[Christof]

I can take it no longer, it's time for another speaker build.  Rather than go the easy route and purchase one of Ricks kit's I'd like to throw a design objective out on the table as study of sorts and see what happens.  The objective is a 3-way box speaker using proven drivers with passive xo which satisfies the following requirements. 

1. This design should be more edgy than laid back, live sounding and accurate, it should do nothing to help the quality of recorded material.   
2. Tweeter should be live sounding but not excessive like beaming bright lights. 
3. Area between midrange and bass (80-120Hz) should have authority and not be an area just trying to "keep up" with the midrange and bass drivers.  The kick drum, for example, should be felt and be equal with the overall live sound of the speaker. 
4. This speaker should be capable of playing at high SPL but not require high SPL's to sound alive. 
5. Sensitivity is not crucial in this design but upper 80's should be a target. 
6. Biampable
7. Subwoofer design is possible but upper bass performance and integration with other speakers should be excellent.  Again this is a passive design.
8. Expected driver budget is $1K-$1200.
9. Crossover components should not exceed $500.
10. Rick will have the final say as designer but this speaker design should not necessarily follow the status quo ante.
11. Capable of mid to low 20Hz range in room.

Let the study begin everyone feel free to participate

Bingenito, in an earlier conversation suggested:

Large WWmtm:
2: Peerless HDS tweeters
4: Seas Nextel W15LY
4: Seas L26 (4 cu ft total. sealed alignment F3 at 39Hz and slow roll off F10 around 25. In room will be even better!)

Rick:
7" MTM (Excel woofers / HDS tweeter) with a single side-firing woofer

[Christof]

A couple considerations.....

Entering into the paper vs. metal debate......Nextel vs. Mag cone w18 drivers?
 
Dual, front baffle mounted L26's staying as a true 3-way or side firing 10"-12" driver as a 2-way with sub?  Can a integrated sub sound just as good when going passive?

[Bingenito]

Not to add on another question but is there some reason for limiting the speaker width? It appears that once you exceed an 8.75" woofer you go to the side....

[Christof]

If the driver is used strictly in the nondirectional freq range can you tell a difference b/t front vs. side?

What about bass drivers that work in both directional and nondirectional range?  They too can be found in side firing configurations of many designs, not necessarily Ricks but they do exist. One design using side firing 6.8" Extremis drivers comes to mind.

In the design I'm proposing above, I would not mind front firing L26's.

Rick?

[bpape]

Side firing woofers IMO are an issue in room.  They tend to create large FR swings due to direct cancellation from the side walls unless you have a very wide room.  Many vendors use this design.  I've had to work around more than one of them when trying to get a speaker to integrate into a room properly. 

One wouldn't think the SBIR would be any worse than with a front firing driver but based on my personal experience, they're much harder to get to integrate correctly - especially if you have less than 6' or so from the side of the cabinet to the side wall.  Also, when mounting them on the sides, you're automatically putting the woofer center closer to the wall - and significantly - with the front baffle the same distance from the wall.  Facing them toward each other is just a different set of issues.

I'm sure others will disagree - just my opinion based on dealing with many different types over the years.  I can't remember a single time dealing with a side woofer speaker in a room < 25' wide that we didnt' have isssues.

Bryan

[Jason1]

Dual SS 21W/8554 8"
woofers ported at 25hz

SS 13M/8636 4.5" mid

Seas 22TAF/G 3/4" alloy dome.

[JoshK]

I am thinking that the Top o the line 3 way that benginito has is a good format for this with less costly drivers.   My rec would be the Seas H1212 given your penchant for detail and clarity without harshness as I take your words to mean.  Then the mid could be an MTM of the Dayton RS 180's or the Seas L18s. The woofers could be either the Dayton RS270's or the Seas L26, but I'd go for two in each speaker.

These speakers would be relatively large, but they wouldn't be as SPL limited as one mid/ one woofer each would be.  XO becomes a bit more expensive with this combo, but I still think it is doable on your budget.  There is a DIY example of this combo that exists and many have commented on just how good it is.  My line of thinking is precisely the same line of thinking that led the previous DIY'ers to come up with this combo.  I think Rick is very comfortable working with these drivers too and has experience with them and I am 100% confident that he could create a wonderful, near reference level, speaker from the format. 

FWIW, I like Jason's rec'n with the exception of the mid.  In his example I'd personally opt for the Peerless HDS Exclusive 5.5" 882something.  It doesn't suffer the mid range impedance discontinuity the SS does (that suggests cone break up) that gives rise to a dip in response and corresponding rise in FR above impedance blip. 

[LadyDog]

Chris,
Sounds like you have quite a few good ideas already.  Here are a few I was talking w/Rick about.  All mtm designs with dual woofers.

8545 / Nextel / Crescendo

8545 / Accuton / Crescendo

The other thing I was considering was having the Aircirc or HDS substitute for the tweeter.

All may put you just above your budget though.

Best of luck.

Regards,
Jeff

[David Ellis]

My rec would be the Seas H1212 given your penchant for detail and clarity without harshness as I take your words to mean.

I fully agree with this advice  .

Also, this will work very well too:

sealed alignment F3 at 39Hz and slow roll off F10 around 25. In room will be even better!)

Dave

[Christof]

....The other thing I was considering was having the Aircirc or HDS substitute for the tweeter.

All may put you just above your budget though.

Best of luck.

Regards,
Jeff

I am interested to know the sonic differences between the AirCir and the HDS tweeters.  The larger dome size of both tweeters hopefully would not lead to a beaming effect, which is what I'm trying to avoid.  Unless the AirCirc has some magic to it, I don't think it is justifiable to spend 4x the price of HDS?   But then again one could say the same with RS drivers vs. Excel drivers.

...My rec would be the Seas H1212 given your penchant for detail and clarity without harshness as I take your words to mean.  Then the mid could be an MTM of the Dayton RS 180's or the Seas L18s. The woofers could be either the Dayton RS270's or the Seas L26, but I'd go for two in each speaker....

Josh, what would be your reasoning to use metal in the mids vs. the Nextel W15LY?

I think it is now established that the LF will be handled by dual L26's in a front firing config.  The enclosure will be sealed.  The upper MTM portion of this design is yet to be determined but I like the idea of the HDS tweeter, Rick is familiar with it and certainly it falls within the budget demands.  I am, however, still looking for reason(s) not to use the HDS tweeter.  It may be important however to first establish the mid drivers.  To get around the nasty oil can upper response of the L26 I think it will be important to cross the mids fairly low but I must stop here and remind myself that the XO will be Ricks job entirely. 

The sole purpose of this study is to find a combination of 3-5 drivers, using the input of many people, in a sort of think-tank, then carefully narrow the selection down and hand the group of drivers over to Rick.  This study is in no way intended to raise questions about Ricks ability to select drivers.  He has demonstrated his ability over and over again.  If anything this study will demonstrate Rick's ability to adapt his design genius.  I really appreciate everyones input and Rick's willingness to tolerate such madness:thumb:

Lets discuss mids, since I feel that this is probably the area that I will be most critical.  I want to feel the mids.  Simply hearing the "chop" of David Grisman's mandolin or a rim shot from Billy Martin is not enough, I want to feel it.  The sound and feel of stringed instruments is THE most important thing to me.  Perhapse the mids will consume a better part of the driver budget?

What will it be, Nextel W15LY, W15EX's, RS180's......

Thanks again, everyone, for chiming in on this thread.
-c.

[JoshK]

Christof,

Here is *my* thinking.... take it for what's its worth.  I have done some thinking along these lines in my own speaker building pursuit considering many of the same drivers and have spoken with many who know much more than I about them.  So my opinion is the culmination of these things.

Peerless HDS - It looks to be a great tweeter, but, when compared to the H1212 leaves one wondering.  The H1212 has flatter response, comparable or lower distortion everywhere and is cheaper.  So then why the HDS?  The Aircirc on the other hand, looks like it really does deliver in initial testing, more needs to be done when they actually start shipping. 

The impact, rim shots, transients and other things you mentioned are actually reproduced by the tweeter, not the bass or mid.  When you think about it, even a fast drum slap's leading edge is a high frequency affair.  Fast transients are sharp edges, which is the high frequency portion of the wave and thus gets reproduced by the tweeter.  This is why tweeters are important and why it is necessary to have low distortion in the tweeter.

The midrange is very important though.  The more pistonic the midrange is, the more likely it will maintain a flatter response in band and maintain lower distortion, all else being equal.  Metal cones generally make for more pistonic behavior, the exception being the peerless exclusive paper/nomex drivers of 5.5" or smaller **.  However, the price is the steeper slopes needed or traps coupled to shallower slopes, either way the complexity and parts count goes up in the xo.  Given what I've heard with Jon Marsh's 8th order CE filter xo's, the burden of proof is on the other camp that shallow slopes sound better as I've never heard this to be the case, but I haven't heard Dennis Murphy's designs.  Steeper slopes generally mean you can play louder cleaner (back to the spl criteria) if the xo points are in the realm where the drivers can handle. 

The Dayton RS mids are just super high bang for the buck.  They aren't the end all be all SOTA driver though.  Just when comparing a large lot of what is out there, very few of the expensive drivers deliver better performance, so only some are worth paying more for, again IMO.  The SEAS Mag Excel's are in that short list, the Nextel's don't look to be there. 

The Nextel's distortion figures really aren't that impressive given the price.  We can each read the tests and come to our own conclusions on some of ranking, but the Nextel's don't seem to add anything to the table above say the Peerless Exclusives other than easier breakup leading to a simpler xo....personally I don't think that is a fair trade, others may differ. 

If you want to spend the lion's share of the budget on the mid, that isn't a bad thing, but I'd look to those that deliver more than just cool factor or aesthetic appeal.  Dayton RS, SEAS Mag Excels, Accuton (think big $$$), Peerless HDS Exclusives, Vifa XG18 (tenatively), etc. 
I'd probably consider the Seas W18, the RS180 & the HDS 5.5", but probably lean towards the W18 depending on where Rick wants to cross to the L26's. 


** there seems to be some question with newer Exclusives of the 7" & 8" size, where changes have been made and results are not as pretty.  There is a thread going on on htguide.com from some of the driver testers about this. 

[MarkM]

Christof,

I see you are moving forward in the design, quick question if you don't mind.

When you owned the Chalcedony, did you have a problem integrating the side mounted subs with your room?

I like the sleek profile of the MTM with side mounted woofers, guess the problem is where the xo point is for integration.

Joe D has done this recently @ Snell acoustics, http://www.snellacoustics.com/ProductDetails/3424.asp.

In the MTM with side firing woofer, were those Whomps proposed?

Thanks

[Bingenito]

Josh,

Great write up!

I would like to add my own "personal" opinion to what you mentioned regarding the Nextel drivers or any drivers for that matter. Distorsion measurements are a good indicator of a drivers performance but certainly not the only factor to look at when selecting a driver for a particular project. In the end the sound is the deciding factor based on the design goals and what the client or designer is looking to achieve.

Having owned several Seas Excel based systems I opted for the Seas Excel Nextels for a slightly fuller, warmer presentation then the Mag cones. Is there more measureable distorsion?.. maybe but they provide the exact sound that I was after so the design objective was met. If distorsion was all bad people would not be using tube gear.

Just my perspective

Bryan

[Christof]

Christof,


When you owned the Chalcedony, did you have a problem integrating the side mounted subs with your room?

I like the sleek profile of the MTM with side mounted woofers, guess the problem is where the xo point is for integration.

Mark

In the listening area (living room) of my last home I had horrible bass problems which I do not attribute to the Chalcedony design.  I have learned a great deal since I first built the Chalcedonys and I now feel that I could have done a lot to correct bass issues in my room.  I do wish I would have gotten the chance to try them in a different room for comparison.  I did find it a little tricky to get the subs adjusted just right.  Infact, I never really found that "just right" spot but again I attribute that to my room and my lack of understanding of the BIG picture. 

From what I've gathered there are people who are against side firing woofers and people who don't care either way.  The people who like the side firing, it seems, usually are making the choice for aesthetic reasons.  The other camp have argument against side firing because of integration and other issues.  See Bpape's post:

I'm sure others will disagree - just my opinion based on dealing with many different types over the years.  I can't remember a single time dealing with a side woofer speaker in a room < 25' wide that we didnt' have isssues.

Josh & Bingenito you have given me(us) food for thought.  This is the kind of input that will make this design shine

As it stands L26's are a given.  Nextel vs. metal for the mids and as I stand corrected by Josh about the transients, which are in indeed in the tweeter territory, I need a tweeter which will not let me down will it be HDS, 1212, ???......

[Rick Craig]

Side firing woofers IMO are an issue in room.  They tend to create large FR swings due to direct cancellation from the side walls unless you have a very wide room.  Many vendors use this design.  I've had to work around more than one of them when trying to get a speaker to integrate into a room properly. 

One wouldn't think the SBIR would be any worse than with a front firing driver but based on my personal experience, they're much harder to get to integrate correctly - especially if you have less than 6' or so from the side of the cabinet to the side wall.  Also, when mounting them on the sides, you're automatically putting the woofer center closer to the wall - and significantly - with the front baffle the same distance from the wall.  Facing them toward each other is just a different set of issues.

I'm sure others will disagree - just my opinion based on dealing with many different types over the years.  I can't remember a single time dealing with a side woofer speaker in a room < 25' wide that we didnt' have isssues.

Bryan

Actually I've had the opposite experience. The key is to load the woofer near the floor so that you get good boundary reinforcement. When you place them higher up then the room becomes more of a factor. The active subwoofer systems I prefer (like the RC4) also provide a parametric EQ for good integration with the room.

[JoshK]

I just noticed that my suggestion was damn close to Rick's Peridot.  I hadn't look at his offerings in a little while so I hadn't noticed the similarity.  Replace the ribbon tweeter with the H1212 and you have a slightly smaller format of what I described. 

I of course think you should ask Rick his opinions too, as he has far more experience then I* or others here.  He might suggest something a bit different based on his experience with how it all fits together.

* I am just the armchair speaker designer, as I haven't designed anything really yet (in the process but haven't finished).  I am just going based on what I've learned and read.   

[JoshK]

Josh,

Great write up!

Thanks, just trying to be helpful.

I would like to add my own "personal" opinion to what you mentioned regarding the Nextel drivers or any drivers for that matter. Distorsion measurements are a good indicator of a drivers performance but certainly not the only factor to look at when selecting a driver for a particular project. In the end the sound is the deciding factor based on the design goals and what the client or designer is looking to achieve.

I do agree.  I also think that a lot of good measurements help guide you to designing good sounding speakers.  One may disagree, but I think they go hand in hand. 

Having owned several Seas Excel based systems I opted for the Seas Excel Nextels for a slightly fuller, warmer presentation then the Mag cones. Is there more measureable distorsion?.. maybe but they provide the exact sound that I was after so the design objective was met. If distorsion was all bad people would not be using tube gear.

I think that 2nd order distortion in small amounts can be a very good thing.  My other hobby has been researching and designing (not yet building so much) tube gear.  I think the orders of magnitude are a little different though.  Generally speaking speakers make much more distortion than gear, and getting the overall speaker system distortion down leads to more transparency in your system.  I still like to see a nice profile of HD and prefer to see 3rd lower than 2nd and very little higher orders.  Certainly the Nextel has a bit more 2nd than the Mags do, which is nice and can hide some warts due to the masking affect. 

My concern with the Nextel wasn't so much the 2nd but the rising distortion at the top end, although I'd have to look back at this.  It could very well never present itself as a problem depending on where your system is crossed and how. 

[Christof]

Josh

I just noticed that my suggestion was damn close to Rick's Peridot.  I hadn't look at his offerings in a little while so I hadn't noticed the similarity.  Replace the ribbon tweeter with the H1212 and you have a slightly smaller format of what I described. 

I think this goes to show.....

I of course think you should ask Rick his opinions too, as he has far more experience then I* or others here.  He might suggest something a bit different based on his experience with how it all fits together.

Rick's opinion certainly matters here and he will have the final say.  I started this thread intentionally to get the opinion of many people, hoping other designers would chime in as well.  While Rick has not given much input on this thread, he has given me much input through PM, e-mail & phone.  We have discussed so much that at this point he's probably wondering if I'm really going to fork over some cash for this new design   I twill happen, Rick.

I think that in the world of design, a good designer of any sort is able and willing to adapt and Rick has demonstrated this time and time again.  I want this design to push Rick a little and I think my request may very well do just that.

Enter the next design specification:

BOX GEOMETERY:

How about individual boxes for tweeter, mids and bass drivers, similar to these Art Loudspeakers.  This design specification is not intended to effect driver choice, though it may have some importance.

[MarkM]

Enter the next design specification:

Individual boxes for tweeter, mids and bass drivers, similar to these Art Loudspeakers.  This design specification is not intended to effect driver choice but it may have some importance.

Wow, seperate boxes will make for a William "The Refrigerator" Perry size speaker. 

[Christof]

Wow, seperate boxes will make for a William "The Refrigerator" Perry size speaker. 

MarkM

Very good point here.  I wounder if the fact that the individual boxes could all be constructed independently with CLD would outweigh the drawback of the extreme size. Enjoy the game tomorrow