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Some AR2ax measurements


speaker dave

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I want to interject some points, too. You and I are pretty much on the same wavelength, but I do want to clarify some things for other readers.

First, it was essential that the recordings be anechoically transcribed, because Villchur wanted the output from the speakers to be uncolored by hall or room acoustics. The live instruments were that way, and for the recorded sound to match them as closely as possible it was necessary for that sound to be uncolored by secondary reflections from the recording space. Commercial recordings do have hall reverb recorded along with the instruments, so as to have the playback sound decently mimic a live-music space. Unfortunately, with two-channel playback that hall acoustic sound is coming just from up front, which is one (out of many) reasons that no matter how good the speakers may be, using just two of them in a home-playback space cannot properly replicate a live-music experience. One problem that Zilch has is that he simply dismisses having any kind of live, acoustic instrument experience exist as a reference standard. For him, an audio system fed by recordings of pop-music studio transcriptions is basically a proto "musical instrument" all by itself.

Second, one of the most difficult things Villchur had to deal with involved the radiation patterns of the quartet instruments themselves. He had to locate his microphones in such a way that their direct-field outputs would mimic the respective omnidirectional output of the instruments in a playback space. He had to experiment considerably to get the spectral balances just right.

Third, Roy Allison has told me that to get the balance right in most of the playback locations the Dynaco preamp treble control had to be advanced so that the average high-frequeny level was increased by about 5 dB. This would allow the AR-3 systems to generate close to a flat power output over the audible range. Obviously, with most commercial recordings of the era (and even of our own era), the treble output of speakers playing classical music would have to be attenuated somewhat. Most audio buffs have a distorted idea of how instruments like violins sound in live, concert-hall performances. They sound muted, compared to the way they sound with most recordings played back on speakers with flat output in the upper midrange and treble.

Fourth, for me, the salient fact of the demos is that they proved Toole (and Zilch) wrong decades ago, long before either of those critics did their flawed research. Toole measured the AR-3 (with a curve series reproduced in his book), and commented upon its ragged direct-field output and the fact that his listening panel thought they sounded "dull". The speaker was dismissed by him as a good effort in its time, but hopelessly out of its class by modern standards. However, what Villchur did proved not only that the AR-3 was a superb speaker (admittedly, still not quite as good as the later 3a, LST, and Allison models), but also that Toole's measurement and analysis techniques for speaker performance are wrong headed in many ways. Ditto for Zilch.

Fifth, the AR-3 did not have as wide a radiation pattern as the AR-3a, and certainly not as wide as the LST and the Allison models, particularly those with dual angled front panels. Consequently, it would tend to beam more than those modelss and if Villchur adjusted the balance for the best overall spectral-balance duplication of the live performers the speaker might be a tad hot sounding on axis, at least from up close.

Sixth, Stereophile magazine will do whatever it takes to keep its subscriber base loyal. Given the types of people involved (both subscribers and contributors), your comments regarding the journal are on the mark.

Howard Ferstler

There is one point I think critical that I strongly disagree with you about;

" Most audio buffs have a distorted idea of how instruments like violins sound in live, concert-hall performances. They sound muted, compared to the way they sound with most recordings played back on speakers with flat output in the upper midrange and treble."

Muted does not characterize the sound of a violin at a live performance as I would characterize it. Steve F's response to what are the four elements of music were; "I remember this from years back: Melody, harmony, rhythm, and dynamics." Actually that turned out to get a lot of hits on a Google search, exactly in that order. Another that got a lot of hits substituted pitch for dynamics. But the way I learned it when I studied music in college (yes I took it as a humanities elective and I even had to write music including harmony) were; melody, harmony, tonality, and rhythm. Thinking about tonality in its broadest sense, timbre is only one part of it. Dynamics, that is loudness of tone is also part of tonality. Different pitches of tones are combined to create melody. The timbre of a musical instrument depends on several factors. The instrument itself, how it is played, the acoustics of the venue, and where both the performer and listener are located in the venue. Peter Nero, the now aged jazz/pop pianist gave an interesting interview about a year or two ago on NPR. He explaine how he'd arrive at the performance venue early in the day and he and his assistant would move the piano around on the stage looking for "the sweet spot" where it sounded best in the audience. Sometimes it was a matter of moving it a foot or even inches. Presumably, he hoped it wouldn't change once the audience came in and sat down. Violins are quasi omnidirectional radiators of sound. Sound coming directly from the strings constitutes very little of what you hear. You can discover this yourself in any music store by bowing an electronic violin without turning on the amplifier. What you'll be hearing is the contribution of the strings through direct radiation. Almost inaudible from just a few feet away. The rest of the sound comes from the resonant cavity within the violin (probably a Helmholtz resonator) where the sound escapes through the f holes and the sound from vibration of the body of the violin itself. The fact that the Guarnari del Gesu ex Kochanski had no trouble filling up the 900,000 cubic foot Carnegie Hall at a performance I attended where I sat far back in the orchestra level seats is testimony to how effective it can be. I sat closer when I attended Heifetz's performance, I was in the center of the orchestra seats, probably around row N. I was very familiar with the ex-Kochanski's sound having heard it many times in many places including my own home. It is remarkable that a violin can sound as loud as a trumpet, you would never think so. Tonality is one factor that differentiates great musical instruments, and performers including singers from all others. At least three elements always seem to be there among the best. Purity of tone is one, a complete absence of lack of clarity, there are no spurious sounds. Power is another. The seeming capacity for limitless power within the context of the music such that there is no sense of strain even in the loudest of passages and with no change in the quality of timbre. The third is nuance, the ability to produce subtle changes in the shading of timbre. And the ability to combine all three simultaneously. This alone disqualifies most musical performers as great artists. (there are other factors too.)

What does this have to do with the timbre of a violin? The first sound you hear comes from the instrument itself and from reflections off of nearby objects such as the floor, the podium, music stands. This sound is richest in harmonics. It has the initial sharp transient attack which characterizes its timbre. That sound is followed by a large number of echoes of this tone reaching your ears through many paths of reflection during a period over one or two seconds. Because they are sufficiently close in time, your brain integrates them with the origianal sound and makes a large number of judgements about the nature of the source, its distance from you, how powerful it is, and the size and nature of the space you are in. As the echoes of each note die out, not only do they get softer, but the relative content of high frequencies compared to low frequences diminishes. This is demonstrated by the fact that the RT of concert halls as a function of frequency is always lower at higher frequencies than at low and mid frequencies. This makes the subjective tone more mellow without detracting from its clarity or "muting" it. Therefore the timbre of a musical instrument is a dynamic event which occurs over time. Applying a steady state filter to alter all of the sound badly distorts it. The timbre cannot be seperated from the reverberant acoustics without substantially affecting it. Commercial recordings of violins like all instruments are made close to the instrument. The microphones are a small fraction of the distance from the instruments even at a recording in a hall than you'd be if you sat in the audience. The microphones are usually also directional and pick up predominantly the direct and early reflections. The proportion of later reflections that reaches the recordings is much lower than you'd hear. (This may explain in part why dynamically compressed phonograph records are more pleasing than uncompressed CDs. The reverberation at the end of each musical phrase is made louder.) Your speakers at home radiate virtually all of their high frequency sound directly at you while lower frequencies are radiated more omnidirectionally. What you hear is an initial shrill burst of high frequencies followed by echoes which have almost no high frequencies in them at all. That's the part that's muted. The sound of a violin heard in a concert hall cannot be duplicated at home by the types of recording and playback systems now in use. The audible difference to those familiar with the real thing is striking...and very disappointing.

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The first sound you hear comes from the instrument itself and from reflections off of nearby objects such as the floor, the podium, music stands. This sound is richest in harmonics. It has the initial sharp transient attack which characterizes its timbre. That sound is followed by a large number of echoes of this tone reaching your ears through many paths of reflection during a period over one or two seconds. Because they are sufficiently close in time, your brain integrates them with the origianal sound and makes a large number of judgements about the nature of the source, its distance from you, how powerful it is, and the size and nature of the space you are in.

One of the more unusual things I noted about the AR TOTL models I auditioned during the early 70's (3a, 5, 2ax; the LST was not available for demo yet at the time) was that turning the volume down on the demo amp didn't make the sound seem "softer" so much as it made it seem "more distant," as if I'd gotten up from a seat in row 10 and moved to the rear of a hall. This was an effect I never noticed in any ot the other speakers I listened to, including AR's own models lower down in the line, and I've never experienced it from any others I've heard since, including AR's ADD series and the 303. I do still hear it if I switch beteen the 3a's, 2ax's and 6's I have now, so I know it was not just some freak occurrence caused by a specific listening space.

It may have been some sort of contrived trickery, but if it was it was good contrived trickery.

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I want to interject some points, too. You and I are pretty much on the same wavelength, but I do want to clarify some things for other readers.

First, it was essential that the recordings be anechoically transcribed, because Villchur wanted the output from the speakers to be uncolored by hall or room acoustics. The live instruments were that way, and for the recorded sound to match them as closely as possible it was necessary for that sound to be uncolored by secondary reflections from the recording space. Commercial recordings do have hall reverb recorded along with the instruments, so as to have the playback sound decently mimic a live-music space. Unfortunately, with two-channel playback that hall acoustic sound is coming just from up front, which is one (out of many) reasons that no matter how good the speakers may be, using just two of them in a home-playback space cannot properly replicate a live-music experience. One problem that Zilch has is that he simply dismisses having any kind of live, acoustic instrument experience exist as a reference standard. For him, an audio system fed by recordings of pop-music studio transcriptions is basically a proto "musical instrument" all by itself.

Second, one of the most difficult things Villchur had to deal with involved the radiation patterns of the quartet instruments themselves. He had to locate his microphones in such a way that their direct-field outputs would mimic the respective omnidirectional output of the instruments in a playback space. He had to experiment considerably to get the spectral balances just right.

Third, Roy Allison has told me that to get the balance right in most of the playback locations the Dynaco preamp treble control had to be advanced so that the average high-frequeny level was increased by about 5 dB. This would allow the AR-3 systems to generate close to a flat power output over the audible range. Obviously, with most commercial recordings of the era (and even of our own era), the treble output of speakers playing classical music would have to be attenuated somewhat. Most audio buffs have a distorted idea of how instruments like violins sound in live, concert-hall performances. They sound muted, compared to the way they sound with most recordings played back on speakers with flat output in the upper midrange and treble.

Fourth, for me, the salient fact of the demos is that they proved Toole (and Zilch) wrong decades ago, long before either of those critics did their flawed research. Toole measured the AR-3 (with a curve series reproduced in his book), and commented upon its ragged direct-field output and the fact that his listening panel thought they sounded "dull". The speaker was dismissed by him as a good effort in its time, but hopelessly out of its class by modern standards. However, what Villchur did proved not only that the AR-3 was a superb speaker (admittedly, still not quite as good as the later 3a, LST, and Allison models), but also that Toole's measurement and analysis techniques for speaker performance are wrong headed in many ways. Ditto for Zilch.

Fifth, the AR-3 did not have as wide a radiation pattern as the AR-3a, and certainly not as wide as the LST and the Allison models, particularly those with dual angled front panels. Consequently, it would tend to beam more than those modelss and if Villchur adjusted the balance for the best overall spectral-balance duplication of the live performers the speaker might be a tad hot sounding on axis, at least from up close.

Sixth, Stereophile magazine will do whatever it takes to keep its subscriber base loyal. Given the types of people involved (both subscribers and contributors), your comments regarding the journal are on the mark.

Howard Ferstler

Of course! This makes a lot of sense to me. The demo wasn't meant to show that a live performance could be accurately recorded in the hall itself then accurately played back in a way that didn't duplicate the hall's effects on that same sound. It was to demonstrate the speakers ability to deliver a tone correct performance to the original instruments.

So of course you'd have to mic/record it differently.

Brilliant!

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One of the more unusual things I noted about the AR TOTL models I auditioned during the early 70's (3a, 5, 2ax; the LST was not available for demo yet at the time) was that turning the volume down on the demo amp didn't make the sound seem "softer" so much as it made it seem "more distant," as if I'd gotten up from a seat in row 10 and moved to the rear of a hall. This was an effect I never noticed in any ot the other speakers I listened to, including AR's own models lower down in the line, and I've never experienced it from any others I've heard since, including AR's ADD series and the 303. I do still hear it if I switch beteen the 3a's, 2ax's and 6's I have now, so I know it was not just some freak occurrence caused by a specific listening space.

It may have been some sort of contrived trickery, but if it was it was good contrived trickery.

They are the best damn low level listening speakers I've ever listened to. You don't have to crank them to get a nice bass bloom.

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