Gravity Well Of A DarkStar

ooheadsoo · « **Reply #20 on:** 27 May 2005, 06:53 am »

Quote from: Dmason

Wow. Off and running. Good discussion. Nice to come home to...

- Rule of thumb, 10 per cent offset of baffle. Ill give all of you a head start. Whatever size chunk you start with, cut TWO baffles for each driver, and the "control" baffle, mount 29/29cm from upper inside corner, matched pairs. This is filter-down DarkStar technology to get you going, and is the product of testing between myself and another gravity well voyager in Germany.

JLM talks about reflections. Dead right. What I did was get some ...

Unless you are suggesting that the visaton driver is perfect, I was simply wondering how an obvious issue is being addressed - or do we throw away desire for accurate, if not precise, frequency response once we get into full range drivers? Obviously there's more than one way to skin a cat even when we restrict ourselves to the dipole or fullrange worlds. Not that I know any. Aiming the speakers at the knees...sounds good, maybe especially if you've got carpet.

mcgsxr · « **Reply #21 on:** 27 May 2005, 12:23 pm »

JLM - sorry to be the king of clarification, but the more I read about your idea, the more I have to understand it...! To that end, are you suggesting that the config you outline is to limit reflections from one baffle to another, or the driver from reflecting on the baffle that it is mounted on?

What you describe sounds like a good way to tame either, and in time, I might end up with something that complex, but for the near term, I intend to settle my own curiosity about this driver in an OB, simply by tossing it IN one, and listening. That will have me rapidly knowing, if this is worth investing more time and effort into tuning.

I have read a ton about these drivers (a certain measure of scepticism is indicative of intelligence... or am I now just spiralling off into self congratulation... hee hee

) and am personally unclear on how something that measures as it does, can perform SO admirably for SO many. Lots of people (around the globe to boot) have posted about OB joy with this driver. Some have gone to great lengths with digital equalization, others use complex Xovers and supertweeters, and others still dumpster dive for large panels, and bolt them in... most suggest that the end result is at least really good, and many wax eloquent!

For me, my approach to most things performance, has been the desire to have 80% of the best performance, for 10-20% of the entrance fee. ALL the bikes I built exuded this prioritization, often garnering remarks along the lines of "where is the rest of your bike...", but in the end, they all performed in a manner that always left me, and usually others, staggered.

That is what I am after here, so in the early stages at least, that means no digital eq, no extensive baffle design, no Xover of any kind. It strictly means a "wide range driver" (for those that are letter of the law folks for driver performance rating) in a large open baffle. Period. The way that sound does, or does not do it for me, within 24hrs (the set of drivers I have purchased are lightly used, so they are broken in already) will dictate how long I will live with them. I will experiment with toe in, and room placement, and listen.

My approach includes an interest in how things measure, in the end, if they don't do it for me, expect to read that. I call things as I see them, and don't have the extra $$ to keep toys around that do not enthrall me!

The 2 weeks until I receive the drivers should give me enough time to determine what baffle dimensions I will start with, and once the setup is in place, I will post pics of the nastiness (expect, as is my style..., the early shots to be bare wood, no finish etc).

Once others get their drivers, I expect to read about what they think, and hopefully, along the way, we can guide each other to places that we each find satisfactory.

Have a great day,

Dmason · « **Reply #22 on:** 27 May 2005, 01:00 pm »

I was not suggesting the driver was "perfect," far from it. My background is in the physical and health sciences. Perfect is not a word often used in my vocabulary....I was pointing out the fact that the Q factors of this driver played right into the hands of being extremely effective on open baffles. A Qts = .7 is as good as it gets, for open baffle, and lo and behold, the Visaton, which is getting slapped onto open baffles all over Europe. What makes it even mo betta is the fact that given its sound and build quality, it is a DEAL. The value here is outrageous, and qualifies handily as another ValueKing (tm) audio component.

"This one's juuuuuust right." -Goldilocks

Beyond that, I, and about everyone else who has bothered to not criticise this driver, but buy it, try it, has found some magic. It's musical presence is in my mind extraordinary. The potential for fun, good sound, and intellectual exploration is evident in the wildfire nature of this thread. I am very interested in what comes of it, and moreso in these people's impressions.

One of the neatest observations of open baffle listening has been that once one's ears are accustomed to this presentation, box speakers leave them wanting. The colorations produced by even the best of this approach is just staggering. I read of this phenomenon experienced by others, all the time. It is not subtle.

JoshK · « **Reply #23 on:** 27 May 2005, 06:29 pm »

Another option that is said to be good is Ciare CH250, which runs about $150 USD shipped to the US per pair. I just ordered a pair to try out, figuring why not at this little $$. I can always turn around and sell them if they don't work out.

I have a DEQX so I was thinking once I play around with them to see if I like them augmenting them with an OB sub & ribbon tweeter.

Dmason · « **Reply #24 on:** 27 May 2005, 06:44 pm »

For Ciare CH250 www.assistanceaudio.com Jack Arnott. The US Distributor.

I have the Ciares and they are great. they are the low cost alternative, but, they require contouring, and they are not "high end" quality. Kurt Chang got a pair from Assistance for $90/pr. The Visatons for the $ difference, are in another league altogether. They are powerful, very wide range speakers with uncommon presence. The Ciares are designed as car speakers. They are the King of car speakers.

-Richard- · « **Reply #25 on:** 27 May 2005, 07:53 pm »

Hi Mark (in Canada),

Great to have you experimenting with the B200's
in an OB design.

I for one applaud your sense of rigorousness and
your desire for ruthless pragmatism...it is important
that this project be approached with clarity and
precision...however, I hope you will have some fun
along the way as well...I certainly plan to...Dan has
been right every time I ever followed his sage advice...
and that heightens the fun factor for me...

Of course in audio there seems to be no common
ground that everyone can stand on...too many differences
in expectation and taste...how much "conditioning" plays
into our "preferences" for a particular quality of sound is
fascinating to consider...

And Dan's unusually intense experience with a vast
number of speakers he has lived with...some of which
he built himself...has given him an overview that is missing
from most of our own experiences...certainly mine...

It is like an author who has read hundreds of books...as
opposed to just a few...reading a novel he especially likes and
recommending it to others...his frame of reference has given
a depth to his insights that may not be immediately apparent to
the average reader...it would be similar for someone who has
seen a great many films for example...

I mention this because the "Shock of the New" (Robert Hughs)
needs a bit of time to absorb and understand within the context
that we have devised for ourselves...

In audio...as in most things in my life...I try to be fluid and open...
I reserve my real skepticism for the hyped, overblown, overmarketed,
overpriced junk that is passed off as the genuine...

I am excited to build the baffles and give a listen...and let's also
give other amps we may have around a chance to play on these
also...including any tube amps...

But I really like your no-nonsense approach...it echoes my own...
and please keep us informed about everything you learn and
discover along the way...including measurements and other
considerations...again, Mark, nice to have your presence in this
fascinating experiment...

Warm regards -Richard-

JLM · « **Reply #26 on:** 27 May 2005, 08:11 pm »

Mark,

Its gratifying that anyone listens to my little wisps of half way intelligent thought. What I was primarily after was reduction of reflected sound from say the left channel speaker bouncing off the right channel baffle (as they're relatively large).

I'd start with one 48 inch by 48 inch baffle and one 48 inch by 38 inch baffle. A/B the two in mono and take measurements (a Radio Shack spl meter and Stereophile CDs is less than $80 USD). If they sound the same or close cut the 48 x 38 down to 30 inch by 38 inch and repeat. Drop to 20 x 30 and repeat until you're satisfied with the size versus bass response trade-off. Don't forget to offset the driver on the baffle each time.

Later on you can play with hinged baffle wings, digital EQ, and absorptive materials.

Dmason · « **Reply #27 on:** 27 May 2005, 08:29 pm »

JLM

More than little wisps of wisdom....what makes this stuff interesting is that it is an unexplored frontier, for the most part. The only thing carved in stone is baffle roll off, all the rest is dependent upon which driver in what baffle, in which room, into whose ears.

I keep coming back to your idea of corner loaded baffles, unless I have misread this, the idea was to mount the baffles -->/\<-- onto the adjoining walls, in corners? If so, this is something entirely new, as far as I know, and with respect to the corner walls-as-baffles, represents a sort of "free lunch" approach. Is this what you had in mind, or were you referring to placing baffles ~in the corner? If this actually worked, you could get a vertically loaded, ceiling vented configuration, where bass could propagate along the ceiling freely, (not alot of furniture on the ceiling) and then propagate along the floor. this to me is the most interesting idea yet. Rounded, cork covered corners would look good in alot of dens.

JeffB · « **Reply #28 on:** 27 May 2005, 09:42 pm »

Dmason,

Do you know the difference between the Behringer DEQ 2496 and the DCX 2496. I know this is not an easy question as the products do so much, but I am hoping for a relatively simple answer.
The DEQ looks like an equalizer, but the DCX looks like a cross-over plus an equalizer. Thus it looks like the DCX may do everything the DEQ does and more. But I have found the DCX for $250 and the DEQ for $227(Edit, this price is a mistake. $299 is more like it). Am I missing something? Does the DCX give up something in the equalization department to the DEQ.

After writing the above, I did a little more looking. The DCX has only analog outputs. The DEQ has an S/PDIF in an S/PDIF out. Can the DEQ take digital in, process it, and output digital, without ever converting to analog?

tianguis · « **Reply #29 on:** 27 May 2005, 09:49 pm »

Dan:
I, too, like JLM's OB approach. The Visaton site has info on a corner cabinet which tames the rising FR of the driver, although it reduces the eficiency considerably.

Regards,
Larry Welsh

Dmason · « **Reply #30 on:** 27 May 2005, 10:15 pm »

Larry,

The EckBox is very cool indeed, the best design on the Visaton website, and would be great for corners, but it is a sealed unit, with some heavy ceramic weather in its forecast. That load though is what I was reminded of, instead, I am wondering what JLM is thinking about one panel ~5' or more, with a ceiling "vent" of >12-24 inches, and perhaps the same on the floor or run the baffle TO the floor to take advantage of the "doubling" effect. The baffle "sees" an infinite baffle on three sides, a free lunch...

The B200 is capable of making plenty of bass, add ceiling propagation, and use digital contouring, there is no doubt in my mind it would work.

Digital contouring would allow it to retain its excellent 97db SPL, and one would be able to tune the load to the room. Sealed bipole subs into one unit in the middle used as a table base. This is one idea.

The Behringer DEQ is special because it can operate entirely in digital, and has been proven to do no harm to the signal. If the DCX could do this, it would be goodbye forever to crossovers. Once you have used one of these, and have been able to sweep the crossover frequencies in real time, alter phase and time align, and maintain an active coupled relationship between the amp and driver, there is no going back.

Passive crossovers are sonic suicide. They completely kill the sound such that you can never really hear how your speakers are transducing your source sound, ie: how The Music actually sounds. Turns out there is ALOT of info on CD's, including all the emotion and ensemble interaction the artists intended. Once you hear this difference, there is no going back. Once people become openly baffled, seldom do they come back to box speakers. I have noticed this Conversion on the Road To Audionic Damascus discussed many times on other audio threads.

tyee · « **Reply #31 on:** 27 May 2005, 11:23 pm »

JeffB
Where did you find the DEQ2496 for $227

tyee

JeffB · « **Reply #32 on:** 28 May 2005, 02:28 am »

tyee,

I was in a hurry to find a rough estimate of price.
I put the following query in google:
behringer deq 2496 price

The 4th hit read as follows:
Behringer DEQ2496 Ultra Curve Pro, just $ 229.95
http://www.musiciansnews.com/recording/49/behringer_deq2496_ultra_curve_pro.shtml

I goofed by $2 in my post, as I was in a hurry.

Upon further investigation though, this turns out to be blemished used model from zZounds.com.

Sorry, for the mistake. New it is $299.95 from zZounds.com.
I have never bought from zZounds.com.

ooheadsoo · « **Reply #33 on:** 28 May 2005, 05:35 am »

Here's the yahoo group dedicated to modding the behringer dcx. Clearly they think that improvements can be made. http://login.yahoo.com/config/login?.intl=us&.src=ygrp&.done=http%3a//groups.yahoo.com%2Fgroup%2FThunderstone_technical%2Ffiles%2FTL%2520Circuits%2FUltracurve%2F

How do you guys think the visaton compares to the more standard fostex selection?

Dmason · « **Reply #34 on:** 28 May 2005, 06:34 am »

The single greatest difference with the Visaton in my mind is the fact that it can be well implemented on open baffles, as well as sealed and ported loads. Sonically, it is different. Warm yet analytical, just extremely synergistic with T amp sound. Highly sensitive, it benefits from the low noise of battery power.

The one Fostex driver I would say has the most in common with it would be the FE168ESigma, in my opinion, this clear, sweet midrange, non fatiguing, yet very direct dynamic sound, very good for intent listening. The 108 and 168 Sigmas to me are by far and away the most musical drivers Fostex makes IMHO. I prefer the B200 to them both.

powerbench · « **Reply #35 on:** 28 May 2005, 06:47 pm »

Do you have any plans or links to them,thanks.....in advance...

mcgsxr · « **Reply #36 on:** 28 May 2005, 07:41 pm »

Powerbench - the idea being tossed around here is called an open baffle - quite simply mounting one Visaton b200 driver in a board. The size of the board is variable - people run them in lots of differing sizes, but from what I read, many come to around 4 feet in H, and 3 feet in W for manageability reasons/workable compromises.

The drivers can be had in Canada from our French friends at http://www.solen.ca/.

The homesite for the b200 is here http://www.visaton.com/english/artikel/art_771_1_3.html.

Threads about these drivers are out there on the net, get using google, and try over at diyaudio, audioasylum etc for people's experiences.

I hope that I am able to have a set of these up and running one of the times that you will be able to come down to my end of the province, and we can try the Clari-T on them. I will be running them with my Bolder Teac, and would love to rub those two amps against each other (hey, keep it clean!

) using the same system, in the same room...

Oh, and Richard - I know that I am posting about how resolute I am about keeping the recipe simple, but trust me, I will be having fun with it too! I look very much forward to getting started on this project - now, if the boys I paid for the drivers would confirm that they have shipped...

powerbench · « **Reply #37 on:** 28 May 2005, 08:39 pm »

I like the idea of open board and baffle might be something to play with for a second systems ,ttyl....

JLM · « **Reply #38 on:** 28 May 2005, 09:54 pm »

Dan/Larry,

Third try to respond to this thread

(First two wouldn't "take"???)

Yes, what I was thinking of was a 16 inch by 72 inch baffle mounted to the walls of two adjoining corners with openings top and bottom. Baffle width based on clearances for driver and absorptive material along walls behind baffle. This would be a cross between pipes, infinite baffle, and open baffle.

Don't know if it would be a good idea, but it might improve DAF (domestic acceptance factor).

I'm unaware of Fostex making an extended range driver with Qts of 0.5 (the minimum to provide decent quantities of bass by most folks measure).

Dan,

How would you compare the B200 to my Fostex F200A?

Dmason · « **Reply #39 on:** 29 May 2005, 12:49 am »

I discussed the idea of a corner loaded hybrid IB/OB/Pipe with someone who has years and years of audio products development, going back to the Northridge salad days of Altec and its Tannoy wing, and his opinion is that it would work very well, as long as the baffle were extended to, and tied to the floor. He thought a healthy opening to the ceiling would be best, around 24" giving enough room to install a triangular waveguide. He elaborated that it would be cool to extend the wall sides up to include the waveguide, making it a unitized construction.

The Visaton is going to be modelled for a large TQWT as well. A LARGE, very high performance one with vertical, ceiling venting.

The B200 and F200A are different animals. One is a true high sensitivity wide ranger, the other is not. The Fostex comes as close to being a true FULL range driver as is out there, bested only by the Hartley 220MSG. The Fostex, to me sounds abit hotter, due to the metal dustcap, yet the Visaton extends higher, is greatly more sensitive, requiring 1/3 the power for a given SPL, and has cracking dynamics, a very organic, almost "lyrical" tone and unreal PRESENCE. The Fostex needs some real muscle to come alive, the Visaton turns the ClariT into a muscle amp. The B200/ClariT are capable of lightspeed reproduction, together.