The 12 Most Significant Loudspeakers of All Time

FrantzM

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Apr 20, 2010
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#61
Is the DQ-10 Time coherent? And most studies point toward phase coherence as unimportant.. Most speakers are not phase coherent by that I mean MOST... No current uber speaker you want to think of is not phase coherent ..There could be some exceptions. I would actually go as far to say that there aren't two (or any?) on the TAS list.
 
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DonH50

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Jun 23, 2010
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#62
That was one of the stated design goals. TAS or Audio (forget which) had an interesting article comparing the step and/or pulse response of various speakers showing if they had achieved time coherence. I am not sure I still have the article; I am quite sure I cannot find it. I know my Maggies did well, as did an electrostat (do not recall which they tested), and the DQ-10 did not do badly. IIRC some of the popular leaders did not do so well, perhaps indicating other factors are at play (understatement). I think the B&W 801 was best of the "conventional" designs, though the number of speakers in the test was small (under a dozen, I am almost certain).

We repeated several of the tests in the store I worked and with various systems around town. I used an impulse test, mic'd about 3' away, and looked for just the initial response as room stuff wiped out anything else. A shame, that last, as it was pretty obvious some of the speakers had fairly long tails and I would have liked to have seen more time. I repeated some in a field but it was hard to pull the info out of the noise, and for some strange reason folk were a little leery of setting up say their Acoustats or Apogees out in a field to measure... :)

BTW, we used a ML or Krell monoblock (don't remember which) for the tests to limit variables; I made measurements with some other amps by request but am not sure I remember the results. The only ones that stick out is that Maggies were least amp-sensitive, and a relatively low-powered tube amp on a pair of 801's resulted in a very ugly result even though the owner loved the sound (the rest of us did not, except in the upper mid and above, FWIW). There were some strange double-pulse response in the panels, especially the 'stats (much less so in the Maggies). Eventually I think we attributed that to mechanical waves rippling across the panels after the initial impulse; the Magnepan panels were heavier and more damped compared to the electrostats so did not seem quite as affected by this.
 

MylesBAstor

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Apr 20, 2010
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#63
Is the DQ-10 Time coherent? And most studies point toward phase coherence as unimportant.. Most speakers are not phase coherent by that I mean MOST... Any of the current uber speaker you want to think of are not phase coherent ..There could be some exceptions. I would actually go as far to say that there aren't two (or any?) on the TAS list.
Could u please point us to those studies Frantz?

As far as PC designs, Thiel, Vandersteen, Spica and Joseph Audio come immediately to mind. I also think Revel discusses it in their literature too as well as Linkwitz.

http://www.vandersteen.com/model7wp.pdf

http://www.stereophile.com/content/vandersteen-2ce-signature-loudspeaker-measurements-part-2
 

FrantzM

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Apr 20, 2010
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#64
MYles

Oh! There are and several ... It bears to repeat that The overwhelming majority of Audiophiles (and professional) loudspeakers on the market are not phase coherent. That would suggest that most audiophiles and designers do not see Phase Coherence as the most important attribute of a speaker. I am not sure I have seen many studies on the necessity of Phase Coherence in a loudspeaker , besides the marketing material of the few speakers manufacturers of Phase Coherent speakers.

Som material on Phase Coherence not being important in speaker design ...
HERE... A few snipets on the audibility of Phase Coherence inSpeakers:
AES Paper on Phase Coherence

This Post here on the WBF is interesting ...
This Article by Ethan Winer

Article from Stereophile

Also these papers by:
Floyd E. Toole, "Loudspeaker Measurements and their Relationship to Listener Preferences: Part 1," J. Aud. Eng. Soc. Vol.34 ( April 1986).

F.E. Toole, "Loudspeaker Measurements and their Relationship to Listener Preferences: Part 2," J. Aud. Eng. Soc. Vol.34, (May 1986).

D.D. Rife, "Introduction, Theory, & Loudspeaker Time Coherence," DRA Labs MLSSA Reference Manual v.10.0A (1996).
=======================================================================
There a lot more
 

MylesBAstor

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Apr 20, 2010
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#65
MYles

Oh! There are and several ... It bears to repeat that The overwhelming majority of Audiophiles (and professional) loudspeakers on the market are not phase coherent. That would suggest that most audiophiles and designers do not see Phase Coherence as the most important attribute of a speaker. I am not sure I have seen many studies on the necessity of Phase Coherence in a loudspeaker , besides the marketing material of the few speakers manufacturers of Phase Coherent speakers.

Som material on Phase Coherence not being important in speaker design ...
HERE... A few snipets on the audibility of Phase Coherence inSpeakers:
AES Paper on Phase Coherence

This Post here on the WBF is interesting ...
This Article by Ethan Winer

Article from Stereophile

Also these papers by:
Floyd E. Toole, "Loudspeaker Measurements and their Relationship to Listener Preferences: Part 1," J. Aud. Eng. Soc. Vol.34 ( April 1986).

F.E. Toole, "Loudspeaker Measurements and their Relationship to Listener Preferences: Part 2," J. Aud. Eng. Soc. Vol.34, (May 1986).

D.D. Rife, "Introduction, Theory, & Loudspeaker Time Coherence," DRA Labs MLSSA Reference Manual v.10.0A (1996).
=======================================================================-
There a lot more
Ok can't access the first but how about some unbiased observations?

There are certainly some interesting pts in the SP piece--though the problem is that there are so many variables, isolating one is near impossible. One other point Ois about phase errors --though think the pts about on axis response and diffraction (after all the DQ10's drivers were also mounted to minimize diffraction) are important. I'd like some like Richard Vandersteen though to share his thoughts on the relative importance though. The man is no slouch when it comes to engineering
 

DS-21

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Aug 23, 2010
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#66
As far as PC designs, Thiel, Vandersteen, Spica and Joseph Audio come immediately to mind. I also think Revel discusses it in their literature too as well as Linkwitz.
I'll give you most Thiels, Vandies, and the triangular Spica (is that the only one? It's the only one I've ever seen) as having phase coherence at some measuring angles. To my knowledge, only the ESL-63 and Danley's Synergy horns are time coherent all over the place.

Joseph Audio, at least when I last heard his speakers, used elliptical-slope crossovers that were the opposite of time-coherent.

Furthermore, "discuss[ing] it in their literature" is of course no guarantee of anything having to do with a technical claim. Often, in audio, it is in fact the exact opposite...
 

MylesBAstor

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Apr 20, 2010
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#67
I'll give you most Thiels, Vandies, and the triangular Spica (is that the only one? It's the only one I've ever seen) as having phase coherence at some measuring angles. To my knowledge, only the ESL-63 and Danley's Synergy horns are time coherent all over the place.

Joseph Audio, at least when I last heard his speakers, used elliptical-slope crossovers that were the opposite of time-coherent.

Furthermore, "discuss[ing] it in their literature" is of course no guarantee of anything having to do with a technical claim. Often, in audio, it is in fact the exact opposite...
Absolutely, but most studies done in audio are pseudo-science. Most are simply correlations rather than cause-effect. And as my stat professor used to say, just because you were born in a garage doesn't make you a car.

People who do original research like Keith Johnson don't need to go around and toot their horns. Here's a guy who's probably forgotten more than most people know.

In the end, I don't get hung up with technical explanations and worry about whether it sounds like music to me :)
 

FrantzM

Member Sponsor & WBF Founding Member
Apr 20, 2010
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#68
Myles

Which link you can't open? What "unbiased" obsevations would like to see?
Now would you at least concede that most speakers on the market are not remotely phase coherent even some that claim to be? Also does Joseph Audio claim that their speakers are Phase Coherent? The crossover used in their products can't be phase coherent ...
About the SP articles, there are not that many variables.. Just one .. A speaker is phase coherent at all frequencies it covers or it's not ...
 

MylesBAstor

Well-Known Member
Apr 20, 2010
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#69
Myles

Which link you can't open?
The first one

What "unbiased" obsevations would like to see?
C'mon Frantz. JJ, Ethan and their gang of four are hardly unbiased. On top of that, they're all basically armchair quarterbacks. It's real easy to be critics when you've never designed and released a commerically viable consumer high-end audio product.

Now would you at least concede that most speakers on the market are not remotely phase coherent even some that claim to be? Also does Joseph Audio claim that their speakers are Phase Coherent? The crossover used in their products can't be phase coherent ...
About the SP articles, there are not that many variables.. Just one .. A speaker is phase coherent at all frequencies it covers or it's not ...
To be honest, I never looked to see who claims to be phase coherent. And as far as variables, what I was referring to which variables are the most important when it comes to the sound of a speaker. No variable works in isolation. So you've got basic design, drivers and construction, diffaction, xover type and construction, cabinet construction, parts and materials, etc. etc.
 

FrantzM

Member Sponsor & WBF Founding Member
Apr 20, 2010
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#70
Myles

The thread is not about Phase coherence. Your last post however needs to be answered to. I provided numerous links only one of these was from Ethan Winer. Regardless, can you disprove his conclusions? The view of the vast majority of speaker designers do not infirm his conclusions. Can you?
Now I repeat there is ONE variable and it is measurable: Phase Coherence. All the other "variables" you mention should "cohere" toward this measurable parameter: Phase Coherence. A speaker is phase coherent or not. First order corssover is a necessary but not sufficient requirement for Phase Coherence. At least in a an analog crossover, I don't know what can be done in digital.
 

JackD201

WBF Founding Member
Apr 21, 2010
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#71
I'm reading this thread with some amusement. I don't get how some people can be so assertive and totally convinced that they are right yet can't answer simple direct questions. When that happens I don't think I can be blamed for finding these people lacking in substance no matter how convincing their rhetoric might be. I have a million times more respect for the person that says "I don't know", a billion times more respect for a person that says "I'll find out" but really, a ducker, bob and weaver? Waste of time.

BTW Frantz this may follow your post but I do not consider you in this category at all. We may not agree all the time but you always engage.
 
#72
Just a phase?
As DS-21 mentioned our speakers specifically, I figure it is something I can comment on at least from a designer’s point of view.

If one simulates an arbitrary phase shift with a DSP “all pass” filter or other method and then listens with headphones or speakers, one will conclude that only on some program material is there any real audible difference and at that, it can be hard to say which way is better “with or without” the extra phase rotation. Beyond the purists goal of “wire with gain” or in this case electrical signal in equals acoustic signal out, there are reasons this area matters and why it is so hard to address that it usually isn’t.

Richard Heyser was the first person I know of to write about and also find a way to measure a loudspeakers time delay and then acoustic phase. The acoustic phase is the alignment of the acoustic pressure relative to the input signals phase when all the fixed time delay is removed (at a theoretical zero distance).

In other words, producing a sine wave, the actual pressure at the drivers radiator may be behind at or ahead of the electrical signal, depending on the driver’s acoustic phase. “Minimum phase”, most drivers are that at least down low in frequency, what minimum phase means is that there is a corresponding phase shift for ANY change in amplitude and all the phase wrap caused by time delay has been removed from the display.
While most popular measurement systems use a pseudo random signal to calculate the impulse response and then magnitude and phase, one can measure magnitude and phase and calculate impulse response. Any systems impulse response is set by the systems magnitude and phase response, they are two views of exactly the same thing.

When you add two identical signals together through a pair of resistors, one has simple vector addition and if one of the two were to be reversed, the result is they still add coherently, +1 added to -1 equals 0, cancellation. With the phase at say 120 degrees difference instead of 180, now one plus one equals one and as the differences approaches zero, the result gets closer to 2.

In other words, with coherent addition, the result is the vector sum of the two signals.
With two loudspeaker drivers, this is also how it us at least for subwoofers. With acoustic sources, one has coherent addition up to the point where the two sources are more than about 1 / 4 wavelength apart. With larger spacing, the two sources radiate independently and produce an interference pattern comprised of a series of lobes and nulls. With an interference pattern, if one reversed one of the two sources, the result isn’t cancellation to zero but rather the pattern of lobes and nulls change.
In home hifi, people mostly believe what the magazines tell them and most hifi speakers appear to be partly designed based on expectations as opposed to acoustics or physics as it applies to the subject.
But in commercial sound, the room problems are much worse and all the acoustic problems with loudspeakers get worse, the greater the acoustic power one tries to produce.

The flaws always get louder faster than the desired signal with increasing input level.
For our company, this is where I chose to focus because as an old friend and former hifi reviewer said to me once “there are speakers that go loud and there are speakers that sound good but none do both”.
The real problem here is that the larger the acoustic power you need, the large number of drivers and frequency divisions it takes. That is needed because each time one doubles the distance to the source, the SPL drops by 6dB (1/4th).

You may have noticed that all things equal, there is an inverse correlation between the size of a sound system and the fidelity. You may have noticed that a pair of little fostex FR drivers on a large flat baffle can produce a phenomenal stereo image or that KEF is now making a speaker intended to radiate as a single point source. You may have noticed that in an outdoor venue, if the wind blows, that the sound of a large line array changes wildly or is swishy.

These effects are caused by the interference patterns the speakers radiate (of not.).
For our speakers, the Synergy horn design allows all of the drivers to add coherently into a single acoustic source. This is very important in commercial sound as the object is to make the sound “the same” everywhere in front of the speaker. With the crossover design, the physical position of the drivers and the acoustic coupling between them allowed a crossover that eliminates the “all pass” phase of normal crossovers and the result is some of the speakers can produce a square wave, over a wide band, with little position dependence out front. Signal waveshape in equals acoustic pressure waveshape out. While not thought to be important, is the result of having all the drivers act like a single wide band source.

For the small Fostex drivers, while limited in bandwidth and loudness, they radiate as a single source up to a fairly high frequency. This means that standing in front of just one driver, what reaches each ear is very nearly the same and as a result with one’s eyes closed, it is harder to locate the speakers physical depth using ones ears, the direction sure but not how far away. Most multi-way speakers produce an interference pattern due to the driver spacing etc and so are easy to localize in this kind of test. To localize depth or position in depth with eyes closed, one needs clues, differences between right and left ears. Switch to stereo and the fostex driver produce a strong image anywhere between L and R speakers. An indicator of how much self interference any speaker has is audible when you do the one source, eyes closed test with a human voice. With a “perfect point source speaker” you should not be able to easily hear it’s depth location just the direction, just a voice floating in front of you some distance away.

While the Synergy horns do this too, our business is focused on larger scale sound where this solution makes the audible difference large enough for venue owners to choose an unknown company based on sound quality. Myles, I see your in NY, if you have been to the Madison Square park concerts this season, they have used this kind of speaker instead of the normal line arrays.
To a degree one can “hear” the effect of radiating as a coherent single source in this video (put on headphones), notice how the sound doesn’t change appreciably as he moves around and out to a distance later measured to be 700 feet.
http://www.youtube.com/watch?v=pk54IFD4znw

For a true point source, the spectral balance doesn’t change with distance, only the loudness falls and hf air absorption.. More noticeable is that the wind has hardly any effect as the wind moves the beam around because of the homogeneity of the radiation.
The first public demo of the JH-90 speaker at the Infocom trade show two years ago lead to the BYU stadium installation and Northwestern University, the sound quality of those two jobs brought in 12 other stadium sales, the most recently completed is Lambau field in Greenbay Wi where a large conventional sound system was just pulled out.
The cool part (for me), I get to design and refine most of these in my living room as part of my home hifi, I used to dream about coherence combined with not running out of headroom back when I made electrostatic speakers.
So, phase response in a real speaker (as opposed to simulations of only phase shift) is usually tied to the physical orientation / spacing of the drivers and also tied to the presence of or absence of an interference pattern which can be plainly audible as it is localizable, the speaker is yelling out “here I am” when ideally it’s location in depth should be ambiguous as it is not part of the recorded image .

In the development of the Unity and then Synergy horns (over the last 12 years) I noticed this effect and was puzzled by it. AS they got closer and closer to a single broadband source, it got harder to hear how far away they were with your eyes closed, subjectively the sound got simpler and simpler for lack of a better descriptor..
Best,
Tom Danley
http://www.danleysoundlabs.com/
 

LL21

Well-Known Member
Dec 26, 2010
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#74
Tom,

i wont pretend to have understood your entire discussion there, but i did appreciate your taking the time to write it down. coming back to simple man's terms, let me ask you this. Since you get to listen to your jh'90's in your house...what would you say about using those speakers (normally for 1000' distances) in a large 36' x 20' living room? Crazy? Stupid?...or compared to Alexandrias and Arrakis' etc, actually they would not only be applicable (and competitive) but in fact the quality would be great because they would barely be breaking a sweat to compete given that they are typically obligated to create smooth sound for stadiums?
 
#75
Hi Loydlee

Well, the JH-90 might sound fine but really would be the definition of overkill as a stereo pair in a living room.
Consider that the Omnimax to Imax theater conversions use something much smaller, the SH-96 as in this one;

http://www.danleysoundlabs.com/danleyport.asp?ID=58

Or a new cabinet the SH126 (not on the web site yet).

I use a much smaller cabinet yet at home normally, the SH-50’s Right and left and these are more than enough for a living room.
They are used in larger spaces than living rooms but I like the headroom.
The sensitivity is about 100dB 1w 1m and this box (as I tried it) can reproduce a square wave from about 260Hz to about 1900Hz, anywhere from fair to excellent looking on an oscilloscope.

Enough people have heard these by now that you could do a Google search and find other peoples impressions as I am unavoidably biased haha..

While none of the Synergy horns has a “minimum listening distance”, what one does hear quickly is the large reduction in side wall reflections because of the directivity. The cabinets with an angle cut on the sides can be arrayed with another speaker without audible interference or seam but they can also be placed on a wall or floor (on that angle) and not produce a reflection.
In a narrow room, this allows the image to be much wider as the speakers can be on the wall boundary.

The down side is that because nearly all of our sales are for commercial spaces, we do not normally have “wood finish” cabinets in stock.
Also, while my personal interest is and always has been “hifi” the company has a growing niche in commercial sound.
I have started on a smaller “hifi” speaker a number of times but have always been dragged off (mentally) on other products.

An interest of mine obviously i guess is the stereo image and I have been working on a microphone array to capture it. If interested, try a couple of the wave files at the bottom of the page below. Use headphones as this is the “front” 120 degree stereo image (if it were your eyes looking forward). I am working on a 5 channel version at the moment.
Sound files at bottom of this page;

http://www.danleysoundlabs.com/technical downloads.html

Best,
Tom Danley
 

LL21

Well-Known Member
Dec 26, 2010
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#76
Thanks, Tom. Sounds interesting! i will do some further digging on your website.
 

slbender

New Member
May 7, 2012
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#77
Original intent of: The 12 Most Significant Loudspeakers of All Time?

Getting back to what I suppose was the original intent of this list of twelve, I think the Hill Plasma is probably OK for such a list - even if no more than five people ever owned it. Still, considering there were neither time nor geographic limitations imposed (that I know of) I would have thought three excellent speakers that didn't make the list, probably should have, include:

1) The Leak "Sandwich" speaker circa 1959, prior to transistors and high power amplifiers, this Brit two way speaker was both highly efficient, and was highly regarded in the late fifties, even termed "The world's best sounding loudspeaker" or some such exuberant phrase, in reviews way back when. If I could have repaired the rubbing voice coils on my pair, I'd probably be using them today with my low powered modern day SET AMP (circa 2007) - an all 5687 design. :eek:

2) The KLH 6, an attempt at a low priced competitor to the AR 2ax/5/3a in a two way design, it and also the KLH 17 (the 10 inch version) sold oodles and oodles, making KLH a household name. I guess it set the low-end price point for home speakers for at least half a decade or more, bringing HiFi and Stereo to a wider audience during the "Golden Age of Vacuum Tubes". They truly the preceded the rather similar, and I would say highly derivative "Large Advent's" which came later. Perhaps the true claim to fame of the KLH 6 and 17, their original cloth suspensions still outlasts the test of time, unlike the Large Advents, the Carver Amazings, the DQ-10's, and so many others. :)

3) The Dynaco A-25, with a true bookshelf size, this Danish import reportedly sold over a million, whether that was singles or pairs, I don't know. It was a very popular speaker and while its treble was a mite rolled off, consistent with it European heritage, its minimalist first order simple crossover allowed it to produce prodigious bass from the "aperiodic" tuned design and louder undistorted SPL's than just about anything else in its size, or in sight. At its original list price of $79. it was both a bargain and at least a million others felt likewise, back in the day. Its rubber surrounds were also timeless, and it was notably one of the first speakers to accurately reproduce a square wave (for those who like square waves). :cool:

Back then I switched to other brands and types, but sooner or later I always came back to the A-25's until I built my own 4 way speakers some 30+ or so years ago - which I still use today. I have been meaning to upgrade the crossovers for over a decade now, when will I find the time? ;)


-Steven L. Bender


I've heard a plasma tweeter in a horn system, running above a 2" horn loaded compression driver. Some of the best top end I've heard.

It's hard to come up with a list like this. I had a crack at it on my blog, although I based my list to a greater extent on innovation and merit. So an under-rated speaker might make my list and popularity or having a following were rated lower.

Here's mine:
http://redspade-audio.blogspot.com/2010/11/10-most-significant-speakers.html
 

Mosin

[Industry Expert]
Mar 11, 2012
891
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#80
I find it interesting that none of the models of the old pro speaker companies were mentioned. Western Electric certainly deserves a nod, as does Klangfilm, Tannoy and RCA. Both Tannoy and RCA had specific models that definitely added to today's audio experience. For example, the RCA LC-1A was probably the first speaker that was designed with combined consideration for time coherence, effects of cone stiffness, tweeter dispersion and room size. Consumer companies like to take credit for all those things, but it just ain't so. They were merely following leaders from the distant past.

I suppose the results of the reviewers at TAS are due more to geographic location than anything else. Appreciation of those old speakers in the Far East is a given, and it is increasing dramatically in Europe. In fact, the room which garnered the most visits at the last Munich show was one that featured a Western Electric speaker, and their press drooled over it.
 

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