Have you noticed that certain high-end audio magazines publish only weak, unconvincing letters of criticism and, on the other hand, always the strongest letters of praise? They obviously want you to think that you are getting a scrupulously fair, balanced sampling of reader opinion. But write them a highly articulate, authoritative put-down that makes them look incompetent or insincere, and they will suppress it. This journal is of a different persuasion. We are not impressed by groupie flattery and we welcome intelligent disagreement, no matter how strong. Try us. Letters printed here may or may not be excerpted at the discretion of the Editor. Ellipsis (...) indicates omission. Address all editorial correspondence to the Editor, The Audio Critic, P.O. Box 978, Quakertown, PA 18951.

The Audio Critic:

I read with great interest your review of Bob Carver's t-mod "Silver Seven" clones. I have seen laboratory data on one pair of Silver Sevens-a pair which may have been defective-but I have neither measured nor auditioned any of the t-mods, so I am not prepared to comment on Mr.

Carver's success in duplicating the output of his big tube amp. I would, however, like to address your comments on the wisdom of Carver attempting to replicate the "tube sound." You state that the output of an audiophile tube amplifier is characterized by high output impedance (over one ohm), a bit of second harmonic distortion, and abrupt rises in distortion at the frequency extremes. These observations are very generally correct but are not universally true.

That they should apply at all is a consequence of the design deficiencies in most currently produced tube power amps rather than of the inherent limitations of vacuum tube circuits themselves.

Most of the performance limitations in tube amplifiers made today are attributable to the single-ended circuitry used in the main gain stage and the plate-coupled topologies used in the output stages, as well as to the output transformers themselves.

Let us first consider the matter of output impedance. If, for instance, a unity coupled output stage, or a pure cathode follower or a totem pole (series-connected output stage), is employed in conjunction with a correctly designed output transformer, the output impedance can be brought to well below one ohm. I hasten to add that this is not mere theorizing on my part. Unity-coupled amplifiers are currently manufactured by Nestorovic, EAR, and Vacuum State Research, and were formerly made by McIntosh. In all cases, output impedance is or was a fraction of an ohm. A pure cathode-follower output constructed with volt age-regulator-type tubes such as the 6336, 7242, or 6AS7 might practically achieve an output impedance of a quarter of an ohm or even a tenth of an ohm. I can cite no production examples of this type, but a cathode-follower amplifier is available on a special-order basis from Vacuum State Re search. A transformer-coupled totem pole output would also yield an extremely low output impedance, though here again a commercial application appears never to have been attempted.

Why have transformer-coupled pure cathode followers or totem poles not been commercially produced? Probably because of their high drive requirements, which simply can't be met with the single-ended voltage amplifying circuitry that has al ways prevailed in the vacuum-tube realm.

With differential circuitry, totem pole or cathode follower outputs are entirely practical, and amplifiers using such output stages do yield low output impedance and good damping. As you're undoubtedly aware, both totem poles and pure cathode followers have been used in commercially produced OTL designs, but that needn't concern us here because OTLs do not have low output impedances.

More important, such unorthodox output stages make possible extremely wide band power delivery without the rising distortion at frequency extremes which you mention. Ordinary plate-coupled tube amplifiers require primary impedance loads in the thousands of ohms and thus critically high turns ratios to achieve good matching to conventional loudspeakers. Even at low power, power bandwidth is inevitably limit ed by shunt capacitance and leakage inductance in the transformer, but the problems become critical as output approaches and exceeds the 100-watt mark. It is worth noting that until the seventies nobody manufactured a plate-coupled consumer tube amplifier of over 100 watts output. The only consumer tube amps in the 200-300 watt range were the big Macs, which were all unity-coupled (half in the cathode circuit, half in the plate).

With an output stage having a low output impedance before transformation, a transformer can be designed that has extremely low distortion and phase shift in the audio band, and extremely extended frequency response. If, for instance, your primary impedance is 100 ohms, you can get a secondary impedance of 0.1 ohm with a very low turns ratio. Indeed, if the amp is designed with split supplies, an autoformer can be utilized in lieu of a conventional transformer for an almost total elimination of shunt capacitance and leakage inductance. I won't belabor the point. A tube output stage with an inherently low output impedance working into a well-designed transformer will give transistor amps a pretty good run for the money in terms of damping and bandwidth.

I am not implying that those who design plate-coupled amplifiers are fools. Plate coupling makes for simpler, cheaper de signs and a much wider choice of output tubes. And it can work extremely well in low-powered units. But today's audiophile wants high power, and I am convinced that plate coupling is not the way to go. And I'm in pretty good company. Frank McIntosh felt the same way.

I might mention in passing that the bandwidth of a plate-coupled tube amplifier can be considerably improved by using a pair of output transformers in parallel, each optimized for one half of the frequency range. It's an old trick, and I believe that Carver uses it on the Silver Seven. Double transformers are also used on the new Cary amps and were used on the now discontinued Meitner tube amps. I don't think the scheme works as well as a pure cathode follower, and it's certainly not cost-effective.

You mention distortion. Not all tubes produce a preponderance of second harmonics. Most triodes do, but pentodes tend to produce a more transistor-like distortion spectrum with plenty of high-order nasties (pentodes were regularly denounced as output devices in 1940°s consumer publications). Now, if an all-triode power amp--the preferred design in my opinion-is made fully differential, most of that second harmonic will be bucked out. Operate the gain stages class A and use judicious amounts of feedback, and the small amount of third harmonic will be just about eliminated also. In fact, the active circuitry of a fully differential all-triode tube amp may be designed to produce practically no THD at all, and with values of global feedback many, many dB less than would be required to achieve similar results with a solid-state design. Interestingly, the fully differential all-triode Morikawa amp from Japan has THD in the 0.01% range with a mere 6 dB of global feedback, and most of that distortion is probably due to the output transformer.

Of course, one may object-why bother with tubes when vanishingly low THD values can be achieved with transistors? In other words, what particular merit is there to tube design today? I think you can gather by now that I still favor vacuum tubes, and that being the case, I wish I could make an irrefutable technical case for their superiority and for the impossibility of a solid-state amp perfectly replicating the transfer function of a properly designed tube amp. I'm afraid I can't settle the matter, but I can state a number of reasons why a tube amplifier should outperform a solid-state type in re producing music.

The better audio-frequency triodes produce negligible distortion above the third harmonic even at full clip. Bipolar transistors produce a relatively unfavorable harmonic spectrum, especially at clipping, and heavy use of global feedback exacerbates the problem by eliminating low-order distortion while leaving higher-order products. (MOSFETs are a special case; they have a somewhat tube-like distortion spectrum, but total distortion is quite high, and they're hard to drive, especially in multiples.) Class A operation does linearize transistors considerably in this respect but doesn't completely solve the problem, in as much as class A transistor amps derate when operated into low-impedance and/or highly reactive loads. (One can, of course, provide the amp with output impedance adjustments, an interesting technique used in the class A solid-state amps made by Sony Esprit and Sphynx, a Dutch manufacturer.) The technique of feedforward also tends to make a transistor output stage emulate the performance of triodes, and may well rep resent the optimal output topology possible with today's devices, but it still fails to achieve a perfect replication of tube characteristics, and it is very expensive to implement properly and not terribly practical--unless you count quasi-feedforward schemes like Stasis operation, or Quad's "current dumping." In any case, even with feedforward, clipping will still produce lots of high-order distortion, and there are other subtler aspects of transistor behavior which resist the linearizing effects of feedforward, class A operation, differential operation, or any other linearizing technique I know.

Transistors have more than a dozen distortion mechanisms-far more than triodes- and these include thermal de-biasing, collector/base capacitance, etc. In toto, these are productive of not only high inherent values of THD, but also complex intermodulation distortions which are not adequately represented by simple two-tone tests. Richard Bell, currently of Carillon Technologies, wrote a series of seminal papers on the subject back in the sixties, and his observations still hold good today.

Vacuum tubes are also far better isolated from electrical disturbances than are transistors. They are less disturbed by either RF or reactive loads, and can be operated in amplifying circuits without regulation, something that just isn't possible with transistors. Transistors want a rigidly controlled operating environment, and really superior solid-state amps such as the Threshold Stasis have extraordinary amounts of house keeping circuitry to keep the signal devices in linear operating modes.

I am not suggesting here that solid state amplifier design is an exercise in futility or that tube amps are the only valid choice for the music lover. I am only suggesting that the ancient technology of the vacuum tube still has something to offer and can deliver a level of performance that is very hard to emulate.

By the way, if Carver is indeed producing a preponderance of second harmonic in his t-mods, it might interest your readers if you were to explain how he achieves this result. It would certainly interest me. I have seen distortion spectra from literally scores of high-end solid-state amps, and with one exception-a Mark Levinson product-I have yet to see a solid-state amp with a tube-like spectrum. I know that Carver is using neither class A operation nor feedforward, so I am curious.

I must conclude an already overly long letter. Thank you for producing a lively publication and for discussing technical issues generally not covered elsewhere in the consumer press.

Very sincerely, Daniel Sweeney

Burbank, CA

Yes, as a letter it's overly long, but as a mini-tutorial on pro-tube philosophy it's about the right length, and I think our readers will appreciate it. Although you have obviously been recruited by the vacuum tube lobby (not necessarily commercially, just ideologically), your arguments appear to me to range from at least plausible to basically valid. On a few points I and my associates part company with you totally, as future reviews in this journal will undoubtedly evidence. The biggest hole I can punch in your exegesis is that you carefully avoid mentioning the heat generated by tubes, their far from unlimited life span, and their changing performance characteristics as they age. A tube amplifier is not an install-it-and-forget-it type of audio component, whereas a properly designed solid state amplifier is-and to me that overrides all other considerations. I'm willing to con cede that a superior solid-state amp will possibly be more complex than an equally good tube amp, from which it follows that a semipro or dilettante designer/constructor will find the tube approach more congenial.

I think you make too much of the second-harmonic issue. The Carver "Silver Seven" doesn't have such a heavily second harmonic-dominated signature, or any other peculiarity in its distortion spectrum, that there should be any problem copying its transfer function into a solid-state amplifier. Years ago, Bob Carver sent me at my request a memorandum detailing the successive steps in his t-mod procedure.

There are far too many steps, and too many details within each step, to repeat them here. Maybe one day I can prevail on him to write an article. The thing to remember-and what many audiophiles somehow fail to understand-is that you can't t-mod a sow's ear to duplicate a silk purse; in other words, the amplifier being modified has to be potentially as good as, or better than, the amplifier being copied. The basically sound circuit topology and high volt age/current capability of Bob's amplifiers give him a lot of latitude.

-Ed.

The Audio Critic:

I am extremely pleased with the back issues of your publication I received recently. They are well written and cover the finest equipment with an absolute mini mum of filler and nonsense.

Your assessments regarding the relative effect of amplifiers, CD players, loud speakers, interconnects, room and software on sound quality are a breath of fresh air and reason after reading some of the other high-end publications. The others seem to be promoting a mysticism designed to appeal to those with a fear of technology. I am afraid this is a very expensive cult.

I hope to see The Audio Critic grow and prosper, but please do not become glossy and flashy like the others.

Please find my check and subscription form enclosed.

Rod Hickerson Portland, OR

As of the last couple of years, the polarization along the reason/mysticism axis is even worse than you think. I come from an era when audiophiles believed what the professionals told them. Today their heads are filled with garbage fed to them by self appointed pundits with no credentials, who tell them to distrust the professionals. The witch doctors are elbowing aside the real doctors. Unless a strong countertrend emerges, I fear for the future of audio. This publication alone can't hold the line.

No, we won't become another slick magazine, but we must run color ads on coated stock. It's a matter of survival in a highly competitive situation.

-Ed.

The Audio Critic:

Dear Peter, Thank you for printing my letter in Issue No. 14 of The Audio Critic.

If I may comment on your response to my letter: The point of my letter is and was to get the word out to audiophiles who sub scribe to your magazine that all amplifiers do not sound the same! I carry that message to anyone who is interested in getting the best out of his system. I assume that the majority of your readers have that as a goal. I have read every issue of your magazine (journal?) since its inception. I continually get the feeling that your readers are being misled into thinking that all amplifiers sound the same. As a matter of fact, I think that anyone who has been exposed to the ABX debate could be misled. Let me say now that I have no problem with the ABX per se. I do not have any use for double-blind testing. I know that I am intellectually honest and have no motive to use some clue (cue) other than the merit of the component to identify it. I do, however, use blind testing whenever practicable. (Yes, I can guess what component is playing by identifying external cues, but I am honest enough to admit it.) After reading the roundtable discussion in Issue No. 13, it was clear to me that some individuals could get the impression that all amplifiers sound the same. As a consequence, they could purchase any amplifier they wanted based on factors other than sound quality. Consequently most audiophiles would tend to buy the cheapest amplifier within the appropriate range of specifications, or the one that had the most desirable bells and whistles. This is exactly what a large majority of amplifier manufacturers would want. Then they could concentrate on marketing, distribution and advertising, the things they do best and the tactics that lead to the most consistently high sales figures. I speak with firsthand knowledge on this point. You see, I once believed that all amplifiers were the same, a notion that was reinforced by your magazine, among others. For example, I was talking to a Carver representative a month ago, who told me that all amplifiers sound the same and he could prove it using the ABX comparator. Your magazine's endorsement of ABX double-blind testing, coupled with your claim that any amplifier working within certain parameters sounds the same, perpetuates that misconception.

Your response to my letter did little to clear that up. The fact remains that the real world audiophile (or the non-audiophile consumer) cannot make the Radio Shack amplifier sound like the Boulder 500 under any real-world conditions. Yet there are many audiophiles who will read your magazine and think that all amplifiers sound the same. Thus they will be easy prey to their desire to save money and buy the cheaper amp. Moreover, they will be tricked by the manufacturer or dealer who would rather sell a lot of cheap amps for a large profit than a few expensive ones for a small profit. The ABX comparison is an intellectual exercise with no real-world application. If the Silver Seven-t sounds exactly like the Silver Seven, then the Silver Seven is a consumer and intellectual fraud. I do not know if you were aware of it when Issue No. 14 went to press, but the Silver Seven is currently being sold as a real-world product through Lyric Hi-Fi (see Bob's inter view in the February 1990 Stereophile) at the rate of about ten per month.

Having said that, let me respond to your criticism of my letter point by point.

You state that my use of the terms "frankly gorgeous" versus "splitting head ache" hardly constitutes expert testimony.

Excuse me! You are the expert! That is what I pay you for! I am just a humble audiophile depending on you for advice. If I sound like an amateur, it is because I am.

Try this. Hard, brittle, dry high frequencies and overall dry sound versus a euphonic, lush sound. More learned audiophiles at tribute this to different orders of harmonic distortions in tube amps than in transistor amps. But then you knew that, didn't you, Peter? (Incidentally, in Issue No. 14, an ex pert like yourself describes the sound of various components using terms that I would not consider expert terminology-I assume you meant terminology instead of testimony--e.g., page 13, paragraph 2, "...The square-pulse response of the Platinum II is gorgeous..."; page 13, paragraph 3, "...Platinum II's sounded sweet, smooth, open and uncolored..."; page 15, paragraph 2, "...snappy or open..."; page 16, paragraph 7, "...too many flavors..."; page 55, paragraph 2, "...sweeter...") Peter, those double standards certainly are convenient, aren't they? As I have already said, I have nothing against the ABX comparator per se. I prefer single-blind testing of the unaltered components, since that is what the real-world audiophile takes home. "Today there exists no halfway respectable opponent of ABX testing who attacks the box itself." I think I can guess who it is you are attacking. I guess you have your own definition of respectable. My definition of respectable is a manufacturer of musical components that represent good value, and the reviewers and dealers who lead me to it. I assure you there are plenty who question not only the ABX box but the motives of those who endorse it. While we are on the subject, I wonder why no one talks about the fact that A/B testing has no real scientific value. The only question is, does the system as a whole do an acceptable job of recreating the illusion of live music at a price you can afford. A/B testing usually is just a gimmick. Do I purchase component A because it comes close to the real thing or because it is better than B? More in line with our discussion here is that the ABX really measures sonic memory. Can you remember what you just heard well enough to match what is now being played and then compare it to something you are now listening to? I knew you would refuse my offer be cause amplifiers do sound different, and you know it. You proved it with your audio dollars. The fact is that, even assuming arguendo that you could get the Radio Shack amp to sound like the Boulder, the conditions that you were able to do it under would have no real-world application. You are absolutely right, Peter, I did know that you needed an extremely high-quality amp for the lab and, more importantly, for your listening pleasure. (Although the Boulder would not have been my choice.) What do I need in my home to create the illusion of live music? Is your need any greater than mine, or for that matter than that of the thousands of other audiophiles who desperately seek to create the illusion of live mu sic in the home? I think I see it now, Peter: you are not a hypocrite, you are a snob! What you are really saying is that all things being equal (and you concede that in the amplifier world they never are), you can make two amps sound the same. For that matter, I could compete in the ring with Mike Tyson if you equalized (pun intend ed) our strength, size, physical skills, knowledge of and experience in boxing, and desire to win. But it just does not hap pen that way in the real world.

No, you did not say the Radio Shack amp will sound like the Boulder under all conditions, but you implied it. I'm glad you cleared that up. The only way to get the sound of the Boulder 500 is to buy the Boulder 500. That is why you purchased the Boulder instead of any of the cheaper amps available to you, including the Carvers!

[ intended this letter to be provocative and to spark debate. Sending it to Stereophile and The Absolute Sound increased the chances that it would be printed. Indeed, it was printed in The Absolute Sound. In answer to your question, I often comment on pending legislation that affects my clients and, yes, I do send copies to all involved.

Thank you for considering my point of view.

Reginald G. Addison

Attorney at Law Washington, DC

CC: The Absolute Sound Stereophile Your point of view? You have no point of view, except for a knee-jerk aversion to moderately priced audio equipment and an obvious fondness for the sound of you own voice as you keep repeating yourself. I flatly refuse to defend what 1 "implied" (in your opinion!), or what "some individuals could get the impression" of, or whatever gave you "the feeling" you elaborate on.

The defense would, in any event, consist of a literal quotation of what I wrote, and that you already have in your possession. I said it all then and there. The Audio Critic is written for attentive, comprehending readers, not for those in need of a remedial reading class. What I print is what I mean, exactly as you read it, nothing more and nothing less. Your simplistic and subjectively distorted restatement of what I wrote, or what the seminar participants said, is not something I should have to deal with.

That said, let me comment on some of your rhetorical maneuvers, counselor. You say you are intellectually honest, but I find certain indications to the contrary in the above letter. For example, you say you have read every issue of The Audio Critic since its inception, but then why are you unaware that my present position on electronic sound-alikes is quite recent, not even fully evident in Issue No. 10? As for your out-of-context quotations of my descriptive adjectives and phrases, maybe a jury of trade-school dropouts from the District of Columbia would fall for such a shabby courtroom trick, but not our readers. Of course I use those basic and very useful words-in conjunction with other words presenting objectively verifiable data. compare: "Please describe the young woman you saw walking away from the scene of the crime." "Quite frankly, she was gorgeous." As against: "She was a Caucasian brunette, about 24, approximately 5 foot 7, very shapely with long legs, wearing a tight blue dress and little makeup. Quite frankly, she was gorgeous." Yes, counselor, I meant and still mean testimony, credible testimony. The terminology can vary, depending on what is being said.

You also seem to be innocent of the commercial facts of life in audio. There is more money, for the manufacturer and for the dealer, in selling a $6000 amplifier than there is in ten 3600 amplifiers. The entire cost/wholesale/retail structure is far more stringent in the lower price ranges than at the high end, where the figures can be arbitrarily set at whatever level the traffic will bear. As for the Silver Seven "fraud," Bob Carver tells the consumer right up front that the "t-mod" sounds exactly the same, after which the high-end tube freak is on his own, free to part with 817,500 or not. Does that constitute fraud? Should there be a Surgeon General's warning on the chassis to the effect that this product is dangerous to your pocketbook and offers no benefits beyond what is obtainable for $2000? The Silver Seven was originally intended to be a tongue-in-cheek engineering exercise; it was Harry Pearson and Mike Kay who took it seriously and made it into a business.

Your cavalier dismissal of double-blind testing has me in a quandary. The world's leading authorities in psychophysics consider it to be absolutely essential in order to obtain valid results, not only in audio but in dozens of other areas of investigation; the world's leading medical researchers insist on it for testing new drugs; but Reginald the Lawyer says it has no value.

Now I don't know whom to believe.

All this is more than I really intended to write in response to an inconsequential, hassling letter. Please do not reply again.

Be happy with your two soapbox opportunities so far.

-Ed.

The Audio Critic:

Your long efforts to define the perfect loudspeaker give me the feeling that you're trying to prolong the suspense. Let me suggest a concept. A loudspeaker should have the same frequency response in all directions. An equivalent statement is that a loudspeaker should have the same directional pattern at all frequencies. This characteristic is called constant directivity.

As described in Benchmark Papers in Acoustics, the loudspeaker was still a re cent invention when the best minds in the audio business were called upon to design systems for movie theaters. Obviously, flat frequency response was required over the band to be covered. The designers quickly realized that flat frequency response with out constant directivity was inadequate, be cause there would then be some direction in which the frequency response would not be flat. Floyd Toole rediscovered this just a few years ago. The microphone people have always known that flat frequency response in all directions was the ideal characteristic. Having lots of tricks available, they've been able to come pretty close for a variety of patterns.

For two reasons, it is not natural for a conventional loudspeaker to give flat frequency response with constant directivity.

First, a conventional loudspeaker becomes less efficient at high frequencies where the radiation resistance stops rising, so that equalization is required to maintain constant power output. Second, the beam width tends to increase at low frequencies where the diaphragm becomes small relative to the wavelength, so that a horn is typically required to restrict the angular coverage.

During the thirties, for reasons of cost, most designers of loudspeakers for the home abandoned correct design forever.

The few people still trying to design constant-directivity loudspeakers have been getting good results for only about twenty years. Most horn systems are still bad enough to lead critical listeners to the conclusion that the concept of constant directivity is wrong. The concept that's wrong, however, is the belief that it's enough for a loudspeaker to be flat on axis.

Sincerely, William J. Roberts

Toledo, OH

What you say is absolutely correct, but what you forget is that a recording that was balanced by the producer over conventional loudspeakers will in most cases sound far too bright when played through constant-directivity speakers. Unless some body says, "One, two, three, go!" and the entire audio community changes to constant-directivity speakers at the same time, this problem will remain with us. Further more, not all constant-directivity loud speakers sound the same, either. Yeah, it's a lot easier to design amplifiers.

-Ed.

The Audio Critic:

Although your publication continues at a generally high level of quality, your snide remarks about other publications is inappropriate and insulting to your readers.

Just because The Absolute Sound has re sorted to such a style in the past doesn't mean you should emulate it; in fact, I no longer read that magazine, in part because of that (and I'm sure I'm not alone in this).

The comment about Stereophile's re views of non-cone-type loudspeakers being suspect is wrong, for two reasons. First, the mere fact that Carver is able to modify his ribbon to make it less altitude sensitive means (to me) that this should have been a design parameter from the start; there are enough audiophiles who live at altitudes high enough to incite altitude sickness that they should not be ignored. Second, like nearly all audiophiles, Stereophile's writers prefer various non-cone speaker systems, and in general the same ones audiophiles prefer at sea level. If in fact they don't like some systems at their elevation which seem to sound better at sea level, I would not consider that speaker to be a reasonable recommendation. Imagine the audiophile who, shortly after his audition and purchase of Carver's Amazing Loudspeaker at a sea level dealer, gets it to his home in the mountains and finds himself (rather) disappointed with the sound.

Such attacks are not in keeping with your stated mission and philosophy. Continue to present your data and opinions in ways that readers can enjoy them most, and try to ignore those aspects of your competition which reflect poorly on all of us (the audiophile community-the sensible part).

Yours truly, Rob Bertrando Reno, NV

I have two, and only two, reasons for castigating another audio publication. One is that they attacked me, or The Audio Critic, first. The other is that they are spreading major disinformation on the subject of audio. Stereophile qualifies on both counts. In 1988, they tried to destroy my credibility via their "Letters" column and did not publish my perfectly civil but highly embarrassing corrective reply. Since then they have been taking potshots at me and my publication at every opportunity. Are you asking me to turn the other cheek? (The first and only persuasive advocate of that policy ended up in a situation I would find unacceptable.) As for disinformation, Stereophile is now the most influential disseminator of audio myths, fantasies, and fetishes, the chief apologist for the school of "A blows away B because my exquisite ears say so and I don't have to prove it." To me that constitutes an irresponsible journalistic butt just begging to be kicked.

When accountability becomes the rule rather than the exception within the high-end audio community, the prevailing intramural tone will surely be less confrontational.

I agree with you 100% that the Carver "Amazing Loudspeaker" should not have been released before the altitude sensitivity problem was fixed, as it is now. Bob Carver himself admits it was a serious oversight.

That, however, doesn't make Dick Olsher's amateurish and often downright silly loud speaker reviews more respectable. The man is an undisciplined seat-of-the-pants dabbler in a technology he only partially understands. Yes, a carefully designed loud speaker should work properly at all inhabit able altitudes, but no one will convince me that electroacoustic measurements made at 7000 feet above sea level are good, reliable practice. I never saw any qualifications or caveats in Stereophile's test reports.

John Atkinson's obfuscatory editorial of May 1990 on this altitude controversy is addressed elsewhere in this issue (see "Hip Boots").

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[adapted from TAC, Issue No. 15]

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Also see:

Seminar 1989: Exploring the Current Best Thinking on Audio, Part III of the Continuing Transcript

Various audio and high-fidelity magazines