Howard Ferstler, Zilch, and the AR-3a.

[Zilch]

"The facts are in AND YOU'RE WRONG!"

Liking them is NOT wrong. I never said that, nor any of the rest.

It's the REASONS that are wrong, and getting them RIGHT is essential to maintaining their enjoyability and value.

How many others have given up in the face of pervasive ignorance?

We know more now than ever before, and can provide better informed assessments of issues and answers; the irony is that the data has been available for 40 years....

[Shacky]

I'm pretty sure nobody ever actually said "WHARRGARBL" either.

Wasn't that Howard Dean

[Guest winters860]

It's the REASONS that are wrong, and getting them RIGHT is essential to maintaining their enjoyability and value.

I find this disingenuous coming from someone who doesn't enjoy the AR-3a and thinks it's overvalued.

How many others have given up in the face of pervasive ignorance?

I give up. I'll leave it up the peanut gallery to decide as to why.

[Zilch]

If your measurements are the same as those from 40 years ago - what has been added to the AR 3a scientific discussion?

Once again distinguishing yourself as a master logician, obviously, Shacky!

I find this disingenuous coming from someone who doesn't enjoy the AR-3a and thinks it's overvalued.

Indeterminate at this point, actually, but if so, count on me hyping them for all they might be worth.

The West Coast sound for listeners of classical music was unbearable. Its harsh shrill high frequencies all but unlistenable in a home. In a studio as a monitor it took a 31 band Altec Acousta-voice equalizer costing almost twice what an A7 or A7-500 did to flatten its frequency response.

Mids. They didn't have any highs. I can flatten them for $20 with a tank filter. Giving them highs takes a bit more, but not much.

How fortunate low cost graphic equalizers appeared on the scene shortly afterwards to solve that problem. Too bad most audiophiles don't know how to use them properly.

YEAH, baby, SMACK those AR3a tweeters with the requisite 10 dB of boost to flatten their in-room response.

WAIT! Where'd it GO....?

[Zilch]

The AR speakers (like KLH to follow) were designed with the best science available at the time, however, that design and its outcome was validated with the ear.

KLH Model 6 was designed by ear. It also measured superbly within its frequency range.

UT, oh, we have an apparent disagreement.

Who has the definitive statement of KLH design philosophy?

Does "Octave by octave balance" mean something more than pink noise?

Or was that Advent?

[i'm SO confused.... ]

[soundminded]

Once again distinguishing yourself as a master logician, obviously, Shacky!

Indeterminate at this point, actually, but if so, count on me hyping them for all they might be worth.

Mids. They didn't have any highs. I can flatten them for $20 with a tank filter. Giving them highs takes a bit more, but not much.

YEAH, baby, SMACK those AR3a tweeters with the requisite 10 dB of boost to flatten their in-room response.

WAIT! Where'd it GO....?

"QUOTE (soundminded @ Apr 25 2009, 08:03 PM)

How fortunate low cost graphic equalizers appeared on the scene shortly afterwards to solve that problem. Too bad most audiophiles don't know how to use them properly.

Zilch;

YEAH, baby, SMACK those AR3a tweeters with the requisite 10 dB of boost to flatten their in-room response."

I see nothing wrong with that. The difference between electrical engineers and clueless audiophiles is that audiophiles have no real knowledge of how anything actually works in the real world, only what advertisers and rag hobbyist magazines who make their profits in part from advertising tell them.

For example. RIAA and NAB have equalization curves that span 40 decibels, one thousand times the 10 db boost you suggest for AR3a tweeters. Between the recording and playback of the master tape, the mixdown, and the cutting and playback of vinyl phonograph records, even without the creative knob twiddling of the mastering engineer, there are at least six equalization circuits between the microphone and the phono preamp output stage. If you add Dolby A professional noise reduction, you can add another 8 and those have filtering characteristics which are dynamically controlled by the instaneous amplitude of the signal itself in each of four frequency bands. Any error in calibration is a disaster but it's the only way around substantial tape hiss for wide dynamic range material recorded on analog magnetic tape used in the manufacture of phonograph records. While we're at it, let's not forget peak limiting and dynamic compression. Any further signal processing such as artificial reverb is purely discretionary and mostly beyond the control of the end user. BTW, FM radio and analog color television would also have been impossible without considerable equalization expertly used.

[Shacky]

UT, oh, we have an apparent disagreement.

Who has the definitive statement of KLH design philosophy?

Does "Octave by octave balance" mean something more than pink noise?

Or was that Advent?

[i'm SO confused.... ]

Why are you so negative Zilch? Henry Kloss's commented on his Model 6 possibly being the best of his designs in terms of Octave over Octave balance or performance. And you try to turn that into a pithy quib?

You have an obvious disdain for classic NE speakers (now AR, KLH, and Advent). It's either that or you are trying to impress folks you know have more knowledge than you by taking a negative slant. Either way you'd be more appropriate taking it to a Lansing or econo-wave site.

[Zilch]

Why are you so negative Zilch? Henry Kloss's commented on his Model 6 possibly being the best of his designs in terms of Octave over Octave balance or performance. And you try to turn that into a pithy quib?

The drill is the same, a quest for knowledge. You and others parrot these descriptions as if they mean something. What do they MEAN, Shacky? Where are the definitive white papers outlining KLH and Advent design philosophies equivalent to Allison & Berkovitz's presentation of AR?

This site's focus is "East Coast" loudspeaker design; what's that ABOUT? How did the various manufacturers incorporate features identifiable as such? How did the fundamentals evolve over time? How is that reflected in objective measurements of their performance today? These are matters of import to many, and Mark has suggested above that he will provide a specific forum for their exposition and discussion.

You have an obvious disdain for classic NE speakers (now AR, KLH, and Advent). It's either that or you are trying to impress folks you know have more knowledge than you by taking a negative slant. Either way you'd be more appropriate taking it to a Lansing or econo-wave site.

You characterize my view of this as somehow inherently negative; that's you "spinning" it, and I suspect the reason is that you don't want to accept the challenge of understanding East Coast loudspeakers. Who other than myself has measured ARs, Advents, KLHs, and Dynacos (thus far) and presented the data for all to evaluate in an attempt to get at the fundamentals? Acknowledge that it was only by virtue of me holding Howard's feet to the fire that the basics of AR3a are now generally available here.

Did others know this stuff? Well, sure, but they apparently considered it too arcane or too controversial for prime time. Did they themselves understand it? That's not so clear in the light of further scrutiny: Howard's all poised to administer Toole a public thrashing for not giving his favorite ARs and Allisons the attention he believes they deserve. We know where Howard's head is at, and it's the same place Stereophile called out in their review of his book on Hi-fi. I have shown that Toole and Allison are in substantial agreement on the matters of most significance; if anything, it's Howard's perspective that I have turned on its head here....

[soundminded]

The drill is the same, a quest for knowledge. You and others parrot these descriptions as if they mean something. What do they MEAN, Shacky? Where are the definitive white papers outlining KLH and Advent design philosophies equivalent to Allison & Berkovitz's presentation of AR?

This site's focus is "East Coast" loudspeaker design; what's that ABOUT? How did the various manufacturers incorporate features identifiable as such? How did the fundamentals evolve over time? How is that reflected in objective measurements of their performance today? These are matters of import to many, and Mark has suggested above that he will provide a specific forum for their exposition and discussion.

You characterize my view of this as somehow inherently negative; that's you "spinning" it, and I suspect the reason is that you don't want to accept the challenge of understanding East Coast loudspeakers. Who other than myself has measured ARs, Advents, KLHs, and Dynacos (thus far) and presented the data for all to evaluate in an attempt to get at the fundamentals? Acknowledge that it was only by virtue of me holding Howard's feet to the fire that the basics of AR3a are now generally available here.

Did others know this stuff? Well, sure, but they apparently considered it too arcane or too controversial for prime time. Did they themselves understand it? That's not so clear in the light of further scrutiny: Howard's all poised to administer Toole a public thrashing for not giving his favorite ARs and Allisons the attention he believes they deserve. We know where Howard's head is at, and it's the same place Stereophile called out in their review of his book on Hi-fi. I have shown that Toole and Allison are in substantial agreement on the matters of most significance; if anything, it's Howard's perspective that I have turned on its head here....

"Where are the definitive white papers outlining KLH and Advent design philosophies equivalent to Allison & Berkovitz's presentation of AR?"

I don't think there are any. I think Kloss gave a speaker and an equalizer to ??? and told him to bring it back in a week the way he thought it sounded best. That became the target for his design sound. Evidently a lot of people liked it too because it was very popular and stayed in production for about 13 years. I also like it, I thought it had a clear relatively accurate sound compared to other speakers. One criticism of it I think by Consumers Report was that it had some sort of peak in the upper midrange, exactly the spot where you said room acoustics absorbed much sound. I had a chance with some other people in my college days to compare the similar KLH Model 17 with AR3 for an extended period. The AR3 had obviously superior bass but the KLH Model 17 sounded more like real music to us, that was the consensus. I don't remember what cartridge we used, probablly an Empire or Shure, the turntable was Empire 398 and the amplifier was a 60wpc (IHF measurement, about 50 wpc RMS) HH Scott Mosfet receiver. This was in the late 1960s. Because the receiver had blown up once and the servicing technician blamed it on the low impedence of the AR3, it was operated with 2 ohm resistors in series with each one. CBS Technology Center tested the Model 6 and wrote a full report about it for High Fidelity Magazine. The speaker had fairly flat on axis response from 40 hz to 16 khz, HF dispersion was good as indicated in a polar plot they presented, but the most outstanding feature of the measurements was transient response which was illustrated with typical tone burst oscillophotographs. The looked just about perfect. 44 years later I still have mine and I acquired another pair. I haven't listened to them in years. Perhaps I'll hook them up. I've got a brand new 100 wpc Sherwood Receiver that's been sitting around since last fall and several brand new dvd players that I bought last Labor Day, none of which have been out of the box. Time to let them see some dust.

[Zilch]

One criticism of it I think by Consumers Report was that it had some sort of peak in the upper midrange, exactly the spot where you said room acoustics absorbed much sound.

CBS Technology Center tested the Model 6 and wrote a full report about it for High Fidelity Magazine.

There are apparently also reviews of ARs not posted in the CSP library. Members must have these for many of the designs featured here, and I suggest that they put some effort into getting the originals or quality scans of them in to Mark for potential posting. There's lots of good information here, but it shouldn't be a one-way street, in my view....

[kkantor]

There are apparently also reviews of ARs not posted in the CSP library. Members must have these for many of the designs featured here, and I suggest that they put some effort into getting the originals or quality scans of them in to Mark for potential posting. There's lots of good information here, but it shouldn't be a one-way street, in my view....

1- Mark and I have discussed this for years. There are unresolved IP issues that discourage the posting of magazine articles and reviews.

2- An attempt to render a comprehensive critical history of loudspeaker science particularly in terms of a dialectic between an analysis of Toole and an analysis of Allison gets onto some thin ice. Any study of history must turn up or down the gain on both similarities or differences, as the historian chooses to understand them. I'm talking all critical theory here, not just audio. Good historians, of course, take a position, but also acknowledge the validity of alternative lenses.

3- There are at least three very smart, open-minded and experienced loudspeaker design pros who post here.... probably 100 years of study and output between us. If we can keep learning, and we can, so can everyone. It's all about dialog, not debate.

4- In 1975, when I was studying with Dr. Bose, I "suggested" to him that he power the direct and reflected transducers in the 901 via separate amps, so that they could be eq'd and delayed independently, allowing some independent control of first arrival and "room response." He replied that this had been considered, and experimented with, but that it was not held to be a sufficient market advantage to justify the price. I bring this up to make two points: that these concepts are not new; and, subjective commercial appeal is a powerful partner of science.

5- There are several exclusion principles at work when any audio transducer operates in a listening room. No matter what approach is taken, no matter how skillful the engineering optimization is, the Gordian Knot is not cut. There is, if you will, a conservation of distortion. After a point, one can only better one aspect of performance at the expense of another.

-k

[Shacky]

Howard,

I love my KLH6's too. In fact I just hooked them up today while enjoying Peter's Eico HF-81 reworked my Sam Kim. Jennifer Warnes the Hunter on right now.

When I got intersted in Vintage a few years ago I read the AR or KLH acoustic suspension speakers need lots of power - more readily available with Solid State. So I have Sanui 890DB and 9090DB rceivers.

Then I picked up a nicely restored/converted Fisher 681-A console tube amp running 7591's at ~ 30WPC. I had heard the KLH 6 were "voiced" for tubes - and boy do they sound wonderful!!! So do my AR 2AX and AR 5's (now given to my son for posterity). The 3a's seem underpowered with this tube amp.

With Peters Eico - I have seen/heard the promised land! Phono section is much better than anything I have owned. My KLH 6's sound wonderful. So do my AR 5's - had my son bring them over for a listening session.

As far as I'm concerned, Let Zilch bash them all he wants. There'll be more around for those of us who appreciate them.

[Zilch]

Trust me, Allison and Toole do NOT agree about some very important things when it comes to speaker design and speaker/room interactions. They obviously will agree in some respects, but where they do not agree is important.

You have apparently not yet made the connection. When Allison says:

3. In the range of 250 to 2500 Hz, a decade of primary aural sensitivity, the response is within +/- 1 dB. Keep in mind that this curve shows what the loudspeakers are delivering to the listeners' ears. If loudspeakers are still the "weakest link," it isn't evident here. [Emphasis original]

he neglects to remind readers that the flat power response measured in AR's "special" highly reverberant chamber has been boosted for the in-room measurements; both controls are set to "Max." How much boost above flat energy output was required for AR3a's to play flat in-room in this region? See Fig. 8: it looks like 3.5 dB to me at 700 Hz, and 7.5 dB at 2500 Hz, and the tweeter is also boosted 3 dB in the last octave. See also Figs. 17a vs. 17b where it's clear that reverberant flat power response occurs with the controls set to "Normal," instead.

This indicates that the absorptive influence of the room extends to far lower frequencies than you have thus far conceded, and that the direct field progressively dominates over any imaginary reverberant one above a relatively low transition frequency, certainly lower than the upper midrange region you presume. It's not terribly difficult to see that the in-room response curves reflect the integrated anechoic response over the listening window shown in Figs. 6 - 16 more accurately than the reverberant chamber power response, and thus, your interpretation of the presented data as substantiation of a "total energy, max dispersion" thesis fails.

Further, note that the individual in-room measurements were done with 1/3 octave resolution and additionaly "smoothed" by averaging 22 of them together in compiling the summary in-room curve. It's not at all surprising that response anomalies would not appear. Toole devotes virtually the entirety of his Chapter 9 to the inaudibility of combing without reliance upon an imaginary reverberant field. However, it's easily seen in Figs. 6 - 16 that much of the wide-dispersion driver energy above 2.5 kHz never makes it past the AR3a cabinet and into the room in the first place. Compute the system Directivity Index, Howard; we have the requisite data. Let's SEE it!

********

So, while I can see your point when it comes to the kind of speakers you prefer (heck, I even published an article in Stereo Review decades ago that pointed out the good points of both wide- and narrow-dispersion speakers), I continue to resent your insistant harping about how bad the AR-3a is, not to mention your misstating Allison's claims about the reverberant field and the limitations of his approach to speaker design.

I've never said any of that, Howard, NEVER. It's a straw man you've fabricated here for the purpose of your personal self-aggrandizement....

[Zilch]

My problem with you is not that directional speakers of the kind you prefer are no good, although all I have seen in the way of your preferences so far are that the GedLee speaker line is terrific. However, for all I know you do not even own those speakers, or if you do own them you do not have them installed in a decent room. You claim to have measured some AR and other speakers, but to do so properly (and here I am cutting you some slack and allowing for full system, direct-field measurements, in spite of the sonic pitfalls) would require both some rather good hardware and a rather good environment. You still have not posted any photos of much of anything, so for all I know you are making up your measurement claims. After all, you claim that your AR-3a curves mimic those Allison did in his 1970 analysis, and it would be easy to just redraw the curves and claim that you made measurements.

Genuinely insulting, Howard; you have outdone yourself with this.

I have provided not only the data, but also links to my work, and that of Geddes and Toole relating to this subject, and you refuse even to click and have a look.

I'm afraid there is no silver platter sufficiently grand upon which to serve a worthy tribute to your apparent boundless sense of self-importance here....

[soundminded]

Sniff Sniff. Hmm, smells like something's burning in here. Someone frying tweeters again? Someone cooking up fried egg tweeters and ham?

Zilch, have you ever thought about eliminating the room effect altogether by devising some stethescope like device with a big horn to collect sound from right in front of your speakers and piping it directly into your ears with tubing?

My speakers are as opposite from your ideal as I can get. My AR9s have 12 tweeters, 11 of them aimed away from me at the walls and ceiling and the one beamed forward at me is set down 6db. My Bose 901s have 6 tweeters, the only one pointing at me is also down 6 db from the others and they are all biamped with separate equalization. I've been re-engineering all of my speakers along those lines. That's why I recently bought about 150 more tweeters. They may be among the widest dispersing of high frequecy speaker systems for home music reproduction in the world. If what you said is valid, my speakers should sound horrible.

[Zilch]

If what you said is valid, my speakers should sound horrible.

I haven't said anything about how anything sounds.

Geddes said it.

You know where to find him.

Go give HIM what for....

[ar_pro]

Soundminded - would you care to post photos of your AR-9 tweeter arrangement?

I'd be very interested in seeing it.

[Shacky]

I haven't said anything about how anything sounds.

1) AR3a is not accurate by contemporary standards, rather, its “concert hall” coloration ...

5) AR3a's “max dispersion, flat power response” approach further proved self-defeating as means to achieve spectral balance in typical home listening spaces...

The reason AR3a's are deemed "dull" by many listeners is clearly shown: fully 75% of the "flat" power response is gone by 8 kHz, and an octave higher, at 16 kHz, it's down 90%; there's effectively nobody home above there in the living rooms studied.

[Zilch]

Thank you for contributing this nugget of profound insight into your understanding of the issue, Shacky....

[soundminded]

I haven't said anything about how anything sounds.

Geddes said it.

You know where to find him.

Go give HIM what for....

I'm not one to participate in whatever it is that caused these discussions to be moved out of the living room and into the kitchen (it could have been the back alley instead ) but Zilch, after all you've said, you can hardly disown the philosophy of using high directivity speakers to eliminate the effects of room acoustics as much as possible. It seems to me that has been your mantra from the outset which is why you championed Geddes design in the first place as I understood it. Unlike others here, I see no problem with someone with an alternative view to the philosophies behind the speaker designs most valued here presenting the best possible case for that alternate view. It's made for some interesting and lively exchanges. Don't get soft on us here now. I'd hate to see you switch sides midstream, Zilch say it isn't so.

I think your views represent the views of the overwhelmig majority of audiophiles and speaker manufacturers today. The first time I heard of such an approach was from the USSR back in the 70s and at that time it ran counter to what most of us believed. But then my goals are different from yours and those who share your views I think. You look at the listening room as a detriment to sound. Even in Allison and Berkovitz's paper, they called the room acoustics effect on spectral balance a "contaminent." Audiophiles and I think sound engineers fight the room. I concluded a long time ago, that's a hopeless battle you can't win. And the goal today for most of them for some reason seems to be some nebulous attribute called imaging. I'm not sure what that even is but it appears to have something to do with musical instruments appearing to have a pinpoint source spread across an apparently wide variety of horizontal angles and at varying distances. Everything else is sacrificed to achieve this one goal. (It may be the only goal they can achieve.) It's a goal which could hardly matter less to me. Where I usually sit in the cheaper seats towards the back (the seats I like best because I hear the most revereberation there) the angle between the musicians on the extreme left and right is usually less than +/- 45 degrees, often much less and all of the musicians are approximately the same distance from me. As I explained in other postings, as I see it, you can't reproduce the timbre of musical instruments at a concert from a sound reproducing system without reproducing other aspects of the acoustics as well. Therefore, my goal in this "conventional" type of sound system is to reproduce the sound of acoustic instruments as they would be heard in my own room as closely as possible (for which everything else including imaging is expendible.) Also, being trained as an engineer, I have been taught to think in terms of systems, not in terms of individual pieces of of equipment as I think most audiophiles do. Therefore, for me, one necessary function of a sound reproducing system is to be able to compensate for the variations of spectral balance from one recording to another. Given the vast differences I find from one cd to another in this regard, I don't see any alternative. In achieving this goal, I am also forced not only to take into account the listening room's acoustics but to make it an integral part of the design. In fact the success of my design depends on it and the larger and deader the room, the more expensive it becomes to engineer for it. In achieving this particular goal from the widest range of recordings, in this regard I'll put either of my two main systems up against anyone elses regardless of type or cost.

[genek]

I've been re-engineering all of my speakers along those lines. That's why I recently bought about 150 more tweeters.

What tweeters have you selected for this effort? Or are you personally responsible for the worldwide shortage of working vintage AR domes...?

[Zilch]

I'm not one to participate in whatever it is that caused these discussions to be moved out of the living room and into the kitchen (it could have been the back alley instead ) but Zilch, after all you've said, you can hardly disown the philosophy of using high directivity speakers to eliminate the effects of room acoustics as much as possible. It seems to me that has been your mantra from the outset which is why you championed Geddes design in the first place as I understood it. Unlike others here, I see no problem with someone with an alternative view to the philosophies behind the speaker designs most valued here presenting the best possible case for that alternate view. It's made for some interesting and lively exchanges. Don't get soft on us here now. I'd hate to see you switch sides midstream, Zilch say it isn't so.

I have repeatedly solicited participants here to define what they mean by "narrow" versus "wide" and "very wide" dispersion so as not to impose my own frame of reference on the discussion. Ignoring the vertical for the sake of clarity, and using the industry standard -6 dB as the measurement criterion (a concept with which many here appear to be unfamiliar), +/- 15° would be considered very narrow, and certainly "beamy." Are there speakers which conform to this limitation intentionally? Yes, very long throw horns are one example, and many tweeters such as JBL's familiar "bullet" are another. Look at the beamwidth vs. frequency curve, and it's clearly not constant directivity, and very narrow in the last octave. It's what I would consider illustrative of a "speakers as big headphones" driver which must be aimed at the sweet spot. Move to the end of the couch, and the highs go MIA:

http://www.jblpro.com/pub/obsolete/2402.pdf

Are there enthusiasts who like such a presentation in their listening rooms? Certainly. The room plays virtually no role, and spaciousness is limited to that generated by cues recorded in the program. In larger performance spaces, they are effectively deployed in arrays; your local "old school" disco may still have them, for example, but newer installations use constant directivity to accomplish the requisite full-spectrum audience coverage, with up to 360° uniform dispersion, instead:

http://www.jblpro.com/catalog/support/getf...2&doctype=3

I have posted the polar dispersion of that waveguide earlier in this thread, and it is easily seen how it might perform in such an array. Yes, there are two- and three-waveguide versions, as well.

+/- 30°, still "narrow" dispersion, in my view, with a 60° effective beamwidth, is more representative of the high-frequency dispersion capability common in front-firing cone/dome multi-way speakers. Toed-in to the listening position, the room contributes little to their performance, but firing front in parallel with sidewalls, lateral reflections come into play; if the distance to the wall is large, the reflections come from well off-axis, and are substantially attenuated. The delays are short, and the perception of spaciousness is not significantly enhanced, according to Toole's thesis. Constant-directivity waveguides with this horizontal dispersion pattern are commonly available, and it is indeed favored by "audiophiles."

+/- 45°, a 90° beamwidth, is considered "medium," or "moderate" dispersion, approaching "short throw" in sound reinforcement parlance, is most common, and few conventional drivers can accomplish it, hence Geddes' declaration that only waveguides get here effectively. Despite the widespread perception that AR3a is "wide dispersion," I have demonstrated above that it only barely achieves contemporary "moderate" dispersion criteria, and thus three or more mids and tweeters on angled baffles were required for AR to achieve truly "wide" dispersion, a fact apparently lost upon those vested in this myth. A 90° constant-directivity beamwidth may be effectively deployed in home listening spaces to produce a pleasing combination of precise imaging and perception of spaciousness with artificial ambience.

AR3a's high frequency response, substantially attenuated to simulate "concert hall" coloration, cannot approach contemporary performance standards, however, even with the controls set to "Max," as is clearly demonstrated by the measurements and Allison and Berkovitz's in-room power response findings. Those who desire a more "modern" sound are really asking for them to be redesigned, as I have earlier observed.

Wide dispersion begins at +/- 60°, in my view, with a 120° beamwidth, and is rarely achieved with constant directivity across the complete HF spectrum using a single driver. Toole and Geddes both argue that the early sidewall reflections it generates in typical home listening spaces are detrimental in many respects. Both further suggest that very wide hemispherical dispersion, +/- 90° and above, such as LST and Allison angled-baffle designs, is most suitably deployed as sidewall surrounds, appropriately delayed to artificially generate LEV envelopment cues in multi-channel home listening systems, clearly the realm of your expertise....

[Zilch]

What riles me, and I suppose riles you, too, is that some people here believe that they have proved that a really fine speaker is not particularly fine at all.

What riles you, Howard, is that your "old school" perspective on loudspeaker design has long since been discredited, indeed, repudiated, by science, the industry at large, and the marketplace, and that I have come here with the effrontery of saying so, with respect to which I reiterate the following salient points:

1) Nobody, least of all, me, has said that AR3a's are junk. You have overlaid what I have brought to this discussion with that, not to mention a bountiful array of ad hominem attacks, and your intent in doing so is obvious to all.

2) I have merely verified the findings of Allison and Berkovitz (1970) using modern measurement techniques, and offered up a contemporary perspective on what they might mean.

3) The Allison and Berkovitz paper does not say what you believe it does; in many respects, given an objective reading, it says very much the opposite, and certainly does not support your thesis. We have merely turned your interpretation on its head, here, not the work itself.

4) There is no point in continuing to recite the "live vs. recorded" mantra, when you have in fact conceded that most any quality loudspeaker could perform as well or better, as Allison himself has apparently told you. It is understandable that you would cling to this, as it's just about all you have left to substantiate your case.

If you would just set aside your personal bias and reread the paper, and Toole, and Geddes (if you have the stomach for it) as well, objectively, you just might discover what it is that you actually like about your Allisons....

[Zilch]

Are we implying here that Geddes might be wrong?

http://www.classicspeakerpages.net/IP.Boar...amp;#entry79301

Let's you and him fight.

Your analysis of the significance of the LVR demos presumes we are saying the speakers are junk. You made that up, Howard. They were what they were, which is all but meaningless with respect to the issues at hand.

I have posted Allison and Berkovitz's conclusions throughout this discussion, and they do not say what you contend.

Quote any conclusion, indeed, any statement, even, from the paper, which supports your primary thesis as to what it shows....

[Zilch]

You claim to have demonstrated that the AR-3a does not have wide dispersion much beyond the 45-degree angle point, but that claim makes no sense at all when you look at the driver curves the company posted in its brochures and that Allison illustrated in his article. Just where do you think that wider off-axis radiation is going once the drivers are in the box? Sure, there are diffraction effects, but you make it sound as if those effects basically blow away response out to wider angles, which is ridiculous.

It's GONE, Howard, only recoverable and measurable in AR's "special" highly reverberant chamber, which provided the imaginary system "frequency response" curves published in AR literature.

According to Allison and Berkovitz, what the listener actually hears is shown in the averaged eight living room power response curve, itself no less contrived than the LVR demos, since it is substantially boosted above the "normal" flat reverberant response, as I have stated, in which summary differentially boosted in-room power response curve, it is down 6 dB at 8 kHz and all but MIA at -10 dB an octave higher.

I asked you that very queston earlier, the flat "total energy" reverberant response, "Where'd it GO, Howard?"

"Dull," indeed, to most all contemporary listeners, even at "Max," very much like the concert hall, according to the paper....