[Bingenito]

JLM,

Buddy be happy with your full range Fostex. No one here is trying to take them from you.

They do not float my boat but I am glad that you have found happiness.

Now excuse me while I go take my brain washed self downstairs to listen to some real speakers

Enjoy!

[John Ashman]

Full range sound? My Fostex F200A based speakers do 30 - 20,000 Hz in room, which bests most multiple driver designs I know of.

+/- what?  It can't do it flat, I can assure you.  Can you point me to a professional, unbiased measurement on that?  

Lack of driver resonances? Isn't resonances from a single high quality driver this better than cheaper multiple drivers plus crossover that can't integrate as well as a single driver?

Nope.  There is no substitute for cherry-picking the best part of a drivers response.  You're simply trading one distortion for another.  The goal of DEQX is to eliminate or reduce to inaudibility both cone and crossover distortions.  

Low distortion? Is this better than mixing drivers across a baffle? How much distortion is there at 80 dB (typical audiophile output levels)? A line array or field of drivers cannot image.

The distortion above and below your drivers best areas would be significantly higher.  I can assure you that a point source like Xd with it's two drivers can image quite well and provide substantially lower distortion than a single driver.  

Good dispersion? Please define "good" dispersion. Wide dispersion causes reflections from side walls/floor/ceiling that interferes with imaging. Narrow dispersion can be aimed to adjust response.

It also makes the sound realistic and gives you both a soundstage and a good sweetspot.  Good dispersion is defined as something that is symmetrical at all frequencies.  Something that doesn't beam.  Your Fostex will begin to beam around 2000Hz energizing the room differently above and below that threshold.  That doesn't sound natural and prevents you from having a wide sweetspot as well.

All the OTHER things you get since one driver can't do it all? My speakers reach 103 dB continous and 109 dB peaks in a 2,000 cu. ft. (12 x 20 x 8)room. The 80 - 8000 Hz range is covers the essential musical range and more than covers the all important midrange. This is where single extended (full) range drivers live and thrive. Marketing hype has brainwashed the majority into believing that 20 - 20,000 Hz response at 120 dB with wide dispersion is needed..........

Now you're just rationalizing.  If a single driver could do it all, we'd all own them.  I'm not trying to pick on you, but you're doing something akin to walking into a church and screaming "there is no god, you're all doomed".  Well, in this case, DEQX is real, it works and allows you to have what you like in a speaker and all the things you don't know you're missing as well.  The single driver group is a subset of a subset of a subset.  Now, the question is, do you want to understand it or argue about it?   Because you're outgunned and outnumbered.

[Bingenito]

What he said  

[Rick Craig]

Rick,

I doubt we disagree--I suspect 36dB to 48 dB/octave is plenty for even a worst case scenario. I only mentioned 96 as this is the minimum slope available for 2 of the 3 XO's and was the choice of the DEQX designers.

The other filter set normally used for sub integration offers butterworth and L-R alignments as well as minimal phase, all of much lower order.

Thanks for the clarification.

[mac]

http://www.audiocircle.com/index.php?topic=15848.msg138510#138510


Linear-Phase:



Linkwitz-Riley:



Butterworth:

[mcgsxr]

I find it interesting every time differing camps of audio get excited and start thrusting back and forth.

The funny part is that both are simply trying to share in the happiness that they each have found.

I have no doubt that some exceptional results can be obtained via this new digital technology for building speakers.

I also have no doubt that some exceptional results can be obtained via single driver speakers - at present I am loving the cheap set that I built!

Glad to see that people are passionate about this, now, on with the fun!

[John Ashman]

I think the one good thing about DEQX is that it *almost* brings all the various "isms" as my dad would say, under one tent.  It has something for single driver lovers, horn lovers, ribbon lovers, cone lovers, etc.  I think the only people who are skeptical are analog folk, but I do believe that is without reason.  The advantages outweigh the disadvantages by a huge amount.  DEQX is one technology that, I think, proves that one not need fear digital.  AD and DA conversions are so good these days that they can be argued to be objectively and subjectively transparent, so much of the fear of this technology is just that.  One person was arguing that it was a disservice to run his pure vinyl system through an AD/DA conversion, but I argued "hey, but you're willing to send your precious vinyl through a bunch of capacitors, inductors and resistors that destroy phase and time as though that has no effect because it's 'analog'?"   All distortion is bad, trying to say that one is better or worse than the other smacks of dogmatic religion.  If I were a vinyl guy, I'd be glad to liberate my records from the distortion of an analog crossover.  As I said to another person "vinyl doesn't sound like vinyl because it hasn't ever been digital, it sounds like that because it's a small needle vibrating on a disc".

Heck DEQX will even let you use tube amps.  How cool is that?

[Rick Craig]

Thu Mar 03, 2005 6:44 pm    

--------------------------------------------------------------------------------
 
Rick Craig wrote:
One area I would disagree with you on. There was a controlled study done on the audibility of driver breakups and these steep 96+ db/octave slopes really aren't needed. I don't remember the exact AES preprint number but I believe Sean Olive was the author.


Rick, I don't know the specifics of that study, but I find driver breakups of metal drivers to be extremely audibly. Every passive, metal cone speaker I've ever heard, except for the Genesis titanium midrange models has exhibited them often to the point of being unlistenable. The worst was Velodyne's D661. AWFUL. I couldn't listen to it for more than 60 seconds. Genesis dropped the 4" titanium cone mid (which is small enough, rigid enough and crossover steep enough in that app to be problem free) from its APM2 speaker and the sound, with dual 6" aluminum cones was bright, yet lacking in detail and the imaging was poor. I couldn't figure out the problem until I read up on breakup modes and then it made sense. It never sold well and was almost discontinued by the time it made it to market. I had a customer bring by Axiom M80s. They just about ripped my ears off and became fatiguing within minutes - he sent them back and bought poly-equipped NHTs. But most people think Axioms are "detailed" rather than bright. And don't get my started on Kevlar and B&W, I can't even believe people like them at all. "it's like they're TOO detailed". Like there is such a thing. That's what you call breakup modes in action.

You can try to notch out the breakup, but I suspect that doesn't work well at all volume ranges from what I've read and, of course, you add other problems with notch filters, so it is a bandaid at best. The best way to deal with it is to crossover steeply enough that they are never an issue at all and there is no energy reaching the driver by that frequency. Even if it weren't audible, there's no real downside to eliminating them, at least with a device such as DEQX. I confess to not having heard the SEAS Excel without DEQX, but it sounds fantastic with it. NHT insists that they couldn't use the Excel without DEQX because the sound would be unacceptable, so it won't find its way into any of their passive designs. NHT uses a 2000Hz, 110dB/octave crossover, partially to avoid the ringing at ~4800Hz and partially to preserve dispersion. I suspect that DEQX on the big Selahs would simply make the speaker smoother and more refined, though, with that many drivers, the cone resonances would probably relatively small.

Speaking of dispersion, Rick, is it an actual fact or wive's tale that line arrays actually increase horizontal dispersion? I was arguing this, but then it appears that one of your white papers you posted seems to indicate something else.
 

Actually John there are several good designs (Selah Audio, Ellis Audio, Joseph Audio, Salk) available with passive crossovers that use the Seas Excel magnesium cone drivers.  I would hardly call any of them unacceptable  

The resonances are linear distortions so regardless of whether you have a simple 2-way or line array with multiple drivers they still will be present. Once you suppress them beyond the threshold of audibility then any steeper slope isn't needed (but as you note with a digital crossover the greater slopes won't hurt but there isn't any additional benefit).

Line arrays have a cylindrical wavefront so the horizontal coverage is much broader than that of a point source speaker. The extent of the coverage still depends on the same aspects that affect a point source - lobing, driver directivity, and crossover execution.

Rick

[ted_b]

I think the one good thing about DEQX is that it *almost* brings all the various "isms" as my dad would say, under one tent.  It has something for single driver lovers, horn lovers, ribbon lovers, cone lovers, etc.  I think the only people who are skeptical are analog folk, but I do believe that is without reason.  The advantages outweigh the disadvantages by a huge amount.  DEQX is one technology that, I think, proves that one not need fear digital.  AD and DA conversions are so good these days that they c ...

Now c'mon John, you can't argue that for $3k you get State-of-the-art room and speaker correction (which you do) AND get SOA DAC and AD conversion (which you don't..heck most of that cost significantly more than $3k+ in decent outboard boxes).  Running vinyl or any other analog through an addtl ad/da, especially as middle-of-the-road as DEQX's is, can raise some fear from analogers out there.  Overkill states it very clearly in their product direction; they're ripping out the dacs.

All I'm saying is that let's not set the DEQX up to be a panacea for all ills.  It seems to clearly be the best set of code for FIR filters, crossovers and driver correction that's out there.  Add that to a decent preamp/switcher and remote, and you've got one hell of a bargain for DIY'ers and others at $3k.  To say that it overrides all other tradeoffs and all other decisions in the signal path....well, I, for one, know it didn't in my case.

Ted

[Bingenito]

Ted_B

Holly crap, your room is killer

[JLM]

John,

I might be out numbered, but I've tried it both ways, having owned several multiple driver speakers and listened to many single driver speakers.  Have you?  Right now I'm listening to piano and it sounds so good!

All I'm trying to say is that the need for/advantages of fancy crossovers, woofers, and tweeters is far more exagerated than most would believe compared to a well executed single driver speaker because they've never heard one.  Is it rational to justify one approach or condemn another without evidence?

Being in the "mainstream" does not automatically make one right or best.  Not wanting to pick a fight, just enlighten as to the possibilities of a simplier the better philosophy.  I don't want to make you more defensive, so I'll let this issue here go.  I wish you well.

[doug s.]

Ted_B

Holly crap, your room is killer

yes, wery nice indeed.  but one thing you can do, imo, for a big improvement - this topic yust came up in another thread re: florian's new rm30's - make the coffee table go away!  

doug s.

[John Ashman]

Actually John there are several good designs (Selah Audio, Ellis Audio, Joseph Audio, Salk) available with passive crossovers that use the Seas Excel magnesium cone drivers. I would hardly call any of them unacceptable  

Unfortunately, I haven't heard them, but I've just had bad experiences, at least with aluminum mids, but you have to admit that the peak on the W15 is pretty wicked!  

The resonances are linear distortions so regardless of whether you have a simple 2-way or line array with multiple drivers they still will be present.

Gotcha.  I wasn't sure if it was linear or whether they got worse with the volume.  I 've just noticed that kevlar, for instance, is okay at low volumes, but......

Line arrays have a cylindrical wavefront so the horizontal coverage is much broader than that of a point source speaker. The extent of the coverage still depends on the same aspects that affect a point source - lobing, driver directivity, and crossover execution.

So, for the same driver/tweeter, will a line array have a truly wider dispersion or just a narrowed vertical dispersion.  If so, do you know why that is?

[John Ashman]

I might be out numbered, but I've tried it both ways, having owned several multiple driver speakers and listened to many single driver speakers. Have you?

I've heard single driver systems and while the midrange is often very good, the treble has always been unacceptable (especially for a drummer) and the bass wasn't there.  But have you heard a proper DEQX system?  It has the coherency of a single driver system, but has things your speakers could never dream of having.  

All I'm trying to say is that the need for/advantages of fancy crossovers, woofers, and tweeters is far more exagerated than most would believe compared to a well executed single driver speaker because they've never heard one. Is it rational to justify one approach or condemn another without evidence?

I'm not condemning anything except that it has always been one philosopy vs another for many reason.  What I'm saying is that the very reasons you like single driver systems is why you would like DEQX.  I'm not defensive, just quite convinced of the possibilities [/quote]

[mac]

To say that it overrides all other tradeoffs and all other decisions in the signal path....well, I, for one, know it didn't in my case...

In your case Ted, you were using about 20% of its capabilities.

[JohnnyLightOn]

So you're using this as your source as well?  Or can you use an outboard DAC with it if you prefer the sound of your DAC?

Also, if you have a pair of three-driver speakers, do you use six separate amps??  How does that part work?

Thanks for the additional info!  

[ted_b]

Ted_B

Holly crap, your room is killer

yes, wery nice indeed.  but one thing you can do, imo, for a big improvement - this topic yust came up in another thread re: florian's new rm30's - make the coffee table go away!  

doug s.

Hell, I'm the one that brought up the damn coffee table to Florian in that post in the first place (my post is right under his first pix)!!!!  

I have a thick blanket on it, and underneath that blanket is some foam.   It's fine, really.  It's marble table that ain't gonna move for listening, then back again for HT chips-beer-what not.  With the foam and blanket, and the side sonex first reflection points it's pretty good, I gotta tell ya.

And yes, Mac, I AGREE that I was using only 20% of it, and stated it in other posts more than a few times (I don't want to bash the DEQX; Kim, Ian and my wonderful dealer...he knows who he is....were very supportive.. )That's why I said the million lines of code for the FIR and room correction are State of the Art, no question.  A bargain at $3k.  I just didn;t like the DACS and am stuck with analog.

Ted

[John Ashman]

Ted certainly has earned the right to comment, but as I told him, the RM40s wouldn't be my pick for the most DEQX-able speaker as it would be hard to measure and correct.  Not impossible, but it's not a good measure of the what it can do.  I don't generally recommend ribbons or line arrays as the ideal if you actually want to do driver correction.  It is best to do crossover, room correction and then use the parametric EQ for any problem spots.  As I recall, Ted didn't try tri-amping, something that is critical, which leaves it only useful in his system as bass correction, and, as Mac said, that's about 20% of the capacity.  So, it's not fair to judge the system as limited without fully engaging it's capacities.

I do disagree with Ted's feeling about the transparency.  I think this is more perception than reality, IMO.  If you think an AD/DA conversion will hurt your sound, then, in your mind, it will.  Others are surprised by its competency, if not excellence in this regard and the digital parts quality is quite good.  If you do it right, you'll gain so much more than you lose that there's simply no comparison.  If you think an ADC/DAC is lossy, think about pushing the signal through a bunch of capacitors, resistors and inductors!  There's no contest as to which process is more transparent.  

As for using an outboard DAC, that would make no sense as you would be simply adding a completely unnecessary DAC/ADC step.  While it may not hurt in any obvious way, it wouldn't help in any way.

[Marbles]

Ted, must be a bitch to watch movies with that hemholtz resonator in the way


Beautiful room man....

John, Ted has the TOTL VMPS Elixirs, not the RM40's.

[ted_b]

Ted, must be a bitch to watch movies with that hemholtz resonator in the way


Beautiful room man....

When I watch movies I just put it on the coffee table.....

Ted