Some AR2ax measurements

[soundminded]

ARs marketing share existed when their were several "audiophile" companies trying to create "great" speakers.

Though I don't believe I am, IF I am confusing science with marketing, you seem to be "proving with science" something that apparently doesn't correlate to real listening/hearing. The only conclusion that I can come up with is that the science - which you may understand very well - is wrong for the application. It's like the old aerodynamic proof that bumblebees can't fly. Well, on paper, according to "the science" they can't. But somehow they manage it quite well. So when science disagrees with reality, the science involved isn't worth much, regardless of how much work has gone into it.

So if your "science" says that my AR3As/LSTs don't sound good/accurate/realistic, whatever, and my ears say they do, how do I make my ears hear (apologies to Simon and Garfunkel) the "Sounds of Science" instead of the sounds of reality?

"The only conclusion that I can come up with is that the science - which you may understand very well - is wrong for the application."

That is the correct conclusion. Despite what many would like to think, the science of acoustics is still at a very primitive stage as is the science of psychoacoustics. There is much more to be learned than is already known. To hear manufacturers, speaker scientists, magazine pundits, and others tell it, you'd think they had all the answers already when in fact their real knowledge is so inadequate that they cannot explain why two speakers which measure similarly according to their methods sound so different. Then add to that the fact that they all have something to sell and you'll know why every month, the magazines have the next "best speaker in the history of the world" featured among their reports. You have to give them credit though, they've managed to recycle the same story for many decades and people still buy it.

[Shacky]

Perhaps you would be well served by spending $168, also....

http://www.audiokarma.org/forums/showthrea...142#post2528142

I'm beginning to think you have a personal stake in the econowave or driver market that you promote. Can you provide some proof that is not true?

[genek]

So if your "science" says that my AR3As/LSTs don't sound good/accurate/realistic, whatever, and my ears say they do, how do I make my ears hear (apologies to Simon and Garfunkel) the "Sounds of Science" instead of the sounds of reality?

You don't. You either conclude that the science is faulty, or that it does present a statistically valid profile of what most people regard as "good" today and accept that you are a nonconformist. Personally, I'd opt for the second.

As far as AR's former market share is concerned, the company's ability to produce products that pleased customers has to share credit with the company's incredibly customer-friendly warranty policies and its decision not to invoke its power under the "fair trade" laws of the period to prevent its dealers from discounting. When presented with a choice between two speakers listing at $199, one of which couldn't be discounted and the other that could be bought for $120, many customers may have decided that 2nd choice was "good enough."

It is conceivable that if there was still a large-sized two-channel audiophile market there might still be people lining up on opposite sides of the "East Coast/West Coast" divide in listener preference, and that speakers with classic AR sound might still find enough of a customer base to justify their manufacture, but probably not by a company of any size; Teledyne certainly didn't waste much time after Villchur left the building before they started pushing the product line toward the brighter sound demanded by "the market." And if I visit the few two-channel audiophile stores that are left around here, there are about as many JBL's in the listening rooms as there are classic ARs. The preference in those stores seems to be for everything so relentlessly "accurate" and untunable that an LP's ticks and pops are regarded with as much reverence as the actual content.

[Zilch]

Though I don't believe I am, IF I am confusing science with marketing, you seem to be "proving with science" something that apparently doesn't correlate to real listening/hearing. The only conclusion that I can come up with is that the science - which you may understand very well - is wrong for the application.

http://www.aes.org/e-lib/download.cfm?ID=1...amp;name=harman

It's like the old aerodynamic proof that bumblebees can't fly. Well, on paper, according to "the science" they can't. But somehow they manage it quite well. So when science disagrees with reality, the science involved isn't worth much, regardless of how much work has gone into it.

Myth.

Science ultimately determined how bumblebees fly, and the principles have found application outside the realm of insects:

http://en.wikipedia.org/wiki/Bumblebee#Bumblebee_myths

So if your "science" says that my AR3As/LSTs don't sound good/accurate/realistic, whatever, and my ears say they do, how do I make my ears hear (apologies to Simon and Garfunkel) the "Sounds of Science" instead of the sounds of reality?

Science does not say that, rather, merely that it may not do quite so good a job of it as you suppose, and if so, there is room for improvement....

[genek]

Sorry, never did. I think I have some data for that hall in an ASA publication. I think it was renovated at one point. If I find it and it looks interesting, I'll report anything unusual about it.

Davies Hall was built in 1980, and if you followed up the SF Symphony's last performance in the old War Memorial Opera House with its first night at Davies, the difference in sound was glaring and appalling. They remodeled it in 1992, and after that people started touting it as "world class." All I can say is, it did get better.

[Zilch]

Science is here to serve the audiophile consumer.

Nope, science is here to serve the industry, and has in large part answered its inquiry.

It is also available to anyone willing to pursue its teachings, and has been for over a century.

The truce I offered is hereby withdrawn

You broke the alleged "truce" within hours of committing, and then could not fathom why that might upset me. I do, however, recall it prominently featuring the word "unilateral," and that no agreement on my part was even required. You are a man of your word, for sure.

I'm beginning to think you have a personal stake in the econowave or driver market that you promote.

Only if you prefer having a PC boards on which to construct the crossovers, for which I charge the incredible sum of $20 per pair, including postage within the USA.

Who knows but that you won't one day be sending some cash my way.

[in advance, of course.... ]

[Mexicomike]

Science ultimately determined how bumblebees fly, and the principles have found application outside the realm of insects:

YES, it ULTIMATELY did. But initially it did not. Once they corrected/perfected the science, THEN it proved the reality. Same thing...your science MY at some point be corrected to do what you claim it does. For now, it does not.

[soundminded]

Davies Hall was built in 1980, and if you followed up the SF Symphony's last performance in the old War Memorial Opera House with its first night at Davies, the difference in sound was glaring and appalling. They remodeled it in 1992, and after that people started touting it as "world class." All I can say is, it did get better.

Looks like another one of Leo's fiascos. Yes, it was built in 1980 at a cost of 27 million dollars. It seated 3000. Here's how it was advertised;

"The 3000 seat concert hall was deisgned to provide "a perfect instrument for the presentation of symphonic music. Any other uses are of secondary importance......" The ceiling is a 6" concrete slab. The walls are multifaceted precast concrete 4"thick. The balcony fronts and soffits are 2" thick plaster. The front row of the first balcony is only about 85 feet from the conductor. The most remote seat in the upper balcony is 135 feet away.

Mid frequency reverberation time in the occupied hall can be varied from 1.6 to 2.2 seconds with retractable velour banners.

The empty hall RT data with no banners is as follows;

63hz=4.0

125=3.5

250=3.3

500=3.1

1k=3.0

2k=2.6

4k=2.15

8k=1.5

Empty with all banners extended

63=3.35

125=2.8

250=2.2

500=2.0

1k=1.9

2k=1.8

4k=1.5

8k=1.1

The ILG fan response with the microphone in the center loge and the fan on stage shows referenced to 1khz response

0 hz 0db rising to a peak at 63 hz of 10 to 12 db, falling to about the reference point at 125hz, flat to 1khz with all banners in use, 2khz with no banners in use. There are inflection points at those frequencies and falling linearly to about -11 db at 8khz with no banners, -14db at 8 khz with all banners.

Noise Criteria is NC 13 (remarkable.)

It appears to me that in the rear of the orchestra seats there could be considerable acoustic shadow due to the large balcony area.

I don't think this hall was even considered in Beranek's comparison of 59 halls in his white paper and he didn't mention it in his Geugenheim Lecture at the Mechanical Engineering Department at Georgia Tech in 2001.

The shape is rather unusual. The front looks like a truncated pie wedge but there is a transition to a circular area which comprises most of the audience. Visual and acoustic intimacy were the design objectives.

The fact that it was renovated in 1992 only 12 years after it was completed does not speak well of its acoustical design success.

[Zilch]

YES, it ULTIMATELY did. But initially it did not. Once they corrected/perfected the science, THEN it proved the reality.

You offered up myth as an argument; there's an obvious trend in evidence here.

Same thing...your science MAY at some point be corrected to do what you claim it does. For now, it does not.

I presume you have not read, nor are you going to read, the link to the Toole paper I provided, especially for you....

[Zilch]

AR3a polars as discussed in Post #162, above, per Allison (1972), 0° - 75°, equivalent of 0° - 150° effective beamwidth, with cabinet edge diffraction effects masked by 2-Pi measurement alignment:

Fig. 6 - Full-Range Horizontal (unknown direction)

Fig. 7 - Full-range Horizontal (opposite direction)

Without grille molding, its diffraction effects additionally not shown:

Fig. 3 - Tweeter

Fig. 2 - Midrange

Compare to my measurements posted here, made nearly 40 years later.

Pop quiz: Is Fig. 6 inboard or outboard? How can we tell?

[soundminded]

You offered up myth as an argument; there's an obvious trend in evidence here.

I presume you have not read, nor are you going to read, the link to the Toole paper I provided, especially for you....

Thanks for the link to Toole's paper. I've read the first and last parts of it so far and these are very similar or identical to conclusions I've come to myself (haven't experimented with 4 subwoofers though.) So far nothing of signifigance I can disagree with. The paper's only problem....it doesn't go nearly far enough. Its scope is far to restricted, it doesn't look at the bigger picture. Interesting how Beranek and Toole came to the same conclusion about IACC independently. For Beranek, it is the number one consideration, bass is number 2. There are a lot of excerpts I could quote so far that are virttually identical to things I've posted here such as;

"It appears that much of what we perceive in terms of

sound quality can be predicted by the anechoic characterization

of loudspeakers. Because most of these data pertain

to sounds that reach listeners by indirect paths, it is proper

to suggest that nothing in those indirect sound paths

should alter the spectral balance."

(Page 18)

Yet in Toole's best commercial effort, Revel Salon Ultima, there is no engineered provision to compensate for the fact that all rooms surface reflections are frequency selective. As the data for Davies Hall above shows, this is true even for a material as hard as concrete. I've been experimenting with solutions to this problem for about 20 years with good results especially for AR9 and Bose 901. I've been re-engineering every speaker system I own to compensate for it.

[Mexicomike]

I hear with my ears, not with my eyes. Reading a paper does not affect my hearing; however reading Wikipedia as a source of factual information DOES affect my stomach. Anybody can write anything they want. I found a case where a writer in a forum...no, not this one...changed a wiki article to reflect what he had written in the forum. He wrote the forum "response" and, a few minutes later, changed the wik article (on boat engine room air intake area) to fit what he posted.

I offered up what WAS once considered a scientific fact. In fact, the bumblebee can't fly example was used with references in several international aviation conventions by US representatives in the mid 1990's to illustrate how the "mathematics" of operational aircraft deviation calculation did not coincide with the reality. Revisions were subsequently made to the collision risk formulas. I suggest that you need to determine why your science does not reflect reality and make similar revisions.

I think we have done this to death and I am certainly guilty of prolonging this thread to no point whatsoever. It certainly isn't going to help anyone who is interested in buying/preserving AR speaker. As another poster noted, it's probably an indication that I am spending too much time on the internet.

[Zilch]

Thanks for the link to Toole's paper. I've read the first and last parts of it so far and these are very similar or identical to conclusions I've come to myself (haven't experimented with 4 subwoofers though.) So far nothing of signifigance I can disagree with. The paper's only problem....it doesn't go nearly far enough. Its scope is far too restricted, it doesn't look at the bigger picture.

It's an abstract of his book, which deals with many of the issues of apparent interest to you more comprehensively.

"It appears that much of what we perceive in terms of

sound quality can be predicted by the anechoic characterization

of loudspeakers. Because most of these data pertain

to sounds that reach listeners by indirect paths, it is proper

to suggest that nothing in those indirect sound paths

should alter the spectral balance."

(Page 18)

Yet in Toole's best commercial effort, Revel Salon Ultima, there is no engineered provision to compensate for the fact that all rooms surface reflections are frequency selective. As the data for Davies Hall above shows, this is true even for a material as hard as concrete. I've been experimenting with solutions to this problem for about 20 years with good results especially for AR9 and Bose 901. I've been re-engineering every speaker system I own to compensate for it.

There is no reverberant field in small rooms; they are not Sabine spaces. In large measure, it's only the early reflections that matter. As indicator, you can kill virtually the entire soundfield spaciousness by damping the first-order reflections. Use a mirror to find them.

The same erroneous premise leads you to conclude that the constant-directivity waveguide polars I posted above indicate it is not well-suited for Hi-fi use.

I was hoping Howard would tell us whether he considers those curves to be "flat" or not, and disclose his criteria for wide versus narrow dispersion....

[soundminded]

It's an abstract of his book, which deals with many of the issues of apparent interest to you more comprehensively.

"It appears that much of what we perceive in terms of

sound quality can be predicted by the anechoic characterization

of loudspeakers. Because most of these data pertain

to sounds that reach listeners by indirect paths, it is proper

to suggest that nothing in those indirect sound paths

should alter the spectral balance."

(Page 18)

There is no reverberant field in small rooms; they are not Sabine spaces. In large measure, it's only the early reflections that matter. As indicator, you can kill virtually the entire soundfield spaciousness by damping the first-order reflections. Use a mirror to find them.

The same erroneous premise leads you to conclude that the constant-directivity waveguide polars I posted above indicate it is not well-suited for Hi-fi use.

I was hoping Howard would tell us whether he considers those curves to be "flat" or not, and disclose his criteria for wide versus narrow dispersion....

"There is no reverberant field in small rooms; they are not Sabine spaces."

The first part is not true. This is easy to prove....in any tiled bathroom. Sing in the shower and see.

Small rooms are not Sabine spaces. This is true. Sabine discovered in research for designing a new home for the Boston Symphony Orchestra which was Boston Symphony Hall that there is a direct correlation between the Reverberation time, the volume of the space, and the coefficient of absorption. This mathematical relationship apparently breaks down for small rooms, that's all that statement means.

[Zilch]

I suggest that you need to determine why your science does not reflect reality and make similar revisions.

Science has been asleep at the wheel for the last forty years, in your view. I posted the current thinking of a leading researcher in the field, and you apparently choose not to read or understand it; it has no relevance to your personal subjectivist reality.

I think we have done this to death and I am certainly guilty of prolonging this thread to no point whatsoever. It certainly isn't going to help anyone who is interested in buying/preserving AR speaker.

No? It has already helped in significant respects. My own work has answered several questions of specific interest to this forum:

Q1: Have the AR3a tweeters deteriorated over the years as many suppose?

A: Not very much, actually, though there is some evidence of aging.

Q2: How come they don't have the "brightness" they once did?

A: They never had it; the design has rolled-off highs to mimic "concert hall" performance.

Q3: Not even if I turn the level controls to "Max?"

A: Nope, can't get there with that; the tweeters simply do not have the output capability to provide the HF balance you're looking for.

Q4: My pots have corroded over the years; if I replace them with L-pads, will that help?

A: L-pads with a 25-Ohm parallel resistor as designed by CSP's RoyC are a spot-on replacement for the stock pots in the attenuation ranges of interest, both for the midrange and tweeter.

Q5: I still want more highs, can I get them with biamping providing more power to the tweeters?

A: Yes, substantially as Jerry (CSP's Onplane) advises, though he cautions that driving them harder may accelerate their deterioration, particularly if your intent is to crank these like West Coast rock speakers.

Q6: If I blow out the vintage tweeters, I can just replace them with new ones, right?

A: Well, maybe; we're working on that. There is speculation that no modern tweeters can replicate the dispersion characteristics of the originals, but it's thus far indeterminate whether this is either true or as significant as many enthusiasts presume.

Q7: What, then? I'd like a more "contemporary" HF balance, but I certainly don't want to reduce the resale value of these with a bunch of mods.

A: Remove the stock tweeters, store them safely away for reinstallation upon resale, and put in CSP's best recommended replacement that achieves your purpose.

Q8: What if that requires a crossover mod?

A: Shut up and do it; it can be "undone" when you decide to cash out.

Q9: I guess I like them the way they are, after all.

A: Cool. Carry on, then....

[Zilch]

"There is no reverberant field in small rooms; they are not Sabine spaces."

The first part is not true. This is easy to prove....in any tiled bathroom. Sing in the shower and see.

Indeed, the equivalent of AR's reverberant chamber used to implement their design concept. Alas, our showers are not listening spaces, an no one would rationally conclude that providing such reflectivity would be desirable.

Small rooms are not Sabine spaces. This is true. Sabine discovered in research for designing a new home for the Boston Symphony Orchestra which was Boston Symphony Hall that there is a direct correlation between the Reverberation time, the volume of the space, and the coefficient of absorption. This mathematical relationship apparently breaks down for small rooms, that's all that statement means.

More significantly, neither is the Beranek model applicable to small rooms; do the marshmallow experiment, and see for yourself....

[Mexicomike]

"No? It has already helped in significant respects. My own work has answered several questions of specific interest to this forum:"

LOL!

Is a pic of you on Wikipedia next to the term "Legend in his own mind?"

[onplane]

Q1: Have the AR3a tweeters deteriorated over the years as many suppose?

A: Not very much, actually, though there is some evidence of age.

Q2: How come they don't have the "brightness" they once did?

A: They never had it; the design has rolled-off highs to mimic "concert hall" performance.

Q3: Not even if I turn the level controls to "Max?"

A: Nope, can't get there with that; the tweeters simply do not have the output capability to provide the HF balance you're looking for.

Q4: My pots have corroded over the years; if I replace them with L-pads, will that help?

A: L-pads with a 25-Ohm parallel resistor as designed by CSP's RoyC are a spot-on replacement for the stock pots in the attenuation ranges of interest, both for the midrange and tweeter.

Q5: I still want more highs, can I get them with biamping providing more power to the tweeters?

A: Yes, substantially as Jerry advises, though he cautions that driving them harder may accelerate their deterioration, particularly if your intent is to crank these like West Coast rock speakers.

Q6: If I blow out the vintage tweeters, I can just replace them with new ones, right?

A: Well, maybe; we're working on that. There is speculation that no modern tweeters can replicate the dispersion characteristics of the originals, but it's thus far indeterminate whether this is either true or as significant as many enthusiasts presume.

Q7: What, then? I'd like a more "contemporary" HF balance, but I certainly don't want to reduce the resale value of these with a bunch of mods.

A: Remove the stock tweeters, store them safely away for reinstallation upon resale, and put in CSP's best recommended replacement that achieves your purpose.

Q8: What if that requires a crossover mod?

A: Shut up and do it; it can be "undone" when you decide to cash out.

Q9: I guess I like them the way they are, after all.

A: Cool. Carry on, then....

Hi, Zilch!!!

I haven't been following this thread due to its length. Nevertheless, I just loved your Q & A. You covered a lot of territory in a very short, concise and IMO accurate manner.

Nice work!!

Regards,

Jerry

[soundminded]

Indeed, the equivalent of AR's reverberant chamber used to implement their design concept. Alas, our showers are not listening spaces, an no one would rationally conclude that providing such reflectivity would be desirable.

More significantly, neither is the Beranek model applicable to small rooms; do the marshmallow experiment, and see for yourself....

""There is no reverberant field in small rooms; they are not Sabine spaces."

The first part is not true. This is easy to prove....in any tiled bathroom. Sing in the shower and see.

Indeed, the equivalent of AR's reverberant chamber used to implement their design concept. Alas, our showers are not listening spaces, an no one would rationally conclude that providing such reflectivity would be desirable."

If what you said were true, all anyone would ever hear out of a Bose 901 is what comes out of the front driver. There would also be no standing waves at low frequencies, no room resonances whatsoever. RT would be zero. If RT=0.5 seconds, a sound at 85 decibels would bounce back and forth along the length of a 20 foot room 27 times before it decays to 25 decibels [1090/(2*20)] (That's 13.5 round trips.) A typical room has about 10 million resonant frequencies in the audible range, any room.

[Zilch]

If what you said were true, all anyone would ever hear out of a Bose 901 is what comes out of the front driver. There would also be no standing waves at low frequencies, no room resonances whatsoever. RT would be zero. If RT=0.5 seconds, a sound at 85 decibels would bounce back and forth along the length of a 20 foot room 27 times before it decays to 25 decibels [1090/(2*20)] (That's 13.5 round trips.) A typical room has about 10 million resonant frequencies in the audible range, any room.

You are misinterpreting what I said. I did not say there were no reflections, rather, that the Beranek reverberant field, cornerstone and linchpin of Allison's analysis of AR3a design, does not exist in typical listening rooms.

At the time, both Bose and AR were singing the same reverberant field tune; by 1975, however, Holt knew more and better, and provided a modern analysis of what's actually going on, which Toole and other researchers refined over subsequent years into a cohesive synthesis of how loudspeakers and rooms interact:

http://www.stereophile.com/historical/425/index1.html

The artificially expanded apparent source width (ASW) which we all enjoy derives in its virtual entirely from first-order lateral reflections, not an imaginary reverberant field, and the second major element of spaciousness, listener envelopment (LEV) cannot be generated in small rooms other than via multi-channel simulation providing the requisite delays, your apparent area of expertise.

What we like about ARs is not what Villchur and Allison thought they were incorporating at the time, rather, an artifact of it, and with that understanding, we can very likely do it better, once we get past the erroneous assumption that they knew what they were doing. They didn't. There was no roadmap for their empirical innovations; they wrote the book, and some of it was apparently, if not now obviously, wrong....

[Shacky]

"No? It has already helped in significant respects. My own work has answered several questions of specific interest to this forum:"

LOL!

Is a pic of you on Wikipedia next to the term "Legend in his own mind?"

I was thinking exact same thing! It's incredible. We can't get a glimpse of his speaker LISTENING preferences. But we sure have seen how big his ego is. I may not be the sharpest tool in the shed on audio theory. But I do know BS when I see it. Wading through this thread requires some pretty high water boots for sure

[Pete B]

I've certainly had my disagreements with Zilch, however he is technically

correct. Why can't you "fans" accept that it is all right to like a flawed

design, nothing is perfect after all - it doesn't have to be. Liking them

does not make the marketing hype valid or correct.

I studied audio under a professor who's emphasis was the study of noise

control. You probably don't want to hear what he had to say about AR,

he did give credit for the acoustic suspension design, however he could

not use the 3a or 2ax for his studies as it was impossible to set levels

and hold them due to thermal compression and tweeter burn out. Now I

can already hear the replies that they were not designed for continuous

use like that, however with all the hype by AR about them one would

expect better results.

[Pete B]

I was thinking exact same thing! It's incredible. We can't get a glimpse of his speaker LISTENING preferences. But we sure have seen how big his ego is. I may not be the sharpest tool in the shed on audio theory. But I do know BS when I see it. Wading through this thread requires some pretty high water boots for sure

What does his taste in equipment have to do with pointing out technical

flaws in a design and defending his position? Obvioulsy, you're hoping

to attack him based on his taste which has nothing to do with the facts.

Surely you are aware that this is not allowed in the rules of debate.

Here, I'll bite. I'll put PSB Stratus Golds up against AR-3a's, 11's, 10pi's,

or the AR-LST. Not a fair comparison against AR-9's given the dual 12"

woofers.

I'll put my own design up against 9's, any day, as long as the amp is able

to comfortably drive 2 ohm loads - and 1 or 2 KW would be about right.

[Zilch]

Obviously, you're hoping to attack him based on his taste, which has nothing to do with the facts.

Y'know, folks, Pete and I have had knock-down drag-out battles over technical matters so nasty that threads have been shut down because they got too hot from us holding each others' feet to the fire.

Here's what also: I'm proud to call him "Friend."

Ad hominem has no place in this; it merely says you've run out of reasoned argument.

What some don't yet get is that I'm not attacking anything here; the purpose is to figure ARs out, technically, and whether anybody likes them or not, or whatever else they might prefer, has nothing to do with any of it. Go ask Geddes what he likes, or even for his opinion about particular speakers -- he won't tell you, because it's irrelevant to what he does.

I just read the latest Stereophile "As We See It" Shacky's been hyping of late as substantiation of his position:

http://www.stereophile.com/asweseeit/how_h...u_want_your_fi/

So, Stereophile's gonna fold?

Like Carl says, it IS about the music, and that's what we're doing here, bottom line. Like whatever you like to deliver it whichever way you like it, but that has nothing to do with this, and if anyone is offended by the discourse, they need only look to themselves for the reason(s).

[genek]

Why can't you "fans" accept that it is all right to like a flawed

design, nothing is perfect after all - it doesn't have to be. Liking them

does not make the marketing hype valid or correct.

There are basically two kinds of people hanging on to 40-year old audio equipment.

Some of us bought the stuff when it was new and our tastes have just never changed; we know the world has passed us by, and are pleased as all hell that we've lasted long enough to become living relics of a bygone age and that someone has gone to the effort to preserve all this wonderful memorabilia for us online.

And then there are those who discovered the stuff more recently. You've heard the old saw about new converts and fanaticsm?