?
IMHO, it exists some thin rubber surround that approachs the weight of a foam equivalent; Scan-Speak uses such stuff on their drivers, particularly on their "revelator" series.
There are huge variations among the rubber used in surrounds and their thickness. Given the same weight, a foam surround will be better damped than rubber.
The better foams seem to last about 10 years. Some report 20 years, and folks in humid/salty environments might only get 5-7 years from their surround.
I'll make a few statements of belief here. These statements are based on input from very knowledgable industry folks. I welcome anyone of any degree of authority on the matter to disagree.
1. Foam is better damped than rubber.
2. Foam is lighter than rubber given the same general application.
3. There are only 2 downsides to foam.
a. It will eventually have to be replaced (at @10 years)
b. It's less durable than rubber for abrasion
Summary,
The only valid reason to use a rubber surround is durability.
When attepting to obtain the very highest level of sonic performance, foam surrounds are better.
There is one potential "hole" in these comments. Some folks may WANT a heavier surround and subsequently a heavier cone. This will indeed lower the Fs of the driver. My response to this is that if more weight is desired, it should be added to the moving assembly it should be added to the cone. A heavier cone can & should have greater strength/dampening.
And...intellectually and subjectively, I would hesitate to buy a speaker with a driver surround that I know it will have to be replaced even in a few years. For my cheap car stereo yes, for a 2000 dollars speaker kit pair not.
Yes, this is an upside-down issue. You'd think that for $2k the speaker would also be more durable too. Unfortunately, the best surround will require about $100 of maintenance every 10 years. I am indeed concerned about this, but ONLY from a marketing perspective. I'll use whatever sounds the best.
An analogy... Consider the 2000 BMW M5 built with nice lightweight forged pistons. The have a very low silicon content and expand considerably in the cylinder when warm. This is the downside to a really great set of forged pistons. Their very light weight necessiates this construction method. The result is these cars typically burn a quart of oil every 1000 miles. Performance comes with a cost. When the highest performance is desired, even the best materials have compromises.
I'm not sure that foam surround on such 12"woofer does better perform than rubber on frequencies less than 200-300hz.
This is VERY valid. The other option is fabric. Testing will be done.
The difference is that foam will weigh less and provide higher sensitivity.
Moving mass is very critical. Saving 10grams of mass in a 12" woofer might net 1-2 db of sensitivity. Commonly this is done with a thin paper cone, but for me this won't happen. Such cones do flex. This is not acceptable.
I DO apprecaite you input and commentary. I AM "on the fence" regarding a foam surround. I AM concerned about folks being able to obtain a quality replacement foam surround in 10 years (me included).
As with last significant endeavor (the 1801), my intent is to build what I want. If other folks want to buy it - okay. It's all in God's will. I feel blessed in this hobby.
Personally, I often wonder if building speakers is the "right" thing for me to do with my spare time. There are many thoughts, but these are primary...
1. It's a very healthy hobby (and cheaper than golf) :)
2. God does have a plan :)
Sincerely,
-
Dave,
Hubert saidwhen we look at the drivers market, foam is used almost on high sensitive midranges with high fs
IMO, the present "high end hifi" bass-midranges and woofers, at least from the wellknown european manufacturers, use at 90% natural or synthetic rubbers; foam is more often used on cheaper series of woofers or on real cones-midranges/uppermids(i.e. Audax PR series) or on a few tweeters(i.e. Focal inversed dome). But I admit not to know the entire drivers market.
I guess that a "standard designed surround" builded with foam, rubber or whateverelse cannot damp the great energy at relative low frequencies transmitted by a woofers cone; IMO, to really damp the waves, once had to place a large amount of dampening material in woofers surround...but the moving mass would increase...; In fact, the real matter of surround is more on elastical proprietaries allowing to get a good phase relationship with the moving parts i.e. mecanical stiffness of the oscillant system, and other issues that I cannot translate in good english but that you know.
I am not a drivers engineer, I only know the physical laws of waves propagation and dampening and what I guess is only...what I guess in a theorical matter. If testings will proof the superiority of the foam surround on your woofer, I will understand the fact that you will use it in your 3 way. :D
:beer:
-
I can see the market trends too. Foam is visible on cheaper dirvers, but completely absent in hifi drive units currently produced. The only place foam is visible is some higher end pro-sound units. This is really quite strange, but I can totally understand the mindset. Folks really do expect their $10000 speakers to last a lifetime without any maintenance.
If a little foam makes things a little better, I'll use it. I am not interested in building a suboptimal speaker. I am interested in building the best speaker possible. This will be expensive, and it might have long-term maintenance costs (i.e. foam replacement). I fully realize my orientation in this matter might yield less than ideal marketing. But, I am not interested in marketing. I am interested in... the best set of compromises oriented toward sound quality.
If (IF) I use foam, I suspect there will be a littany of questions regarding this choice. In this regard, I have also continuously answered the following questions BEFORE folks purchase the 1801:
1. Can a metal 7" driver really produce good midrange when used with a 3/4" tweeter.
2. Can a metal 7" driver really produce enough bass for me?
3. Can a small 2-way speaker really push enough sound pressure for my room?
AFTER their 1801 project, nobody asks these questions :) Very positive customer feedback is my reward for going slightly against the grain.
-
Dave,
OK, I understood your point of view about the surrounds problem and about the goal of your 3 way.
I am interested in building the best speaker possible
I learned that present permanent/standard manufactured magnets are worse than those made in past. They would lose partly their magnetic field (until 50%, even alnico!!!) relatively quickly (in a few years) and consequently the technical parameters of the driver are very affected.
May I know your thoughts/knowledges about this matter and how you will manage it in your future "best speaker possible"? :wink:
Thanks,
:beer:
-
Neodymium has a very poor heat tolerance, but creates a very good and permanent magnetic field.
I haven't read "hear-say" about drivers loosing that much magnetic field, but do believe they lose some magnetic field. I have some W18 drivers in my personal speakers made about 4 years ago. They still measure the same. Maybe there are different grades of ferrous magnets, but the companies I will use are reputable folks. I believe they would use the good ferrous magnets.
I thought (?) Alnico was a very permanent magnet.
My summary on this matter is...
1. There is a very solid technical basis for magnet degradation.
2. I surely haven't measured any decline of my ferrous magnets. Further, making the entire speaker from Neo magnet drivers is not possible at this time. Each driver would have to be custom made. The tweeter would be most expensive. Oskar said a new design tweeter would cost @$30k+ depending on what I wanted. SEAS makes a Neo midrange, but the sensitivity is too low. The woofer cost increase would be minor.
3. Since I cannot make the entire speaker from Neo drivers, it makes more sense to make the entire speaker from Ferrous magnet drivers. This way, the slow decline in magnet power will be more uniform.
Dave
-
Hello Dave,
some testings with an Accuton midrange will follow if the C95 prooves better than the W18... not sure it will work, it may not be sensitive enough.
The killer :guns: seems to be here:
http://www.clofis.nl/nl/thiel/C90-T6.pdf
However, it is very...expensive:
In Europe:
C95-T6: 259€
C90-T6: 459€
:beer:
-
I probably should have extrapolated further. ..
I am not sure if 88.5db will be sensitive enough. Many of the Accuton drivers are about 88.5db sensivite. The Accuton C79 is what I was thinking of for a midrange.
But... yes, the new Accuton would appear to be "the deal", but VERY expensive.
Dave
-
Dave,
I have been following closely with your 3-way speaker design. I visited Dennis Murphy once to audition 1801 bookshelf, prototype 1801 MTM floor stand, and saw a somewhat trapzoid-like cabinet with a large woofer a couple years ago. I like 1801 much, but would love to have a full range floor stand for my next speaker upgrade. After listening to 1801, I am obviously much interested in your next invention!
Regarding your 3-way, is there a upper cap you would like to keep? What interests me the most are the diamond tweeters from Accuton and they seems to be quite popular among a few high-end speaker makers. Forget about price point for a moment; have you had a chance to audition the diamond tweeters?
Being a Class A high current amp user, 88.5db seems reasonable to me. I can see that you like make the new speaker be more sensitive (, likely 90+ db), but how about the impedence curve that you have in mind? Some good speakers I have heard have a difficult 2 ohm load at some frequency ranges, which may be a difficult drive for many amps. I am just wondering what your are trying to shoot for. If a high sensitivity and easy 8 ohms are the design goal, perhaps low watt amps are of better choice for its 'unique' magic! Just curious!!
-
Regarding your 3-way, is there a upper cap you would like to keep?
... Not really but it'll be something that I am willing to spend my own $$ for. I heard the Accuton Diamond tweeter in 2002 ( I don't remember the speaker). It sounded good, but... not that good. I really didn't think it sounded better than the other great tweeters. This is my opinion, and certainly others are welcome to disagree. I would not spend $ on this tweeter for my own living room, and this tweeter is not a possbility from my workshop. There are many other great tweeters. The Accuton C12, C23, Dynaudio Esotar, Raven R1, Scanspeak Revelator come to mind immediately.
but how about the impedence curve that you have in mind?
It will dip no lower than 6 ohms dcr and have @8 ohms nominal. Another goal is to make the impedance VERY flat so the amplifier will have a less reflective load. This can be accomplished in the crossover, and will probably cost @$150 per pair of speakers.
What you mention about impedance and sensitivity can be VERY deceiving. This is because MOST speakers are rated based on volts (i.e. spl/2.83v) for their sensitivity ratings. However, most amplifiers ratings are stated in watts. This discussion can get very long, but I'll offer the following simple example:
... a small rant....
A 90db speaker at 2 ohms, a 87db speaker at 4 ohms and a 84db speaker at 8 ohms will all draw the same current from an amplifier. This current draw from the amplifer (ANY AMPLIFIER) is the source of heat and thermal compression within that amplifier. Some folks are quick to recite hear-say concerning tube amplfiers and their problems with current load, but the same is true with solid state amplifiers.
Some reading of the AKSA site and Rod Elliots projects, easily reveal that higher power supply rail votage can be used in these amplifiers but only if the load will be 8 ohms nominal (6+ ohms dcr minimum). Using the higher voltage in their @60watt amplifiers will allow these amplifiers to push @100 watts. The sad truth is these amplifiers are DESIGNED for a 4 ohm minimal load and higher current capacity. This limits their output to 60 watts. Obtaining 100 watts from those same general components in the same general configuration would require the designer to approximately double the amplifier component count.
I believe it's common for folks to desire a very minimal speaker crossover, but sadly uncommon for folks to desire a very minimal amplifier design. Sure, there is a good crowd of SET folks, but these folks seem quite isolated from the masses in hifi.
My belief is, "The most effective amplifier for a given speaker is an amplifier designed for the impedance load of that speaker".
If a high sensitivity and easy 8 ohms are the design goal, perhaps low watt amps are of better choice for its 'unique' magic! Just curious!!
Given my statement above, this should be fairly clear. I am aiming for 90-93db at a very flat 8 ohms nominal impedance with a low dcr of 6 ohms. The dcr will likely land around 6.2 ohms.
The speaker in Dennis's living room does indeed sound very good, but the impedance is @4 ohms due to the crossover. Given a flat baffle and the desire for correct phase, this low impdeance appears unavoidable. However, with a slanted baffle (backward leaning) there is mechanical phase adjustment. The electrical focus of the crossover can be oriented toward a higher impedance.
If a high sensitivity and easy 8 ohms are the design goal, perhaps low watt amps are of better choice for its 'unique' magic! Just curious!!
Yes... and a couple thoughts....
1. One of the reasons for my orientation towards higher sensitivity is an experience I had a few years ago. I think this is mentioned elsewhere, but I'll mention it again.
I listened to a Tannoy Churchill on a single 300b tube amp. It sounded good - very good. There was something present in this setup that I never heard previously. Some distortion was distinctly absent. The dynamics were very good. Sure, there was some cone flex. Sure, the highs weren't perfect. Sure, the bass wasn't powerful. But, the midrange dynamics were very nice. I attribute this to very low current (and low thermal compression) in the amplifer and in the speaker.
2. Given the X-max potential of the drivers I'll use, this speaker could really pack a wallop with @100+ wpc amp. However, it'll most likely sound the best with a lower power SET amp @15watts. Maybe a dual 300b amp? I'll certainly provide some input but believe my customers will provide the subjective dissertation on this matter.
Oh, I should also add that the limitation of sensitivty in this speaker (and any speaker) is the size of the cabinet. This speaker will be BIG, but will not grow larger than 5 cubic feet.
Dave
-
Hi Dave.
Your (very informative) post alluded to several things that I've been wondering about, and I'm hoping that you can provide some additional clarification...
Another goal is to make the impedance VERY flat so the amplifier will have a less reflective load.
Did you mean reflective, or reactive? (Or are they interchangable?)
Ok, first a few statements to clarify my own mind...
1) Impedance is a combination of resistive (real component) and reactive (imaginary component) contributions
2) The reactance of a component varies with frequency
3) Resistive loads are easier for an amplifier to drive
4) Signal reflections occur when two components have mis-matched impedances (with an acoustical result generally described as "smearing" of the sound)
5) Variations in a speaker's impedance curve mean that mis-matches with the amp will almost certainly occur at particular frequencies - even if the amp is well matched to the nominal impedance of the speaker
Assuming that I have all of that correct, what I was trying to isolate from your statement above was whether a flat impedence curve necessarily means the speaker is primarily a resistive load and therefore easier to drive and a "bumpy" impedance curve means that a speaker is more reactive in nature and therefore harder to drive? I realize that impedance peaks at particular frequencies indicate regions of increased reactance, but I wasn't sure what you could assume about the overall ratio of resistive to reactive. In otherwords, could the impedence curve be perfectly flat, but still dominated by the reactive contribution?
You made several other comments that seemed to connect impedance, current draw, and a speaker's abilities to handle dynamics, but I don't think I quite connected all of the dots - can you clarify? Is it as simple as reduced current demand = less thermal compression = better dynamics? If so, I still need the connection to impedance...
Thanks for any pointers!
-
Some reading of the AKSA site and Rod Elliots projects, easily reveal that higher power supply rail votage can be used in these amplifiers but only if the load will be 8 ohms nominal (6+ ohms dcr minimum). Using the higher voltage in their @60watt amplifiers will allow these amplifiers to push @100 watts. The sad truth is these amplifiers are DESIGNED for a 4 ohm minimal load and higher current capacity. This limits their output to 60 watts. Obtaining 100 watts from those same general components in the same general configuration would require the designer to approximately double the amplifier component count.
David,
Without a long and boring discussion of power amp design, this is indeed largely true. The AKSA and Rod's amp were both designed for 4R loads, because this is the safest option commercially. There are so many 4R speakers out there that you'd be risking everything if the amp performed only with 8R loads. In that scenario, it would be risking instability or even outright destruction with 4R loads.
Designing for 100W should account also for 4R, in fact a little lower, perhaps 3R. To avoid approaching the SOAR limits of the output devices, you'd need to double the output stage size to two pairs rather than one. Larger speakers often use more drivers than small speakers, and this usually lowers their impedance still further. I've been embarassed with one manufacturer deliberately connecting his large 2.5R speaker to one of my 55W AKSAs. It didn't sound effortless, so he then demoed one of his own amps to the customer - who'd originally intended to build an AKSA - and won the sale. This sort of dirty trick is common in high fi, in fact, life in general.
AKSAs have been built which are stable down to 1.62R loads. They use four output pairs!! But the call for such a powerful amplifier is very limited, and so I've taken the decision to offer only the 55W and the 100W versions.
Cheers,
Hugh
-
Thanks for the confirmation Hugh.
I've been embarassed with one manufacturer deliberately connecting his large 2.5R speaker to one of my 55W AKSAs.
Yes, this is a dirty trick. Much of this is clouded for customers, and the "safe" bet for amplifier manufacturers is hedging towards amplifier construction that will accomodate lower impedance loads. However, as you illustrate, this approach is sub-optimal.
Dave
-
David-
Will you be benchmarking (or probably already have) other DIY 3-way designs. Rick Craig's designs come to mind. Comments here?
thx
Jim
-
Will you be benchmarking (or probably already have) other DIY 3-way designs.
What do you mean by "benchmarking"?
Dave
-
I mean listening to and comparing the competition to what you intend to design. 'Typically' business requires understanding the competition in order to design a new product and understand how this new product fits into the existing market.
That is unless someone designs a product differently (or their business intentions are different)...e.g for a speaker, to sound the best to them for a certain price point or....etc..you get the idea.
I know you had to recently re-look at your business model and I am curious on the strategy to expand the product line.
Thx
Jim
-
Yep, this is what I thought you meant, but I wanted to be sure.
Yes, this will happen, but you will never hear my comments about the comparisons. I have always and will always leave ALL comments concerning subjective comparison's to other folks :) . I will occasionally venture into more objective criteria regarding loudspeaker driver units and such, but this is the limit of my marketing rhetoric. Please indluge a small rant for a moment...
IMO, there are way too many folks who sell a "no compromise" loudspeaker. I'll make a statement of fact herein: These folks are stupid, or believe their listeners are stupid. After some education about loudspeakers I have learned there are copious compromises - a varitable plethora of possibilities. Yikes, the decisions are endless. Yet, there are many folks selling a "no compromise product". Such products have the ability to produce exquisite detail and a liquid midrange that puts YOU in the 10th row at the symphony. This is obviously hogwash. I chose to avoid this completely.
//
Some comparisons have already happened. I feel some degree of comfort conveying that about 2 years ago Dennis Murphy already compared a prototype Ellis 3-way that compared... prefferably to to the other high-end DIY speakers available at this time. This crowd did not include John K's NAO, but did include the 2 other superb loudspeakers available. We did not proceed because the impedance was 4 ohms and I wanted to work with this issue myself. I will NOT convey specifically what 2 other speaker's were used for comparison. I will convey that Dennis's preference was only slightly in favor of the Ellis e-way.
I must admit the only other likely comparison with a 3-way that will happen when I finish is with Jim Salk's 3-way. This is simply a matter of convenience. I also believe that Jim's 3-way speaker represents @ the best product available at any price. I will also get this speaker reviewed before several well-eared local folks before release. // Another small rant...
I believe there are several fundamental mistakes "earned" in commercial hifi.
1. Quality control and component consistency are poor.
2. Crossover development is minimal.
3. Changes in component (drivers primarily) do NOT result in crossover design changes.
There are many more issues, but I think these 3 are very critical. I also understand these 3 are VERY expensive with regard to labor cost.
-
There are many other great tweeters. The Accuton C12, C23, Dynaudio Esotar, Raven R1, Scanspeak Revelator come to mind immediately.
My current speaker uses Dyn Esotar T330. I personally like it much. In term of treble frequency, do you find the 'newer' tweeters that extend into 40Khz or above to warrant 'sensable' improvements over the traditional tweeters that extend only to about 20-25Khz range.
The sad truth is these amplifiers are DESIGNED for a 4 ohm minimal load and higher current capacity. This limits their output to 60 watts. Obtaining 100 watts from those same general components in the same general configuration would require the designer to approximately double the amplifier component count.
I believe it's common for folks to desire a very minimal speaker crossover, but sadly uncommon for folks to desire a very minimal amplifier design.
Perhaps this is why many higher end amps while still output 200W, but due to its high current desing, it weights 100-150lbs. While the component counts increase, it also demands better matching for the parts and hence contradicts the purose of minimal amp design.
While I am still a novice in basic amp design concepts, but I do learn from experience that 'more' properly built amps (often heavy and expensive, too) while output the same watt, it is capable of rendering an open and relax 3-D soundstage with much ease than the others. This type of difference is even much more noticable for musicphiles who are into large scale orchestral work. My impression is that more 'headroom' an (high-current) amp has, better transient, dynamic, stable/robust soudstage, flow of music an amp can convery. Obviously if a pair of more 'efficient' speakers are used, these strengths may not be as apparent; in contrast, a pair of efficient speakers may often reveal the flaws of amp due to the electrical noise generated by the large amount of component parts used.
As you siad, "The most effective amplifier for a given speaker is an amplifier designed for the impedance load of that speaker." May be that's also why many friends of mine have multiple pairs of speakers paired with various brands of (dedicated) amps. However, for ordinary people like us, a dedicated and specially selected amp for a given pair of speaker is great as long as ones are not bitten by the upgrade bugs. :) Since this is meant-to-be the ultimate 3-way speaker, that is truly the least of the concerns. :wink:
This speaker will be BIG, but will not grow larger than 5 cubic feet.
Is there any preliminary speculation of the dimension yet? How big of a room is this 3-way speaker designed to perform in?
Thanks.
-
Repeated Post --- deleted
-
My current speaker uses Dyn Esotar T330.
This is a very good tweeter. The only thing that might be supererior are the newer underhung Accuton tweeters (I haven't heard them yet) and the Accuton Diamond tweeter. However, I suspect that while some other tweeters might be better than the Dyn Esotar, you should NOT spend the $$ to replace your Dyn Esotar tweeters. Arguably, these tweeters will be "among the best" for many years to come.
do you find the 'newer' tweeters that extend into 40Khz or above to warrant 'sensable' improvements over the traditional tweeters that extend only to about 20-25Khz range.
No, and I don't think this extended response has any significant impact. There is some valid argument viable for aluminum dome teeters at higher hz, but I really don't hear the problem. Further, most folks physical hearing drops-off around 17khz. They can't hear anything above 20khz. I think the primary reason for the extended response among some tweeters is marketing. I am a bit more practical regarding my opinion of tweeter sound quality. I'd rather comment subjectively about what I can hear than what I cannot hear. Those extended response tweeters obviously fall into the latter category.
While I am still a novice in basic amp design concepts, but I do learn from experience that 'more' properly built amps (often heavy and expensive, too) while output the same watt, it is capable of rendering an open and relax 3-D soundstage with much ease than the others.
Yep, I have heard this too. However, can you explain why the 200wpc amp sounds better than the 35wpc push pull when the peak consumption is 30 watts? I believe the answer lies in the ability for an amplifier to push a GOOD 30-40wpc with most speakers. I beleve most amplifiers fail in this regard.
I am a rookie too, but there are other explanations for pushing GOOD power. I can throw some concepts, but there are other folks who KNOW these things much better than me.
May be that's also why many friends of mine have multiple pairs of speakers paired with various brands of (dedicated) amps.
Ouch! That's expensive.
Since this is meant-to-be the ultimate 3-way speaker, that is truly the least of the concerns.
Well... it'll be the best speaker I can build in about 5 cubic feet. I don't know that it'll be the "ultimate" speakers. Certainly there will still be folk seeking 100db/2.83v for their 300b SET amplifiers. There will still be folks seeking big pro-audio monitors. There will still be folks who want he warm sound of flexible cones. There will still be folks wanting a smaller speaker for the WAF (Wife Acceptance Factor). etc. etc.
Is there any preliminary speculation of the dimension yet?
It'll probably be about 13-14" wide, about 45", and very deep. The depth will be the "fudge factor" for the cabinet volume.
How big of a room is this 3-way speaker designed to perform in?
This decision will most likely be determined by your wife :lol: While there are some significant factors in room construction that DO effect bass response, a big 3-way speaker can be used in a very modest room. I heard this at CES, and I didn't think the larger 3-way speakers suffered in the hotel room suites. I think either of the larger rooms in my home will accomodate them just fine. They are @36'x15'x10' and 28'x23'x9 .
I just sent my Golden Tube SE40SE to Soniccraft for the "full Glowacki" upgrade. I think this amp might be the real deal after Jeff's work. I have grown to increasingly trust everything Jeff convey's. Intially I was hesitant, but his words keep coming true. Jeff said this amp will be "IT", when finished. I will certainly convey these findings when I hear them.
-
There is a query above regarding magnet degredation and Neodymium and mangnet degredation. I have learned some information that is worth sharing.
Yesterday I spoke with TC sounds regarding magnet degredation. They said the primary reason is one of conflicting electrical fields. The magnet can be considered a DC electrical field. The operating motor will generate inductance. This inductance creates an AC field. Over time, the AC field will travel across the DC magnet and slowly deplete the DC field.
The solution for this is simple - copper shorting rings. This application is equally effective with Neo and Ceramic magnets. This also explains why I haven't encounted any measured depletion of the 1801 magnets. They have shorting rings.
With specific regard to Neodymium magnets, in the past weeks 2 more drivers came up with Neo motors and underhung voice coils - Accuton tweeters. There is also an Accuton 7" driver with high sensitivity, a Neo Magnet, and underhung motor. This will make a profoundly expensive speaker. However, it'll be a first in many regards. All drivers will have underhung motors, stiff cones, neo magnets, and high sensitivity. Unless there something goes awry, this will be the configuration.
-
There is a query above regarding magnet degredation and Neodymium and mangnet degredation. I have learned some information that is worth sharing.
Yesterday I spoke with TC sounds regarding magnet degredation. They said the primary reason is one of conflicting electrical fields. The magnet can be considered a DC electrical field. The operating motor will generate inductance. This inductance creates an AC field. Over time, the AC field will travel across the DC magnet and slowly deplete the DC field.
The solution for this is simple - copper shorting rings. This application is equally effective with Neo and Ceramic magnets. This also explains why I haven't encounted any measured depletion of the 1801 magnets. They have shorting rings.
I cannot comment on the effect of motor inductance on magnets with no shorting rings in place. I have no experience in this realm. I have a hunch there are differences in magnet composition.
With specific regard to Neodymium magnets, in the past weeks 2 more drivers arrived in the marketplace with Neo motors and underhung voice coils - Accuton tweeters. There is also an Accuton 7" driver with high sensitivity, a Neo Magnet, and underhung motor. This will make a profoundly expensive speaker. However, it'll be a first in many regards. All drivers will have underhung motors, stiff cones, neo magnets, and high sensitivity. Unless there something goes awry, this will be the configuration.
-
However, can you explain why the 200wpc amp sounds better than the 35wpc push pull when the peak consumption is 30 watts? I believe the answer lies in the ability for an amplifier to push a GOOD 30-40wpc with most speakers. I beleve most amplifiers fail in this regard.
Indeed, being able to push a good 30-40wpc is the most crucial. I guess that's also the reason why more and more vendors are switching from Class A to ClassAB with only the first 15-50wpc working in ClassA. I think it can be safely assumed that for any given vendor (comparing to the vendor itself only), its Class A implementation is going to sound better than its Class B. From personal experince again in my rig :), using large scale orchestral CDs or (24+ inches) drum intensive tracks, the highest registration of amp draw I have seen is about 5 amp. Assume that reading is somewhat accurate and my speakers operating around 6 ohms averagely speaking, I2R tells us it is about 150W. Since mines are Class A, taking Class A efficiency (40-50%) into account, 60W is what the speakers demend of the eacho mono amp at the moment of the highest current draws. (I hope I am not too far off in this simplistic example). I completely agree that under the regular situation, good 30-40wpc would be sufficient. But during the demanding moments, amps with more headroom may be useful.
While there are some significant factors in room construction that DO effect bass response, a big 3-way speaker can be used in a very modest room.
A big 3-way speaker often prefers to perform in a bigger room. As you already point out, the room dimension will affect bass response. In a small room, which can't reproduce the bottem end, it will most likely to create bass booming problems. What will be the minimal dimension that the speaker needs in order to 'breath' comfortably as its design intended?
I just sent my Golden Tube SE40SE to Soniccraft for the "full Glowacki" upgrade. I think this amp might be the real deal after Jeff's work.
Please keep us posted regarding the impression on this newly modded toy of yours.
However, it'll be a first in many regards. All drivers will have underhung motors, stiff cones, neo magnets, and high sensitivity. Unless there something goes awry, this will be the configuration.
Does this mean the accuton underhung drivers are the top candidates for now?
Dave, this is looking more and more interesting. Perhaps I can swing by Dennis place again to audition the prototype when it is ready! :)
-
A big 3-way speaker often prefers to perform in a bigger room. As you already point out, the room dimension will affect bass response. In a small room, which can't reproduce the bottem end, it will most likely to create bass booming problems. What will be the minimal dimension that the speaker needs in order to 'breath' comfortably as its design intended?
Generally yes, but this depends on the intent of the woofer system design. I heard one very prime example of bass boom when I auditioned the PSB Stratus Gold several years ago. This speaker is allegedly flat to the low 20hz zone anechoic. The result in-room was massive boom due the room lift occuring @30hz. This lift is common in most rooms and beigins somewhere below @40hz. I thought the Hales Revelation 3 (Sealed F3 @31hz) was a also a bit too low, and boomed slightly. The 2nd best bass in-room bass balance I have heard was from the Hales Revelation 2 (Sealed F3@35hz). The best in-room response I heard was from the SCC300 woofer (F3@38hz). My woofer will have low Q sealed F3 of about 40hz.
I'll made a statement of opinion at this point, "The general room lift in most rooms is significantly better matched to the @12db sealed woofer rolloff than the @24db ported woofer rolloff. ?
A big cabinet woofer system can result in deep bass. A big cabinet woofer system can result in high sensitivity. My orientation is toward the latter. I don't really think bass boom will be an issue.
But during the demanding moments, amps with more headroom may be useful.
Yes, but the only time I need this is to dance with my boys.
This speaker will be capable of cleanly reproducing the power from a @200wpc amp. As such, using a smaller amp might make an owner feel less masculine. However, given normal listening, the very best system amp has just enough power, and no more (my 2 cents).
Does this mean the accuton underhung drivers are the top candidates for now?
Yes, but they are expensive. However, like the 1801, I am building this speaker for me. If somebody else wants one... okay :)
Dave, this is looking more and more interesting. Perhaps I can swing by Dennis place again to audition the prototype when it is ready!
Dennis probably will not be living in DC by the time this is completed. He is retiring and moving to Arizona. Further, Dennis may not have this prototype. It'll also require a different cabinet than what you saw (bigger and a backward leaner). Initially this speaker will arrive in Chicago in October of next year.
However, if you are interested in arguably the very best speaker currently made, I suggest you visit Jim Salk in Detroit www.salksound.com.
Dave
-
A big 3-way speaker often prefers to perform in a bigger room. As you already point out, the room dimension will affect bass response. In a small room, which can't reproduce the bottem end, it will most likely to create bass booming problems. What will be the minimal dimension that the speaker needs in order to 'breath' comfortably as its design intended?
Generally yes, but this depends on the intent of the woofer system design. I heard one very prime example of bass boom when I auditioned the PSB Stratus Gold several years ago. This speaker is allegedly flat to the low 20hz zone anechoic. The result in-room was massive boom due the room lift occuring @30hz. This lift is common in most rooms and beigins somewhere below @40hz. I thought the Hales Revelation 3 (Sealed F3 @31hz) was a also a bit too low, and boomed slightly. The 2nd best bass in-room bass balance I have heard was from the Hales Revelation 2 (Sealed F3@35hz). The best in-room response I heard was from the SCC300 woofer (F3@38hz). My woofer will have low Q sealed F3 of about 40hz.
I'll made a statement of opinion at this point, "The general room lift in most rooms is significantly better matched to the @12db sealed woofer rolloff than the @24db ported woofer rolloff. ?
A big cabinet woofer system can result in deep bass. A big cabinet woofer system can result in high sensitivity. My orientation is toward the latter. I don't really think bass boom will be an issue.
But during the demanding moments, amps with more headroom may be useful.
Yes, but the only time I need this is to dance with my boys.
This speaker will be capable of cleanly reproducing the power from a @200wpc amp. As such, using a smaller amp might make an owner feel less masculine. However, given normal listening, the very best system amp has just enough power, and no more (my 2 cents).
Does this mean the accuton underhung drivers are the top candidates for now?
Yes, but they are expensive. However, like the 1801, I am building this speaker for me. If somebody else wants one... okay :)
Dave, this is looking more and more interesting. Perhaps I can swing by Dennis place again to audition the prototype when it is ready!
Dennis probably will not be living in DC by the time this is completed. He is retiring and moving to Arizona. Further, Dennis may not have this prototype. It'll also require a different cabinet than what you saw (bigger and a backward leaner). Initially this speaker will arrive in Chicago during October of next year.
However, if you are interested in arguably the very best speaker currently made, I suggest you visit Jim Salk in Detroit www.salksound.com.
Dave
-
Hi Dave,
Keep experimenting with the 3-way until you get it right and I bet that others will want one too; me included. :D
I have a question about the mid range woofer. One of the advantages of a 3-way is that, if designed properly, the mid-range woofer can handle the whole vocal range from approximately 300 Hz to 3 KHz without any crossover in that critical region. Accuton has a number of woofers that could fit the bill (3.5" woofers all the way up to 7" woofers). My basic understanding is that larger woofers will handle the low frequencies well but may "beam" (become very directional) with the higher frequencies. Smaller woofers will have wider dispersion characteristics with higher frequencies but sacrifice the low frequency reach of a larger woofer. Have you experimented with different size woofers for the mid range and do you have a preference regarding sound? (I have not heard any Accuton woofers but the C79-6 seems ideally suited).
I also noted that you are designing a "backward leaner". Is this to time align the drivers or is this only for asthetics?
Thanks for all of the update information and keep up the great work!
Tom
-
...I have not heard any Accuton woofers but the C79-6 seems ideally suited ...
The Accuton C90-T6 6.5" midrange driver looks pretty good with an even flatter FR (+/-2db 120hz-7khz & smooth rolloffs), wider recommended bandwidth (120hz-6khz vs C79's 200hz-4khz), neodymium magnet, titanium voice coil former... It's 93db claimed sensitivity would not suit the Accuton tweeters but would go very nicely with other high end tweeters (most ribbons).
-
However, if you are interested in arguably the very best speaker currently made, I suggest you visit Jim Salk in Detroit www.salksound.com.
Umm, Dave, have you heard the Orions, lately? :wink:
Still lovin' my 1801's, though. They're now in the master b-room being driven by a Panny 45. Very nice.
Andy
-
There needs to be a HT3 versus SL Orion shootout and I'll be glad to have it at my house... well the wife may not approve. So, we'll host it at Andy's house while he is gone. :D
Then we can throw in the Eton 11.2s which are a bargain 3-way in comparison.
-
However, if you are interested in arguably the very best speaker currently made, I suggest you visit Jim Salk in Detroit www.salksound.com.
Dave
Dave,
I am not sure if they are the "best" out there, but I am very willing to say that they are one of the "best" out there in terms of sound, quality, and value.
Also wanted to say "kudos" to you for recognizing a peer of yours and not starting some flame war or feeling the need to start a turf battle.
I wish you continued success.
George
-
There are several things above for commentary. I hope this response will address all of them.
I have experienced the midrange from many respectable drivers, Focal Kevlar, Accuton C95, Zellaton, Scanspeak (many), Seas 7"-8", and some other paper cone drivers 5"-8". My summary is as follows.
1. As frequency rises, a larger cone will beam, and the in-room response will generally decrease. If this is avoided, using a larger cone in the midrange is a non-factor.
2. As frequeny rises, a larger cone experiences different physical stress at the same spl production. The larger cone will have less movement/acceleration. The larger cone has a greater distance between the voice coil and edge to firmly support/hold rigid. I found little/no difference in midrange sound quality between the W18 and W22 Seas drivers. The only real difference between these 2 drivers is the cone size.
3. IMO, the primary factors for an effective midrange driver and implementation are.
a. A rigid cone
b. Avoiding cone resonance
c. Avoiding thermal compression
d. Flat response on & off axis
e. Low motor distortion
In these regards there are many midranges that appear good. The best appears to be the new Accuton C90 on paper.
As a side note, I developed a very good crossover for the Accuton C95 and OW1. It sounds good, very good, but not really better than the Seas W18 and OW1. I think the bass from the C95 is better, and midrange from the C95 is more... natural. However, the impact is not significant enough to warrant another product. The same was true with the SEAS W22 and OW1F experiment.
I am not sure if they are the "best" out there, but I am very willing to say that they are one of the "best" out there in terms of sound, quality, and value.
I agree, that's why I used the word "arguably" in my initial statement. Certainly there are other speakers on par with the Salk 3-way. The Joseph Audio Pearl, John K's NAO, and S.L. Orion are in the same league. The Burmester B99 might be better than the Salk 3-way, but I'd really have to hear the speakers in the same room. There was also a big Kharma speaker on par with the Salk 3-way.
Umm, Dave, have you heard the Orions, lately?
Nope, but I am comfortable conveying that any of the bigger 3-way speakers via the DIY guys will sound better. For most, spending the extra $3k is very unwise. However, 3 of my customers have upgraded over the years, and appear pleased.
1. S.L. Orion
2. John K's NAO
3. Jim Salk's 3-way
Also wanted to say "kudos" to you for recognizing a peer of yours and not starting some flame war or feeling the need to start a turf battle.
Well, that's because Jim and I completely understand the relative "turf". We both have a relatively solid financial foundation that has nothing to do with building speakers. We also both realize there is no real possibility of developing a solid financial foundation through building speakers :) There is no sense arguing over financial turf when there is no real financial turf to obtain.
And... Jim does very good work. Jim is good, good, good for the hobby of speaker building.
Dave
-
Well, to add to what Zybar mentioned....I heard the 1801's almost exactly 3 years ago and never forgot them.
Jackman brought his down to the Marblefest that had Peter Thompson from the Netherlands meeting Klaus from Indy.
The 1801's did EVERYTHING better than my nOrh marble 9.0's except deep bass.
That session was one of the reasons why I went up to listen to Jim Salks HT3's at his house early this year. Jim has mentioned that the HT1's were based on the 1801's, but used a different tweeter. So by extension, the HT3 came from the 1801 as well. The XO's of the Ellis and Salks were all done by Dennis Murphy.
Anyway, the HT3 is a wonderful speaker. I'm sure whatever 3 way Dave comes up with will be an amazing speaker as well.
Certainly one I'm looking forward to hearing.
As to the best speaker in the world, I'll leave that up to people that have heard every speaker in the world. As for me, everytime I walk past my speakers, or listen to them, I get a smile on my face, or tears in my eyes (in a good way).
-
Yes, but they are expensive. However, like the 1801, I am building this speaker for me. If somebody else wants one... okay icon_smile.gif
If these accuton drivers are really all that, I actually would seriously consider dropping extra dough. Just keep me posted once you gotta prototype some of these drivers.
I have been paying some attention to Jim Salk's wonderful HT3(a). Too bad I haven't found anyone has one in Baltimore/DC area, otherwise I would love to audition it. They look pretty sweet and I believe they should sound at least pretty good too, especially if they are comparable to Kharma speakers.
Thinking of xover, will the 3-way have a passive and/or active oxver?
In term of cabinet, have you had much time to experince with different materials? Are MDF and hardwood still being used as the primary material for cabinet?
By the way, thanks for the willingness to discuss and share much of design concepts in public. May you have a wonderful weekend!
-
If these accuton drivers are really all that, I actually would seriously consider dropping extra dough
These are my thoughts too.
Too bad I haven't found anyone has one in Baltimore/DC area, otherwise I would love to audition it.
If you manage to wander through Detroit, I recommend you stop at Jim's home for a listen.
Thinking of xover, will the 3-way have a passive and/or active oxver?
... probably passive
In term of cabinet, have you had much time to experince with different materials? Are MDF and hardwood still being used as the primary material for cabinet?
Frankly, if the cabinet is solid, fancy/different materials really don't matter much IMO. Sure, there are many THEORETICAL issues extant, but they really aren't very important. Concrete, Granite & Corian might look pretty slick, but many extremely good speakers were made and will be made with MDF. If the cabinet is solid, the material really doesn't matter.
Given the broad spans of lumber on this cabinet, there will be very little/no hardwood. This is simply because hardwood expands & contracts across the grain significantly. If this "across" distance is too great, the lumber will split.
Also, I suspect this speaker will sound slightly better than many others. However, when compared to the very best speakers extant the difference may be minimal. I really don't know the audible impact of a good underhung motor completely integrated into a speaker system. However, many subwoofer guys rave about these motors. Other folks rave about ATC and Skanning and and everyone seems to agree that underhung is theoretically the best. They are surely the most expensive.
-
Dave, if you get a few spare moments, would you mind taking a stab at my questions posted toward the bottom of page 2 (4 posts up from the bottom)? I wanted to make sure I was interpreting your earlier comments correctly.
Thanks!
-
Sorry for my very slow response to this. Your question is quite substantial. I delayed due to time, then got wrapped up in other stuff and... forgot about it.
First, I should have used the term "reactive" instead of "reflection" in my statement. While I was considering what the amplifier endures due to the varied loudspeaker impedance load as "reflection", this is not accurate given the common use of electrical reflection. Component video folks use the the term reflection to describe the phenomena during impedance mismatch, and I should not have used this term.
1) Impedance is a combination of resistive (real component) and reactive (imaginary component) contributions
2) The reactance of a component varies with frequency
3) Resistive loads are easier for an amplifier to drive
4) Signal reflections occur when two components have mis-matched impedances (with an acoustical result generally described as "smearing" of the sound)
5) Variations in a speaker's impedance curve mean that mis-matches with the amp will almost certainly occur at particular frequencies - even if the amp is well matched to the nominal impedance of the speaker
These statements are correct.
I feel it's important to add that with 99% of amplifiers, the impedance variation is not a problem. This is simply because they are over-engineered and over-built. This is necessary to accomodate the common impedance swings extant in 99% of loudspeakers. I suppose the term "over-built" could also be termed "appropriately-built", but what I wish to convey is the industry has grown to accept increasingly difficult loudspeaker loads, and passed the burden to the amplifier folks. I believe this is true with respect to loudspeaker nominal impedance, loudspeaker impedance variations, and loudspeaker sensitivity. The industry has changed dramatically from the simple tubes and high sensitivity speakers of the 1950s.
Digressing....
Certainly a SET 300b amplifier is the incorect application in 99% of systems today, but given the right loudspeaker, there IS something very special about the SET 300b tube amp.
Digrressing further...
Those old Pilot 232 and Pilot 240 tube amps are very solid units. With some fresh capacitors they can sound very nice. There is a reason these pieces of rusty hardware continue to sell for $200+ on ebay.
Back on track...
Assuming that I have all of that correct, what I was trying to isolate from your statement above was whether a flat impedence curve necessarily means the speaker is primarily a resistive load and therefore easier to drive and a "bumpy" impedance curve means that a speaker is more reactive in nature and therefore harder to drive?
Yes, this is my understanding.
I realize that impedance peaks at particular frequencies indicate regions of increased reactance, but I wasn't sure what you could assume about the overall ratio of resistive to reactive. In otherwords, could the impedence curve be perfectly flat, but still dominated by the reactive contribution?
I don't think so. I believe that if the impedance curve is flat, it's flat. It will be a more benign load.
Is it as simple as reduced current demand = less thermal compression = better dynamics? If so, I still need the connection to impedance...
There are 2 answers.
1. Yes, Reduced current demand = less thermal compression = better dynamics.
2. A flatter impedance load will be easier for the amplifier to drive, and the amplifier design can be simplified (i.e. less feedback and less parts).
Eventually I'll know if these 2 factors are truly significant :) The theory certainly looks good, but not all things that look good on paper have an impact in the listening room.
-
And.... I find another thread that I missed a response to! Sorry for my tardy reply, but thank you for the clarifications, Dave! Let me know when you find out if those 2 factors are significant! :)
-
Lately I have been working through a book titled, "Modern High-End Valve Amplifiers", but van der Veen. It's a very solid study. He comments on page 29, "It is useless to hope that the output transformer will work optimally over such wide ranges of impedances and frequencies. A much better solution is to provide the amplifier with an output impedance that remains constant throughout the entire audio band."
It appears my initial thoughts are correct - in theory.
Dave
-
Hi Dave,
hope you had a nice family's Christmas day.
Did you progress in your 3-way project? Finalized your drivers' choice?
Regards,
:beer:
-
... Christmas was very nice. My boys (age 3 and 5), make the experience feel very complete.
... Still no woofers from TC sounds :( . I really can't do anything tangible until these arrive.
-
David,
What size TC Sounds woofer, 10", 12"? What size will the bass cabinet be?
Thanks
-
12"... @ 4' of cabinet.
Dave
-
12"... @ 4' of cabinet.
Dave
My conversions might be a little fuzzy, but I think that is 6912 cubic inches interior dimensions. So 24" tall would be reasonable, 16" wide would work. Does that leave 18" deep? Add 1.5 inches in all directions for the cabinet and outside dimensions might end up at 19" wide and 21" deep.
Is that pretty close to what you are thinking about?
Sorry if this was covered earlier in the thread.
-
Your dimensions appear to yield the appropriate volume, but the intended cabinet will be a taller/narrower backward leaner housing all 3 drivers. I think these look better than a 2-piece speaker with a big square bass cabinet. In all of this, the project is moving veeeery slow. Until woofers arrive from TC sounds for testing, it's only a concept.
-
Your dimensions appear to yield the appropriate volume, but the intended cabinet will be a taller/narrower backward leaner housing all 3 drivers. I think these look better than a 2-piece speaker with a big square bass cabinet. In all of this, the project is moving veeeery slow. Until woofers arrive from TC sounds for testing, it's only a concept.
It sounds like it will be a nice speaker. I'm pretty sure I saw a prototype of a cabinet that matches that description that either you posted here, or you posted on your website. This would have been a year or two ago.
Edit: Yup, found it...
(http://www.ellisaudio.com/boot3way.jpg)
-
Hi Marbles,
I believe that is the first conceptual cabinet for Dave's 3 way.
The faces you see in the picture are a flat fronted, trapezoid baffle. In recent posts Dave alludes to a completely different design using a leaning front baffle.
alla Usher AC10
(http://www.audiocircle.com/circles/galleryimage.php/album14/u_AC10.jpg)
I can't wait to see it myself :D
-
Correct,
The initial thought was to use a trapezoid with a flat baffle. I learned subsequently that a leaning baffle makes the crossover & impedance more favorable. The variables just work better this way.
Using a mechanical means to advance the woofer phase makes the electrical proposition better.
I don't think I am going to attempt a rounded back cabinet though. It'll look more like something from Avalon or Wilmslow.
(https://secure.wilmslow-audio.co.uk/acatalog/prestige2.gif)
(http://www.avalonacoustics.com/images/eid12.jpg)
Dave
-
Very nice looking. Best of luck with this speaker.
I hope TC Sounds gets moving, so you can proceed.
-
IMHO,
Aesthetically spoken, I guess the main issue is about the front firing 12". In that way, I have to say that Avalon's designs, with their cutted angles, are an adequated response, allowing to perceive less width of the global shape; straight cutted lines work very well in this matter and furthermore are modern design principles notably used in cars' aesthetics, at least in Europe (BMW, Ford-europe, Renault...)
But these shapes could be viewed as "not soft enough" for someones.
Dave and others, any suggestions/links to commercial designs about how to reduce the visual width ?
:beer:
-
Aesthetically spoken, I guess the main issue is about the front firing 12".
Exactly :!:
When I discussed the woofer with TC Sounds, we agreed the very best approach for high sensitivity would be a 15" woofer. We also agreed that it would look way too huge and nobody ( or nobody's wife) would buy a speaker with a 15" front-facing woofer.
There are decent looking 3 speakers with big cabinets that look acceptable IMO: Avalon, Kharma, and Usher. I really don't know of any others. Many years ago JBL made a trapezoid (the initial look), but I really need a rearward leaning speaker. I am open to suggestions in this regard.
-
I really need a rearward leaning speaker. I am open to suggestions in this regard.
I guess that for many technical/economical reasons :wink: , you don't want to go to a side firing woofer...
So, my better suggestion is to visually reduce the width by creating a black-painted surface, englobing the tweeter and mid, and widening towards the woofer; all the other parts could be clear veenered . All this, in conjonction with a few cutted angles.
IMHO, difficult shapes to build aren't necessary in this matter.
"Easy to build" for you and your customers probably is one of your goal, even if not the main, isn't it?
I guess you are thinking of slanted front and rear baffles, with horizontal top and bottom...but a simple parallelepipedic shape could be used if you use a little stand to lean the enclosure backwards; in such a way, no need of different angles than 90° to build the enclosure.
:beer:
-
I guess that for many technical/economical reasons , you don't want to go to a side firing woofer...
Well not for those reason. I have heard a few side-firing commercial speakers and thought the side-firing woofer didn't work very well. Front firing woofers seem to sound a slightly better to my ears.
So, my better suggestion is to visually reduce the width by creating a black-painted surface, englobing the tweeter and mid, and widening towards the woofer; all the other parts could be clear veenered . All this, in conjonction with a few cutted angles.
So... kinda' like the bigger Kharma speaker.
As you offer considerations/ideas, please do keep in mind the cabinet will be 4 cubic feet internally. This is quite large, and the midrange chamber/tunnel must be considered too.
I guess you are thinking of slanted front and rear baffles, with horizontal top and bottom...
Yes.
but a simple parallelepipedic shape could be used if you use a little stand to lean the enclosure backwards; in such a way, no need of different angles than 90° to build the enclosure.
I thought of this, but the appearance is slightly... cheezy/cheap. In an "economical" speaker a single spike in the front to create a backwards lean would be fine. For a better looking speaker, the simple spike is less than desirable - according to my wife. Some complexity in the construction process is acceptable for aesthetics. However, a round back for the enclosure is not acceptable. This is way too much work. Also, my wife really doesn't prefer the appearance of a rounded back cabinet.
-
Hey Dave,
I am really loving the concept of this new 3-way speaker. I hope that TC Sounds sends you those woofers soon so that further R&D can continue.
All the best with the design and thanks for the update.
Take care,
Tom
-
Soon.... :)
This is very optimistic, but I conveyed that I'd rather have the woofers "good" than arrive soon.
I have learned that ya' can get stuff good, or cheap, or fast. But, ya' can never get all three. I am prone towards the "good" end of the spectrum.
-
Hi Dave,
Judging by the added level of complexity to the cabinet, do you still intend to offer this speaker as a kit?
If so, are you planning to collaborate with a cab manufacturer to produce mdf flat kits? and/or completed, and semi-finished, cabinets?
Thanks.
-
I will not offer a cabinet kit. I will only offer the electronic guts as a kit.
Also, the cabient plans will be filled with pictures and dimensions, but will have SIGNIFICANTLY less step-by-step instructions then the current 1801 plans. A rookie will not be able to obtain good cabinet results in 2 weekends time.
Dave
-
Hi Dave-
Is the current thought still to use the same drivers as the 1801 only supplanting them with the tc sounds driver? Or has the newer seas excel driver caught your eye or maybe one of the nice (and expensive) accuton midrange drivers would work as well?
Jim
-
Thanks Dave,
Glad to hear the kit will still be available :!:
I'm probably jumping the gun a bit here, but I think there will be some interest in an MDF flat kit, for most of us rookies :)
Perhaps a group buy from a reputable CNC machine shop would be an option some of us could consider. I'm sure this can be coordinated behind the scenes by the new owners.
I'm open to recommendations from anyone for a reputable machine shop, and I'll be happy to begin some preliminary research for the group.
Happy new year Dave! I hope it is a grand year for you and your family.
Warm regards,
EP
-
I... really don't foresee a CNC MDF flats kit from me, or... anyone. The primary reason is shipping weight and potential for damage. The cabinets will weight 150lbs +. Shipping this quantity of weight is expensive using conventional methods, and the likelihood of damage is great.
However... If I shipped $100k annually via pallet, the cost per pallet would drop to @ $80. Unfortunately this isn't going to happen. The cost per pallet will remain in the $200-$300 range.
Another consideration is the kit will be... expensive. Very expensive. I am not going to artificially increase the prices, but the raw cost of components will be expensive. Given this cost, I don't think the number of customers will warrant a group purchase of cabinets, or flats-kits.
I do appreciate your enthusiasm, but remain a bit pessimistic about some of this.
My primary thought is... getting done with my current customers... getting some woofers and... building a prototype.
Dave
-
I thought of this, but the appearance is slightly... cheezy/cheap. In an "economical" speaker a single spike in the front to create a backwards lean would be fine. For a better looking speaker, the simple spike is less than desirable - according to my wife. Some complexity in the construction process is acceptable for aesthetics. However, a round back for the enclosure is not acceptable. This is way too much work. Also, my wife really doesn't prefer the appearance of a rounded back cabinet.
Have you thought about a 2-piece design? To give a modern example; something like the Wilson WATT/Puppy combo.
The top part would be the complex cabinet, with sloped front panel (a truncated pyramid, in essence). I built a similar cabinet and it was a pain, but probably not as bad as the full-size cabs you showed pictures of. :)
The bottom woofer cabinet then becomes fairly straight-forward with no compound angles.
It might be easier for customers to move around too.
Hmm... I note that Salk is doing something similar, although I think his speakers somehow look awkward.
-
I have thought about a 2 piece cabinet, but these generally don't have asmuch horizontal distance between the woofer and midrange to account for the electrical phase shift. Moving the woofer down low on a sloped cabinet might offer 6-8" of horizontal shift to accomodate the phase differences between midrange and woofer. This compares to perhaps 2-3" of differnce in the Wilson Watt configuration.
I have considered that a 2-piece setup can actaully look good. I think this speaker looks pretty decent http://www.avalonacoustics.com/sent.html, and has enough volume in the bass cabinet to allow higher sensitivity and/or deeper bass. While the Wilson Watt has 2 woofers, the cabinet remains relatively small. Bass will resultantly suffer in comparison. Bigger is better with regard to bass cabinets. Unfortunately, these big cabinets DO get friggin heavy and very awkward in the workshop. It's very difficult to avoid damage when working on very big cabinets. If I used 2 cabinets, the lower bass cabinet would still have to be very big... and heavy.
-
Hello David,
Is there any plan/possibility to actuate this wonderful 3-way design this year? 8)
-Howard
-
I am visiting with the folks at TC sounds in SanDiego later this month and will know more concerning the status of woofers. This is currently the long-pole in the timeline.
Dave
-
Hey Dave,
We (at least I) would love to hear anything that you could share following your meeting with TC.
Thanks.
Tom
-
Dave: what is your current estimate on the cost of this 3-way kit?
-
I have thought about a 2 piece cabinet, but these generally don't have asmuch horizontal distance between the woofer and midrange to account for the electrical phase shift. Moving the woofer down low on a sloped cabinet might offer 6-8" of horizontal shift to accomodate the phase differences between midrange and woofer. This compares to perhaps 2-3" of differnce in the Wilson Watt configuration.
I have considered that a 2-piece setup can actaully look good. I think this speaker looks pretty decent [ur ...
I think it also depends upon where the x-over point is. If you made a smaller 1801 with a 6.5" driver, you might be able to cross over to the sub at a low enough point that phase shift is less worrisome. You could even place the woofers on the sides of the subs and that would give you plenty of setback.
A separate sub enclosure will be no larger than, and possibly smaller than, a big 3-way box. It might be easier to work with in the shop. But it also might give you two new models to sell. The sat by itself as a smaller speaker for small rooms, surround use, etc. Then the whole 3-way system would be an option for those who want it. People could even buy the sats with the intention of upgrading with the subs. That's good for people who have limited funds. :)
Anyway, just my thoughts...
-
Hello Dave,
Besides woofer, do you have tentative tweeter and midrange (preferrably underhung) drives yet? Maybe I have missed this, have you decided the size of the woofer? I remember reading 15" is no-no because of WAF. Is the woofer going to be a single unit or the possible dual woofers design?
Thanks,
-Howard
-
David Ellis Mon Feb 13, 2006 11:31 am
I am visiting with the folks at TC sounds in SanDiego later this month and will know more concerning the status of woofers. This is currently the long-pole in the timeline.
Hi Dave,
Assuming you had your meeting with TC Sounds, inquiring minds would like to know of any new news.
Thanks.
Tom
-
Is the 3-way done yet? Check the date.
Hope your visit to San Diego went well, perhaps moves you back to the West coast (well Montana was close).
What is your target sensitivity? Getting close to 92db at 6-8 ohm would put it in a unique/highly-desirable position.
Al
-
The SanDiego visit was very nice, but... the interaction with TC Sounds is very, well, mediocre. Due to several contributors, they wish to return to a 10" woofer. As with all things, I am open to divine inspiration and God's will. However, I am lukewarm on the idea of a 10" driver. I will henceforth convey my sentiments on the matter. This decision needs to be made before tomorrow morning. Any comments after tomorrow morning will have no impact on my decision.
A 12" woofer project would include the new fangled Accuton drivers, and cost @$3k$ for the KIT. It would have 91-92db sensitivity in a BIG cabinet and have solid bass.
A 10" woofer project would include SEAS & Hiquphon drivers and cost @$1500 for the KIT. It would have 89db sensitivity in a good-size floorstanding cabinet and have solid bass.
Both configurations would be 8 ohm sensitive (7ohms low dcr) and both would have a sealed bass roll off in the high 30s.
The cabinet size is directly proportional to the sensitivity. Keeping all other things equal, adding 3db of sensitivity doubles the cabinet size.
I could move the T/S parameters tighter and obtain more sensitivity, but the bass depth dissappears.
I could use electrical compensation to artifically improve bass response, but the result is thermal compression in the voice coil.
I think the "testosterone" in me wishes to have a bigger, more expensive, and more sensitive speaker. However, that speaker would be friggin huge, and heavy, and I'd no respectable housewife would allow such a speaker in her living room. I'm also NOT excited about building whoppin' huge cabinets. They are a pile of work and very easy to "ding" in the workshop. I think the $1500 10" SEAS/Hiquphon project is a smarter decision. And, candidly, have you heard any midrange/tweeter drivers that sounded clearly better? I haven't. So, while the Accuton project may have sex-appeal, I don't really know that it will sound better. I should probably ignore my male urges, and build what is a the wisest speaker.
What do you think Al? Would you really spend 2 x $ to go from 89 to @91db sensitivty and use Accuton drivers?
Dave
-
Hi Dave,
I'm excited on further development with the 3-way project. As with many products, there's always give-and-take. Have you considered both offerings? Having options may serve and suit more customers, as individual needs and wants always differ.
Doug
-
Just speaking for me, I would have gone for the 1801 but when push came to shove, I would like deeper extension that only a larger woofer can manage. You can't beat the laws of physics. Since I have an AVA 350 EXR amp, sensitivity is not a large issue for me so my vote is to go for the less sensitive and less expensive speaker assuming the sonics are identical. The spouse acceptance factor is only a bonus.
Good luck with your decision Dave and thanks for the update.
Tom
-
I've been waiting a long time for a kit that will go head to head with Avalon , Kharma, and the like. I think you'll offer a very special, unique kit if this speaker sounds like I think it will.
This might be the testosterone talking but....I'll be first in line for the Accuton Kit :!:
-
What do you think Al? Would you really spend 2 x $ to go from 89 to @91db sensitivty and use Accuton drivers?
Dave.
Dave,
I am not really a potential customer since I am very happy with my current speakers (Salk HT3's), but why not throw my two cents in?
Go with the less expensive and sensitive kit. It really doesn't seem worth it to just go up a few db's in sensitivity. Now if you were jumping up to say 95-97 db's, that would be a different story as it would allow for different types of amps to be used.
Having owned some very big speakers (VMPS RM 40's) previously, I would caution you on going that route. Shipping becomes an issue as does fixing problems in the field. Plus there is the WAF to consider.
Anyway, best of luck in your decision.
George
-
Dave,
I am not really a potential customer since I am very happy with my current speakers (Salk HT3's), but why not throw my two cents in?
Go with the less expensive and sensitive kit. It really doesn't seem worth it to just go up a few db's in sensitivity. Now if you were jumping up to say 95-97 db's, that would be a different story as it would allow for different types of amps to be used.
Having owned some very big speakers (VMPS RM 40's) previously, I would caution you on going that route. Sh ...
I hope this doesn't come accross as a debate....
I think the demographic interested in a state-of-the-art 'Kit' will not be concerned so much about WAF because most of us willing to spend that kind of money have a dedicated space, or wives who understand our passion for this insane hobby.
From my reading, I believe Dave will only offer this speaker as a 'kit' therefore the shipping issue is a non-issue.
The Accuton kit, at 2x the price of the Seas kit is expensive, but still 1/4 the price of a similarly designed Avalon, for example.
Can you tell I'm passionate about this? Dave just let me know where to send the cheque! :lol:
Hohumm....here's hoping.
-
Dave,
Though I think an Accuton 3-way would be very unique and highly desirable, save the Accuton for another day. The price is not an issue for this level of performance. But I agree that the size is significant. No sense building a 3-way that performs similar to the HT-3 but is bigger. If it's going to totally outclass the HT-3 and be up to the Isis level, then EP is right. We need to buy Spa visits for our wife and they won't mind the size.
On the other hand, the Seas-Hiq 3-way for $1500, that has family resemblance in performance to the HT3 and is in a smaller, lighter package... that will be attractive and popular.
You should seriously think about using baltic birch plywood. You already have serious bracing, plenty strong and the light weight is another major benefit for shipping and moving around the house.
Go for the best 10" woofer even if it means adding to the kit cost (Volt, Eton, ScanSpeak Revelator for example). Sounds like you might have chosen the TC Sounds. Looks like it works OK for the HT-3 guys :)
Getting an Ellis 3-way done, completed will be a great accomplishment.
Al
-
Hi, DAve -- I'd recommend the non-Accuton, less expensive 3-way, too. And, I'd go for the deepest bass possible that integrates well with the mid and tweet. Sacrificing a few db of sensitivity for deeper extension is a trade-off that I imagine many of us would make.
For what it's worth, I, too, am no longer a potential customer for this 3-way, now owning a pair of Orions. But, I'd love to hear what you do come up with -- and, I'm still diggin' my 1801b's in the bedroom! :mrgreen:
Andy
-
If it is not too late, I'd personally suggest the Accuton setup with maybe a 12" in a smaller cabinet and biamp & add a LT to the lower cabinet. Noone on the planet offers an Accuton kit. Differentiate!
-
I vote for offering both.
-
So, while the Accuton project may have sex-appeal, I don't really know that it will sound better.
I'm sure you've already contemplated this, but I have to ask if for no other reason than to educate myself... :peek:
How would you really know which way to go (Accuton, SEAS, or both kits) when it appears that you haven't built prototypes of either, or at least a prototype of the Accuton? Is gambling on an Accuton prototype totally out of the question due to the high cost of materials and time?
It seems that synergistic magic happens unpredictably and something's true worth often remains a mystery until it becomes reality.
I do hope the best for you in developing the kit. With your capabilities, I'm sure it will be excellent.
-
I've owned a pair of SCC300 sub-woofers in 3.75ft cabs. Those, in combination with my 1801's, were used as sub/sats in my 2 channel system for a long time. I just don't get the issue with size. Yes they were heavy, but they don't compare to some of the line sources, or WMTMW systems people own.
I've had visions of a 2 peice cabinet for a large 3 way, and I think this would make the assembly more managable. I wish I had a CAD program. The 2 peice idea can still incorporate the same time-aligned backward leaning set-up, only it's split below the mid-bass and above the woofer. That could make this a much easier build for the DIYer. I remember lugging around my SCC300 woofer cabs; they weren't that bad. The bottom half of this speaker would be no different. :D
-
Great thread guys!
I have to say that Dave's 1801b's are the first speaker I was attracted to when I decided to go the DIY route. That is the reason why I have a pair of W18EX and W18NX to play with as well as the OW4.
But a 3-way design using the W18E and the Accuton drivers can be found on the web. Not all of the speakers using these drivers are offered in kits but people have completed designs and have posted results.
May I suggest, Dave, that you look into different drivers to the Seas and Accuton. How about PHL drivers? I am assuming the subwoofers you intend to use can play up to 300 Hz where they will be required to be low passed when using the PHL midranges.
I think the sensitivity of the PHL drivers as well as their midrange detail is exactly what you are looking for. Most importantly, you will have a kit unlike one I have seen yet on the web! Something I think you can be very proud of.
-
EP,
Have you seen the Lumen White from Austria? Check out the Silverflame and DiamondFlame.
http://www.shows.soundstagelive.com/shows/avtour2005/frk_showstoppers_3.shtml
Here are morer high-end speaker using the C90-T6:
http://www.isophon.de/pages/isophon.pages.php?id=en_801
Then there's always the Avalon Isis:
http://www.avalonacoustics.com/isis_specs.html
Talk about sex appeal. Trying to play both sides... it's a tough choice.
OW4 or C13/C24 for highs
C90 for mids
and 3 x C220 for lows
that would do nicely.
Al
-
EP,
Have you seen the Lumen White from Austria? Check out the Silverflame and DiamondFlame.
http://www.shows.soundstagelive.com/shows/avtour2005/frk_showstoppers_3.shtml
Here are morer high-end speaker using the C90-T6:
http://www.isophon.de/pages/isophon.pages.php?id=en_801
Then there's always the Avalon Isis:
http://www.avalonacoustics.com/isis_specs.html
Talk about sex appeal. Trying to play both sides... it's a tough choice.
OW4 or C13/C24 for highs
C90 for mids
and 3 x C220 for lows
that would do nicely.
Al
Hi Al,
I've drooled over some of those speakers for a while now :!:
I wonder if the C90 mid can be utilized with the Hiq tweeter and 10" bass driver???
I expect the extra sensitivity will be a waste, but perhaps a higher xo point to the tweeter would be a nice benefit. I'm also curious if the 10" 3way will be a time aligned, backward leaner. I didn't see this info in the 10" thread.
Although I'd be slightly dissappointed, I could easily live with a Hiquphon/C90/TC Sounds 10" :D .
Something about the W18 has me craving something different. It's not that I don't like it, but I suspect a more pure midrange driver would excel (no pun intended) in the mid band, potentially extending the pass band and reducing the stress on the tweeter. I'm far from a designer so I could be way off here.
I'm pretty stoked that Dave is close to finalizing some plans.
Good luck Dave!
-
Wow,
I didn't really think there would be such a significant response. Overall, it seems like the sentiment is towards a lower sensitivity speaker. However, at 89db @ 8 ohms, it'll still have a higher wattage sensitivity than @95% of available speakers.
There are many other fine gents who offered input. I will try to respond to the most prevalent issues.
How would you really know which way to go (Accuton, SEAS, or both kits) when it appears that you haven't built prototypes of either, or at least a prototype of the Accuton? Is gambling on an Accuton prototype totally out of the question due to the high cost of materials and time?
Well, the NEED for the Accuton driver rises from the sensitivity of the new C90 driver. There are extremely few good drivers having 92db/watt sensitivity. If the woofer has 92db sensitivity, the midrange must also have this. I must admit that I have NOT heard this driver, but assume that it will be on-par or better than the current line of Accuton drivers. I do think there are some issues regarding driver integration and synergy, there is nothing magical present.
I have spent time with the Accuton C95 driver in my workshop. I have heard the 5" Accuton midrange very recently. I have also heard the Lumenwhite speakers, Kharma, Avalon etc. IMO, the Accuton drivers are very good, but the only reason I would transition to them is:
1. Q.C. of the SEAS drivers declines.
2. The application of an Accuton driver works better. Example: This could be the case with the Accuton C79. Certainly Joe D' spent www.usheraudio.com money on the best midrange when asked to build Usher's best speaker. The application would also necessitate the use of the C90 midrange if the woofer was 92db sensitive.
... More to follow... it's dinner time.
Dave
-
I spent a bit of time with the Accuton C95 driver, and found it superior in the bass to the W18, but very slightly inferior in the midrange. I decided a change to the 1801 wasn't going to happen.
While I do believe the Accuton drivers are very good, most of the SEAS drivers are right on-par. This is true with one exception - the bass. I find the bass from the 8" Accuton clearly superior to the 8" SEAS. The midrange is very similar with the SEAS driver having a very slight superiority. In retrospect, I could have very easily used the Accuton C95 in the 1801 with slightly different results. I am certain many foliks would prefer the bass of the C95. However, at the time, I was very budget oriented with regard to the speaker. This is less true now, but budget/value remains a valid concern. Time and effort are a greater concern. I have a pair of C95's in the workshop, but they won't find a home in my personal speakers simply because there isn't enough difference to warrant my time and effort.
I found the Accuton drivers integrated very well in all speakers - except the Lumenwhite. I don't know what the issue was with these speakers, but I suspect the problem was not the drivers. A cohort of good hearing (Alan Sull) did mention that he really liked the Lumenwhite, so I suspect the problem was not the drivers. Accuton drivers are very good, the QC (by reputation) is top notch.
Soooo, it looks like the woofer will arrive in an 89db configuration with the remainder of the drivers yet to be determined. I'll most likely test the W18EX001 and the Accuton C89.
Oh, someone above mentioned PHL drivers. I heard one of their @ 7" midwoofer drivers with a very well designed crossover using a B.G. planar tweeter. I'll not convey the louspeaker builder, but the guy is VERY good. My opinion... is that PHL may produce some very good drivers, but this one isn't one of them. The chance of finding a @7" driver in one of my speakers is nil. This is my opinion only. Other's are welcome to disagree.
The 2 peice idea can still incorporate the same time-aligned backward leaning set-up, only it's split below the mid-bass and above the woofer.
I can mentally picture this but... Do you think the average houswife would allow a double box cabinet?
-
I've been waiting a long time for a kit that will go head to head with Avalon , Kharma, and the like. I think you'll offer a very special, unique kit if this speaker sounds like I think it will.
Jim Salk's HT3 speaker already does this, but isn't offered in a kit. I also believe the Linkwitz Orion and John K NAO are in this league.
Dave
-
David wrote this:
Jim Salk's HT3 speaker already does this, but isn't offered in a kit. I also believe the Linkwitz Orion and John K NAO are in this league.
- except that, like all active crossover systems, the sound is now probably limited by the electronics, rather than the speaker.
Cheers,
Hugh
-
On the other hand, the Seas-Hiq 3-way for $1500, that has family resemblance in performance to the HT3 and is in a smaller, lighter package... that will be attractive and popular.
You should seriously think about using baltic birch plywood. You already have serious bracing, plenty strong and the light weight is another major benefit for shipping and moving around the house.
Go for the best 10" woofer even if it means adding to the kit cost (Volt, Eton, ScanSpeak Revelator for example). Sounds like you might have chosen the TC Sounds. Looks like it works OK for the HT-3 guys
The HT3 is actually a very small 3-way speaker. I think Jim has about 2 cubic feet internally. I'll have 3+'. This is necessary for the sensitivity.
Baltic Birch... is this stable enough for veneer? Is the edge grain stable enough for veneer?
I think better plywood is easily good enough for bracing, but not suitable for the external veneered surface. I really don't think it's stable enough.
All of the drivers you mention have overhung motor structure. Mine will have an underhung motor structure. These cost @2x$, and are more linear.
-
- except that, like all active crossover systems, the sound is now probably limited by the electronics, rather than the speaker.
Yes :) I agree. I don't intimately understand the electronic crossover designs, but find it very convenient that folks dismiss the importance of quality parts in their active crossover gear. I discussed this with Frank VanAlstine. He is in agreement.
Most folks seem to think that an active crossover will "fix" all those nasty problems created by a passive crossover. They seem to forget all of the parts contained in their active crossover.
Thanks for commenting Hugh.
-
Thanks for all the very good responses Dave.
Each time I read your commentary I come away a little more knowledgeable :thumb:.
Will the 10" design still incorporate time alignment via sloped baffle?
Good luck with the R&D.
EP
-
Will the 10" design still incorporate time alignment via sloped baffle?
These terms are "tossed" too liberally by marketing departments IMO.
All speakers with coherent phase (i.e. phase aligned) on a flat baffle have the phase of the woofer 360 degrees behind the tweeter. This is accomplished in the crossover.
All speakers that are time aligned have the right tweeter wave and woofer wave arriving perfectly and at the same time. They are not 360 degrees out of phase.
Given a 2-way speaker, a simplified explanation is thus:
1. The woofer acoustic center is generally at the base of the cone. Adding an inductor to the woofer will delay the phase further at the crossover point.
2. The tweeter acoustic center is generall at the base of the dome. Adding a capacitor will advance the phase further at the crossover point.
To time align these drivers, the tweeter acoustic center must align with the woofer acoustic center. The offset is significant, and can be found on several ACI speakers. I'll not do this.
However, the baffle will most likely be sloped. A detailed explanation is complex, but... after doing a few 3 ways (and several 2-ways) it's possible to optimize the crossover with less components if the baffle is slightly sloped. This is just how things matriculate. When I thought (?) my observation was valid via testing, I conveyed it to some other knowledgable gents. They agreed.
So... the baffle will most likely be sloped, but the drivers will not be time-aligned. They will be phase coherent.
-
While I do believe the Accuton drivers are very good, most of the SEAS drivers are right on-par. This is true with one exception - the bass. I find the bass from the 8" Accuton clearly superior to the 8" SEAS.
Hi dave, I'm curious if you've tried out Scan Speak woofers? They are generaly considered to have better bass then the Seas offerings.
-
Indeed, and I do think Scanspeak woofers generally sound better than the SEAS offerings. I don't have any measurements to suppor this. I simply think the Scanspeak woofers sound more authoritative than the SEAS woofers.
However, the same is true when comparing the SCC300 woofer www.soniccraft.com to any Scanspeak woofer. The SCC300 woofer has more authority and snap than the Scanspeak woofers. There are many reasons for this, but I... am not an authority on these matters and therefore am hesitant to convey hearsay given my limited knowledge.
If a 10" woofer matriculates from TC Sounds, it will be compared with the SEAS L26 and W26 woofers in my basement. I feel obliged to at least try these woofers in a very solid a/b test before making my decision. One very simple advantage is THESE Seas woofers have is a 2" voice coil. This 2" voice coil has more surface area and will dissipate heat faster than the typical 1.5" voice coils from Scanspeak.
Dave
-
Indeed, and I do think Scanspeak woofers generally sound better than the SEAS offerings. I don't have any measurements to suppor this. I simply think the Scanspeak woofers sound more authoritative than the SEAS woofers.
However, the same is true when comparing the SCC300 woofer www.soniccraft.com to any Scanspeak woofer. The SCC300 woofer has more authority and snap than the Scanspeak woofers. There are many reasons for this, but I... am not an authority on these matters and therefore am hesitant to convey hearsay given my limited knowledge.
If a 10" woofer matriculates from TC Sounds, it will be compared with the SEAS L26 and W26 woofers in my basement. I feel obliged to at least try these woofers in a very solid a/b test before making my decision. One very simple advantage is THESE Seas woofers have is a 2" voice coil. This 2" voice coil has more surface area and will dissipate heat faster than the typical 1.5" voice coils from Scanspeak.
Dave
Hello Dave,
I hope you're doing well.
I'm sure your priorities are shifted to enjoying the summer and your family, so I feel bad for asking....but can you offer an update on your R&D progress?
Thank you.
-
Congrats on the new baby!
-
That's 11 days and nothing new?
-
Hi Dave,
I thought I'd take an opportunity to bump this thread and ask another question.
Re: Eton 11-581 11” HEXACONE Woofer
While you were in the middle of the R&D for a good woofer did you give this one a look?
It seems like it meets your criteria for sensitivity and VC diameter, so I'm curious to know what your impressions were.
Thanks!
Eton
11-581 11” HEXACONE Woofer
Weight: 9.2 lbs.
Low frequency reproduction
Excellent pulse response
Aluminum diecast basket
Flange 280mm
Cut-out 244mm
Depth 104mm
Znom 8 ohm
Re 5.2 ohm
Le@1kHz 0.69 mH
fs 21 Hz
Qms 6.68
Qes 0.31
Qts 0.30
Mms 67.3 g
Cms - mm/N
Sd 366 cm2
BL 12.4 N/A
Vas 153 ltrs
Xmax 5.0 mm peak
VC Ø 50 mm
Sensitivity
1W / 1m 91 dB
Nom. Power DIN 150 W
Net weight - kg
-
Congrats on the new baby!
Who? Dave had a baby?
I'm sorry I missed that one!
Well, whoever is having babies, CONGRADULATIONS!
-
Long time... :cry:
something new?
-
I get the feeling that this thread is being left to fade away.
I'm still hoping that's not true.
Cheers Hubert :thumb:
-
Wow,
guess I am late to this party. I would push for the best possible sound, period. If it meant a larger bass cabinet, then so be it. I prefer the sound of the SCC woofers vs any of the ScanSpeak or SEAS products, but the Eton's that I have heard in systems do seem to have a lot of the SCC magic of excellent authority and snap. 4 cubic feet is too large for a woofer cabinet? I guess I spent too many years seeing people spending mega dollars on uber amplifiers and speakers from my years of selling ultra hi-end audio. People that are passionate want the best possible. Size is secondary and only an a small obstacle, if that. I also agree that anyone that has the money to afford highend audio, will typically have a music room or a prenuptial to override any negative feedback.
For me, give me the best possible sound that I can afford. The requirements to achieve the best sound are just opportunities to see just how passionate I am about this hobby :-) These speakers simply do not sound that large to me, but that is my opinion. My wife has lived with Apogee Divas in our house before.
The difference between $1.5K and $3K is a pittance. Most people that are serious about their systems have wasted this much searching for their right cabling combo!
-
fading away......................... :cry:
:violin:
-
Hi David,
Can you give us your opinion on what T/S parameters values of woofers give more chances to get good bass, whatever loading type you use?
Cheers.
-
fading away.........................
Well, not... exactly, but there certainly hasn't been much action on this. It' would seem fair to provide an updated blog. Some of these snippets are positive, and some are not.
First, TC Sounds has promised me a prototype woofer 3-5 times over the past 2 years, but hasn't delivered anything. I have given up calling them. I believe TC sounds is able to build a very good product, but getting one of them is almost impossible. I heard via good rumor-mill that TC sounds also lost their largest commercial customer about 1 year ago. My guess is this happened because TC Sounds was slow to deliver, but this is only a guess. Subsequent to the loss of the large customer, TC sounds started openly selling their products for survival. I am sure they are good drivers, but they are intended for small-box/Low-sensitivity applications. The key T/S parameter in determining the relative sensitivity and design intent of a driver is the VAS. Specifically, anything larger than @ 160 liters in a 12" is desirable. There is nothing suitable in the current production drivers.
However, I still have some hope with regard to TC Sounds. They appear to be making an aluminum cone 15" driver with a really sweet motor assembly. It will use the cloth surround which should be very light/durable, and support high VAS :) . I have been very patient in this regard, and my patience might pay off :) . There is certainly a possibility that the T/S parameter set might favor a pro-sound application in the extreme. Fortunately, there are methods to raise the Qes and lower the F3 to an appropriate level.
Can you give us your opinion on what T/S parameters values of woofers give more chances to get good bass, whatever loading type you use?
This is a huge issue that really should take 10+ pages of text to complete. I will present a summary, but there will certainly be many gaps in my comments do to the large breadth of information present.
My general opinion on the matter is the very best set of compromises (not all things are a compromise) happens when the VAS is VERY high and the woofer can obtain 35-40hz f3 in a sealed enclosure. This will necessitate a large cabinet.
For a 12" driver, the SCC300 is darn near perfect, but the QMS is perhaps a bit high. BUT, there was a very reputable commercial manufacturer who conveyed that a high QMS woofer is actually superior. Candidly, I am not sure about this. There are compromises in the amplifier realm when considering the impedance peak presented. The steep phase angle created by a high impedance peak MAY cause undue reluctance issues in the amplifer and may be slightly detrimental. I have not tested "the same woofer" with a different QMS to verify this phenomena using various amplifiers.
There is also the issue of linearity and inductance. Given the SCC300 at normal listening levels the cone movement is VERY small and the linearity is not an issue. When driven with a good 100wpc my pair of SCC300 drivers might move @6mm peak to peak. And these woofers are quite sensitive. Hence, my believe is that among woofers, the issue of linearity is very small. The issue of inductance might more significant, but only as the frequency rises considerably. A staunch German and industry expert once coneyed that having shorting rings in a motor is only important at very high frequencies that approximate when inductance would cause the motor/driver frequency response to roll off.
Another snippet... A very knowledgeable "little bird" once told me the TC2 (2" voice coil) driver provided less distortion and better sound than the TC2+ (3" voice coil). This was verified by, hm, another "industry guy". The reason wasn't conveyed, but the spider length seemed to be important. This seems counter intuitive, but I am in no postion to disagree.
If I could have my ideal woofer, I suppose it would have a VAS of about 250 liters and a combination of QTS and Fs necessary to obtain a sealed F3 of 40hz. The dcr would not drop below 6 ohms, and the X-Max would be @ 15mm. The Qms would not rise higher than 4. The net result would be slightly more than 90db sensitivity in about 4 cubic feet.
The cabinet grows commensurate with sensitivity for every 3db of sensitivity (all other factors being equal), the cabinet size necessary will double. This means that my target bass system would be @ 2 cubic feet if the sensitivity were 87db@2.83 volts. This also means that my target bass system would be 8 cubic feet if the sensitivity were 93db@2.83 volts.
I will digress somewhat herein and rant. There is no magic way to sneak around the rules of physics with regard to sensitivity, dynamics, thermal compression, bass depth and cabinet size. The following are true.
1. Obtaining good bass dynamics requires high sensitivity. Less heat dissipation in the voice coil will result in a more consistent dcr for the voice coil and more snap in the woofer. If the voice coil heat rises after the first few pulses, the subsequent pulses will be encountering a high resistance voice coil. Hence, the initial wave encounters a cool voice coil and subsequent waves encounter a hot voice coil. The distortion is bad bad bad. It happens with ALL drivers. However, for every 3db increase in sensitivity, the heat generation is halved aa .
2. 4 ohm sensitivity loudspeaker drivers generate twice the heat of 8 ohm drivers. This is because while the voltage remains constant the amperage (and electrical friction) is doubled. Hence a 87db 8 ohm speaker will produce the same amount of voice coil heat as a 84db 4 ohm speaker.
3. Given the normal state of hifi, it seems that most speakers are @ 84db at 4 ohms. The result is a nice small cabinet and/or a very low F3. However there are compromises. Relatively speaking, a 90db at 8 ohm speaker will be 8 times better with regard to heat dissipation/thermal compression. This is because the 84db at 4 ohm speaker obtains this rating using an industry standard 2.83 VOLTS (not watts). The 84db at 4 ohm speaker will use 8 times MORE current than a 90db at 8 ohm speaker. The 84db at 4 ohm speaker will also generate 8 time more HEAT :flame: .
4. A small cabinet sealed woofer having a bass boost augmentation circuit is NOT a solution to the problem of thermal compression. The circuit is simply taking the low sensitivity response of a woofer at low frequency and applying more "heat" to the system.
It should be obvious that I DO think sensitivity matters - significantly. However, most folks aren't willing to spend the necessary money commercially for the big cabinet necessary to obtain the high sensitivity. Shipping methods, shipping damage, and cabinet cost are certainly contributing factors.
There are other issues too. Certainly muliple woofers will double the voice coil area. Underhung woofers offer something mysteriously good and favorable. The woofers from Adire seem to market well, and their XBL2 motor appears special, but I have heard this is a reincarnation of an old idea. Foam surrounds often provide better dampening and more favorable compliance. There are differences in spider quality. Voice Coil lead wires can impact the spider/cone during operation. Some drivers have steel terminals.
I would also like to convey some sentiments regarding my youth impressions and their validity today. In my youth, any decent/cool speaker was a 3 way. The old Cerwin Vega's and big JBL speakers sounded really great. The midrange was tolerable at best, but the bass was really cool. The music was mostly "nose", but this noise was garbled through the speakers and good bass was the goal. Today I continue to have a desire for that thump, thump, and will occasionally listen to Emotions/EWF "Boogie Wonderland" and similar music on my 3-way speakers. However, the other 99% of my music is conveyed much better on the 1801 (a 2-way). And, while there is some sound quality improvement when implementing a good woofer under the 1801 and unloading the midrange, the impact is NOT monumental. I think adding a woofer and unloading the 1801 midrange had about the same impact as replacing the BB2134 opamp with the BB2111 opamp in my CD player. Both certainly were improvements, but on par.
While you were in the middle of the R&D for a good woofer did you give this one a look?
It seems like it meets your criteria for sensitivity and VC diameter, so I'm curious to know what your impressions were.
Thanks!
Eton
11-581 11” HEXACONE Woofer
Yes - definitely. I heard this woofer in a big $$ Kharma speaker a few years ago. The bass was good, but inferior to the SCC300. There are many variables herein. The cones are equally stiff. The Eton was ported. The SCC300 was sealed. The T/S parameter sets are slightly different. The SCC300 has considerably more X-Max. The source gear and rooms were completely different too (different but roughly equal). Nonetheless, I feel very safe in my assertion that the SCC300 is a better sounding woofer - by a good margin.
//
Soooo, back on track with the 3-way blog... I still wish to eventually do attempt some flavor of fully underhung speaker. This will have to wait until TC Sounds finishes their pro-sound 15" woofer with the underhung radial motor. Hopefully the T/S set is amicable for a larger sealed speaker.
For now, I just purchased a pair of C79 midrange drivers. They arrived @ 1 week ago. The intent is OW1/C79/SCC300.
I still have to finish 1 more pair of customer speakers before I can begin this project. I am getting close.
Dave
-
Great write up Dave!! :thumb: I happen to agree with most of what you said. I think there is something really missing just looking at lower sensitivity drivers @ more watts at a certain level compared to a higher sensitivity driver at the same level and lower watts. I agree it is a low of dynamics due to the thermal compression. This is why I bought a quad of Lamda 15TDX drivers when I had the chance.
I can't say I have as good of a handle on the Q's as you though. This is a lesson for me.
-
I agree... great post and thanks for sharing!
Simple question: Why don't vendors put heatsinks on voice coils? The geometry would probably be a bit challenging, but it seems like an obvious thing to try... obvious enough that I suspect I'm missing something...
-
That is what a lot of phase plugs are suppose to be for, heatsinks for the voicecoil. whether it works or not, I have no clue. SEAS claims this for their Excel drivers and Focus Audio for their custom Eton drivers.
Maybe that is why underhung has a mysterious advantage?
-
I've heard that before, but always discounted it just because heat rejection requires significant surface area, and I never thought that the phase plugs added that much surface area. Anything helps, however, so if you want a phase plug anyway, you might as well grab any other low hanging fruit while your at it...
However, your comment did force me to rethink the question... and I have to imagine that having traditional fins (large area) could result in resonance issues. They could very will "ring" at all sorts of frequencies. You would need a thermally conductive material that was also very well damped mechanically despite the lightweight mass of the fin arrangement. I'm guessing that materials of that description would be hard to find at reasonable prices.
-
You realize, of course, that since I'm now thinking about this topic, I'm going to end up checking to see if my copper alloy SEAS phase plugs get warm after cranking up the music this evening! :lol:
Dave, my apologies for side-tracking your thread!
-
yeah I can't say I believed that claim either...seemed a little bit of a stretch for any significant amount of heat dissipation.
-
This is why I bought a quad of Lamda 15TDX drivers when I had the chance.
I was very tempted in this regard too. This is a tough niche though. I think that Lambda's vision was very correct, but the market for this is very small due to the cabinet size required.
I thought the Lambda motor was very good, and their T/S were also very desirable. However, it seemed like many of their drivers had soft/flexible cones. I am obviously a fan of stiff cones and steep crossovers.
Simple question: Why don't vendors put heatsinks on voice coils?
The voice coil is attached to the cone and moves with the cone. This assembly must be very light. A heatsink would add too much weight.
I've heard that before, but always discounted it just because heat rejection requires significant surface area, and I never thought that the phase plugs added that much surface area.
I am in thnis camp too.
The phase plug VERY sucessfully eliminates the resonance commonly between the dust cap and pole piece. I belive this is audible.
However, I believe that dust caps provide an "air pump" that moves more air past the voice coil and DO provide better bass. This is revealed when listening to the bass of the W18, Scanspeak 8545 and Accuton C95. Certainly there are many differences in these drivers, but those with the dust caps sound much better that the one with the phase plug. Also, more importantly, I discussed the matter with Phil Bamberg at BESL. Phil conveyed there was a solid research article in the AES conveying this truth. I firmly believe that phase plugs and dust caps present a driver design compromise. Dust caps are better for bass, and Phase Plugs are better for midrange.
I also remember reading a marketing pamphlet touting the advanages of the "Aluminum Baffle Heat Sink" on an Infinity Monitor - no kidding. :roll:
You realize, of course, that since I'm now thinking about this topic, I'm going to end up checking to see if my copper alloy SEAS phase plugs get warm after cranking up the music this evening!
Well, did it get hot?
Dave
-
Simple question: Why don't vendors put heatsinks on voice coils?
The voice coil is attached to the cone and moves with the cone. This assembly must be very light. A heatsink would add too much weight.
I guess I assumed that you could make one light enough (at least compared to the mass of a woofer voicecoil), but that it would then be prone to detrimental sympathetic vibrations.
You realize, of course, that since I'm now thinking about this topic, I'm going to end up checking to see if my copper alloy SEAS phase plugs get warm after cranking up the music this evening!
Well, did it get hot?
:lol:
Not that I obviously noticed by a simply touching the phase plug before and after playing the speaker for a while. Sorry, I don't have a thermocouple handy to provide measured results! :)
-
Part of this project is fading away. Another part might be resurrected.
The SCC300 woofer is gone :cry:. I thought about 30 were still available, but was mistaken. They are gone.
I learned the cultural expectation is daily calling American woofer manufacturers to obtain a product. This is a strange phenomena, but I have heard this from a few industry folks. I have the TC sounds number posted about 5" from my telephone and have started using it daily. Hopefully something positive will happen.
Dave
-
I chatted with Thilo at TC Sounds a few days ago. It was educational and provided optimism.
The tentative woofer @ 1 year ago with a cloth surround didn't function as hoped. The surround had to be very hard/dense to function properly. The result was a VERY low VAS and commensurately low sensitivity. So, Thilo knew this wouldn't work and had no "perfect" solution for me.
Currently, Thilo expressed an interest in conveying/purveying another motor project. I don't know what it is, and it seemed experimental in nature. Thilo only conveyed that the results should be superior to an underhung motor. I find this encouraging. Hopefull I'll have something in a few weeks. My only concern at this point is having a very compliant & soft surround. This is necessary for high VAS and high sensitivity.
Dave
-
I would probably lean towards a rubber surround. I think the fear of it rotting away isn't justified since you can replace them easily enough and many don't have their drivers that long anyway. I think rubber surround is spse to be superior to cloth in a few ways.
-
The initial hope was the cloth would have very good longevity and be very light and pliable. This didn't matriculate.
Foam is actually a very good material for a surround, and there are some very long lived foam surrounds constructed nowdays. A while ago I spoke with a gentlemen that manufactures surrounds in the USA. He conveyed that one of their foam surrounds has a 10 year guarantee under ANY conditions. I was very surprised about this. Certainly a common/cheap surround used for an automotive woofer placed in humid/salty air would have a life expectency of @ 2 years maximum. Offering a 10 year guarantee under these conditions seems absurd for an "average" foam surround. But, new chemistry has made a very positive impact.
Also, it seems like foam surrounds are making somewhat of a comeback. Many automotive subwoofers use foam surrounds, and I don't think this is a mistake from a durability perspective. I have seen several 20 year old speakers with perfect foam surrounds. Certainly there is a fair percentage of rotten surrounds on old speakers too. The difficult part in all of this is that consumers can't discern the difference. Getting a good foam surround is certainly a major boon.
However, for me, if the VAS of the prototype rubber surround is high enough, and the surround manages to control/damp any cone wobble, a rubber surround will be used. This is primarily because rubber WILL live forever, and folks spending big $$ on speakers want something that will last for 20-30 years.
Dave
-
:duh: I said rubber, but meant foam. :duh: Rubber can be good too, but I was meaning foam.
-
Any new subwoofer recomendations for 1801b?
-
Unfortunately, the SCC300 is gone :cry:.
My choice would be the TC1000, but this is only due to their excellent reputation and the high VAS of the TC1000. It looks good on paper, but I have never heard this particular driver.
http://www.tcsounds.com/tc1000.htm
Larger VAS/Cabinet subs will be more sensitive (or have deeper bass).
Alternately, I recommend you simply call TC sounds, describe your application and desires. They will recommend an appropriate driver.
Dave
-
Dave,
What do you think about using the Meniscus 8'' as a 3a way on a floorstander version of the 1801b? I thought about using it on a transmission line cabinet.
Regards,
Guilherme
-
I have mentioned previously that the 8" Meniscus is produces wonderful bass in a ported cabinet. My sentiment remains very true in this regard. And, the best part is the Meniscus 838 is not very expensive. I don't recall the exact Qts number for my drivers, but believe it was @ .40.
I believe that a TL or TQWP may sound marginally better than a ported cabinet, but the TL or TQWP cabinets are considerably larger. The size and mass of these cabinets is the primary reason folks don't implement them.
Dave
-
Dave,
Do you think that a sealed 1801b would be better in this case? What enclosure size do you recomend?
Guilherme
-
Do you think that a sealed 1801b would be better in this case? What enclosure size do you recommend?
It should be theoretically better, but the impact may not be audible. The sealed 1801b cabinet should be about 16 liters.
However, if you already have a larger 21 liter cabinet constructed, this will be fine too. Simply stuff the port with a sock. Prefer a good Champion sock, but I am certain that other brands will perform admirably too.
Dave
-
Do you think that a sealed 1801b would be better in this case? What enclosure size do you recommend?
It should be theoretically better, but the impact may not be audible. The sealed 1801b cabinet should be about 16 liters.
However, if you already have a larger 21 liter cabinet constructed, this will be fine too. Simply stuff the port with a sock. Prefer a good Champion sock, but I am certain that other brands will perform admirably too.
Dave
A silly comment. When I was at a famous designer's home, we experimented both ways. The "tightness" of a sealed cabinet was very obvious. So I ran with a sealed cabinet tho I was told I could go with a port, and could later stuff it with a sox if I changed my mind. Never looked back. I often test a speaker's bass with the Reference Recording's Fanfare for the Common Man track. If a speaker's bass performance is good, it would become very obvious when the drums come on, right at the head of the track. From my experience, a sealed cabinet still gives a far superior bass (in terms of tightness, at least in my case). Of course, one'd lose that 5-10 Hz below. I often thought hat most speakers are ported because of the intention to get that extra few Hz below. This is my personal user's experience, not meaning to challenge anyone's opinion. My hi-fi knowledge is limited. :thumb:
-
A silly comment.
I disagree. I think this comment is very good. Also, I must convey that your Reference Recordings sample track is a good choice. I have this recording, albeit on a Chesky label. The drum is very clear and easily discernable.
If I could design a perfect speaker, it would have a larger sealed woofer of good sensitivity. The theoretical dampening advantage of a .7qts (or lower) bass system is obvious and audible. However, for the 1801 the sealed version failed as as a stand alone monitor. Neither Dennis or I preferred this version - despite the theoretical advantages.
I believe this outcome is rooted in 2 possible variables. First, the sealed 1801 (and all sealed speakers), require more excursion in the bass region above the tuning frequency. The 1801 tuning frequency is 34hz. Folks often tout the problems with ported woofers when they unload, but this happens below (not above) the tuning frequency. Second, the 1801 lost 10-15hz of bass extension. Somewhere in these two possible variables, the 16 litre sealed 1801 lost in a/b comparison with the ported 1801 as a stand alone monitor.
However, Guilherme's proposition was for something in a 3-way application. With a filter circuit on the woofer, the impact of the ported versus sealed cabinet dissipates.
and
My hi-fi knowledge is limited
IMO, if you are listening to that music and making these discernments you have profoundly good hifi knowledge aa. Few folks have a mental memory firmly grounded the sound of live unamplified music. IMO, this is far more important than being able to recall all of the Stereopile Class "A" components, opamp slew-rates, vacuum tube compatibility, or schematic diagnosis.
Dave
-
I have finished a DIY subwoofer with two NHT10 woofers, parallel on a sealed enclosure.
I'll test it on my system using a active crossover, crossed at 80hz initially. After completing the adjustments of the subwoofer with the system, I'll test the 1801b sealed on the 22L enclosure, and then adding wood pieces until it reaches 16L. This test will take a few days and I'll be on a trip next week, so I will post my coments in a few weeks!
Thanks
Guilherme
-
My hunch is that you won't hear any impact when adding lumber to fill your current cabinet. However I do suggest experimentally adding some fiberglass insulation (sound absorption) to the midrange cabinet.
I look forward to your comments.
Dave
-
Dave,
I'm designing my floorstander with 1801b sealed + Meniscus 8" in transmission line, and I thought about inclining the baffle so the tweeter magnet will be in the sabe distance of the midbass baffle.
I have seen this in many speakers, is there any reason why you didn't use this method in your speaker? Plus, what do you think bevel the baffle?
I mean something like this:
(http://www.positive-feedback.com/Issue17/images/vr4a.jpg)
Thanks,
Guilherme
-
This is a good question.
Tilting the speaker backwards may make the crossover easier to design. This isn't always true, but seems that it is often true. Minimally, there is absolutely nothing wrong with a backwards leaning speaker.
I think the bevel looks nice. Certainly Avalon has marketed this appearance very effectively. However, the 1801 was designed with a flat baffle and a slightly rounded edge on solid lumber. The primary reason for the rounded edge or beveled edge is appearance. While there are theoretical advantages to larger roundovers, their audibility is very questionable. Aesthetics are the primary motivator IMO.
Off axis 90 degrees I heard surprisingly positive effectiveness from a completely round cabinet created by Wayne Wendel ( a local gent). I don't recall having heard this in other speakers. When moving off axis the sound quality of most speakers will decline notably. However, there are a few potentially mitigating concerns.
1. We didn't have the same drivers and optimized crossover in a rectangular cabinet for comparison.
2. Perhaps the extreme off axis signal from a loudspeaker doesn't matter or SHOULD be distorted? After all, folks go to great effort to absorb/disperse the in-room off axis reflected signal from a loudspeaker.
Dave
-
Dave,
So the 1801b crossover needs to be changed to use a inclined baffle?
Thanks for the reply
Guilherme
-
So the 1801b crossover needs to be changed to use a inclined baffle?
Yes.
Dave