Audio Critic the 25 r schematic

Look, Ma, no amplifiers! (Well, no amplifiers to buy, anyway. See the loudspeaker reviews.)

Issue No. 25

Display until arrival of

Issue No. 26.

Retail price: U.S. $7.50, Can. $8.50

In this issue:

We review a wide assortment of loudspeaker systems, including minimonitors, various full-range speakers, and powered subwoofers from extra small to large.

We continue our notorious survey of the White Hats (good guys) and Black Hats (bad guys) of audio.

Power amps, integrated amps, multichannel receivers, digital processors, CD and DVD players, FM gear, and a minimalist preamp are reviewed in depth.

The end of innocence in audiophilic matters is the aim of a down and dirty orientational think piece.

Plus our usual features, columns (we have added a new one), letters to the Editor, and more CD capsule reviews.

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Box 978: Letters to the Editor

Book & Software Reviews By the Staff of The Audio Critic

Ben Duncan • Douglas Self • Howard Ferstler • Robert Harley • ETF4.0 • RPG Room Optimizer

Capsule CD Reviews 65

Sidebar:

Object Lesson

Creeping Subjectivity

By Peter Aczel, Editor and Publisher

The Audio Cynic

By Glenn O. Strauss

Hip Boots

Wading through the Mire of Misinformation in the Audio Press 59 Synergistic Research: through a Forest, Darkly 59 Robert Harley in Fi Magazine 62 Peter van Willenswaard in Stereophile

New World Cyborgs

By Tom Nousaine

An Alphabet Soup of Electronics: AV, DVD, CD, FM, THX, AC-3, DTS (all A-OK)

By Peter Aczel, Editor and Publisher, and David A. Rich, Ph.D., Contributing Technical Editor

41 AV Surround Receiver: Denon AVR-5600 43 DVD Video Player: Denon DVD-3000 43 Digital Surround Processor/Controller: Lexicon DC-1 44 FM Tuner: Magnum Dynalab FT-101A 47 Dolby Digital AV Preamp/Tuner: Marantz AV550 47 Mono Power Amplifier: Marantz MA700 48 Dolby Digital Processor: Marantz DP870 49 Line-Level Preamplifier: Morrison ELAD 50 Outboard D/A Converter: Parasound D/AC-2000 51 5-Channel Power Amplifier: Rotel RB-985 THX 51 Compact Disc Player: Sony CDP-XA20ES 52 CD/DVD Player: Sony DVP-S7000 53 Hi-Fi VHS VCR: Sony SLV-M20HF 54 AV Surround Receiver: Sony STR-DA80ES 55 Indoor/Outdoor FM Antenna: Terk FM Pro FM-50

...and something you always looked for:

56 Service Manuals: A. G. Tannenbaum

There's Life Yet in the Two-Channel Integrated Amplifier

By David A. Rich, Ph.D., Contributing Technical Editor

35 Denon PMA-2000R 38 Onkyo Integra A-9911 36 Marantz PM-68 39 Yamaha AX-592

About Minimonitors, Subwoofers, and Full-Range Systems In Between

By Peter Aczel, Editor and Publisher

19 Bag End Infrasub-18 26 Pinnacle Classic Gold Aerogel 20 Bag End MM-8B Time-Align 26 Sunfire "True Sub Signature" 21 Hsu Research HRSW 12Va 29 Thiel SCS2 21 JosephAudio RM7si "Signature" 30 Velodyne Servo FSR-18 22 Legacy Audio "Studio" 31 Velodyne Servo HGS-10 23 Monitor Audio 700PMC 32 Waveform Mach 17 (followup) 23 NHT Model 2.5i 24 Paradigm Reference Active/20 .. .and another kind of transducer: 25 Paradigm Reference Servo-15a 33 Sennheiser HD 600

How to Be a Sophisticated Audiophile and Resist Trendy Stupidities

By Peter Aczel, Editor and Publisher

The Good Guys in the White Hats and the Bad Guys in the Black Hats: Continued

Bv Peter Aczel, Editor and Publisher

Contents

15 19

57 59

61 63 68

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Issue No. 25 Winter 1998-99 Editor and Publisher Peter Aczel

Contributing Technical Editor David Rich Contributing Editor at Large David Ranada Technical Consultant (RF) Richard Modafferi Columnist Tom Nousaine Columnist Glenn Strauss Cartoonist and Illustrator Tom Aczel Business Manager Bodil Aczel

The Audio Critic® (ISSN 0146-4701) is published quarterly for $24

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18951-5221. Second-class postage paid at Quakertown, PA. Postmaster: Send address changes to The Audio Critic, P.O. Box 978, Quakertown, PA 18951-0978.

The Audio Critic is an advisory service and technical review for consumers of sophisticated audio equipment. Any conclusion, rating, recommendation, criticism, or caveat published by The Audio Critic represents the personal findings and judgments of the Editor and the Staff, based only on the equipment available to their scrutiny and on their knowledge of the subject, and is therefore not offered to the reader as an infallible truth nor as an irreversible opinion applying to all extant and forthcoming samples of a particular product. Address all editorial correspondence to The Editor, The Audio Critic, P.O. Box 978, Quakertown, PA 18951-0978.

Contents of this issue copyright © 1998 by Critic Publications, Inc. All rights reserved under international and Pan-American copyright conventions. Reproduction in whole or in part is prohibited without the prior written permission of the Publisher. Paraphrasing of product reviews for advertising or commercial purposes is also prohibited without prior written permission. The Audio Critic will use all available means to prevent or prosecute any such unauthorized use of its material or its name.

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2 THE AUDIO CRITIC

From the Editor/Publisher:

Our efforts to become part of a larger organization (see this same space in the last issue) have so far elicited some interest in the publishing world without producing an acceptable partnership. Thus your graying Editor remains a one-man band—in the laboratory, at the computer, in the writing/editing/publishing loop—putting out a magazine single-handed, from ground zero to camera-ready mechanicals for the printer. If 1 stopped having a life and devoted every waking minute to the job, I could

probably cut in half the interval between

issues. That interval, as this issue proves, tends to be so long that even half of it is unacceptable, leading to the inescapable conclusion that getting plugged into a larger publishing operation is the only sensible

plan. Rest assured, it will happen, maybe

soon, maybe later. Meanwhile you hold in

your hand two issues' worth—counting the

number of test reports, other reviews, and

features—for the price of one.

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Box 978

Letters to the Editor

Your letter has a good chance to get published here if it is a relevant commentary on audio issues or the contents of our journal. Please send only typewritten or word-processed text; our scanner software does not recognize hen scratches. Letters 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 18951-0978.

We lead off with an object lesson about the perception of consumer audio by the general (i.e., nontechnical) press. The following exchange of letters between

your Editor and Forbes magazine took place

a few months after the publication of Issue No. 24. The letters are self-explanatory.

Mr. James W. Michaels, Editor

Forbes

New York, NY

Re: "Going vinyl" by Stewart Pinkerton, under Living, Forbes, July 7,

1997. Dear Mr. Michaels:

As a well-wisher of Forbes, I feel compelled to point out to you the utter lack of science, professionalism, and accountability in the above article. It seems you have been snookered by Mr. Pinkerton and the agenda-driven tweako/ weirdo audio cultists he hangs out with. He obviously does not know how to network with authorities possessing serious technical credentials.

"...Records sound better than CDs because they're direct analog copies of a musical event, rather than digitized reconstructions." "...A high-quality photograph looks much better than a digital image. The detail is sharper, the color richer." This is a scientific illiterate talking. The Nyquist-Shannon sampling the-

orem and the principles of quantization provide unequivocal assurance that with

44.1 kHz sampling and 65,536-step quantization as used in CDs no "detail" in the audio spectrum and the audio dynamic range is lost—not an iota, not a scintilla. By any criterion of audio fidelity— frequency response, dynamic range, distortion, signal-to-noise ratio, channel separation, etc.—the CD medium is devastatingly superior to vinyl. Today's LP microindustry is based on nostalgia and the utilization of leftover production facilities, not technical advantages. Mr. Pinkerton's so-called comparative test was a typical salesman-coached exercise in undisciplined subjective expertizing, without any scientific controls (such as level matching, double-blind conditions, etc.).

What I see as the root cause of your editorial problem here is your Rolodex. You and your writers do not appear to have the names and telephone numbers of genuine audio experts. To use a simple analogy, instead of asking the Mayo Clinic about medical questions you have been asking your local health food store. For solid information about audio, you need to be in touch with the Audio Engineering Society (AES), with the Institute of Electrical and Electronics Engineers (IEEE), with tenured profes-

sors of electrical engineering, acoustics, physics, and applied mathematics at leading universities, with the top engineering executives of major manufacturers in the field, and so forth. Not with retail stores trying to sell you the stuff, for heaven's sake, or with untutored hobbyists rationalizing their purchases. You cannot imagine the utter contempt and jeering ridicule elicited by Mr. Pinkerton's kind of unscientific journalism from the top professionals and academics I am talking about.

If you are serious about upgrading Forbes's capabilities in this area, I shall be glad to help you assemble a better Rolodex. I have all the best names and numbers, and want no compensation other than improved hi-fi reporting in Forbes. Meanwhile I am enclosing a couple of clippings from my publication that have some relevance to this matter.

Sincerely, Peter Aczel Editor and Publisher Life Member of the AES

Dear Mr. Aczel:

The typical Forbes reader doesn't have a doctorate in acoustics or electrical engineering. But, many of them do spend a good deal of money on hobbies such as audio. Thus we're interested in giving

ISSUE NO. 25 • WINTER 1998-99

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them an insight into the available choices in the market. There's just as much hype

coming from the CD enthusiasts as there

is from the vinyl advocates. I'll pass your

comments along to Mr. Pinkerton.

Thanks for taking the time to write.

Sincerely,

Jim Michaels

Editor

Forbes

I couldn't believe my eyes when I

first read the above reply. Apparently,

correct information is strictly for Ph.D.s, not for "the typical Forbes reader." But wait! It turns out that they did listen to me, even if they won't admit it directly. In their December 28, 1998 issue there is a short article by Robert La Franco, titled

"Selling sizzle with sizzle." It is about Noel Lee and the Monster Cable success story. The focus is on the business aspects of the audio cable industry, but La Franco also points out that high-priced stereo cable "is a product where most of the value is in the mind of the buyer" and that heavy-gauge lamp cord "affords nearly as much fidelity." Isn't that amazing? It's definitely a first in a business

magazine. Am I being presumptuous to take a little credit for Forbes's turnabout?

—Ed.

The Audio Critic:

I was most pleased to see that you put me on the side of the White Hats. I always tried to be so. I also appreciate

your kind words about me in Issue No. 24.

Your list of important things in

audio on page 9 [of No. 24] is right on the mark. I have supported these priorities for many years. You state them boldly and succinctly.

After many years I have retired from

professorship and from writing or even commenting on audio matters. I still do some consulting in acoustics and digital signal processing. But, my main pastimes are now gardening and astronomy. They are both slow, gracious and relaxing activities most suited to retirement.

While I no longer consider the

"tweakos" worth arguing with or worth trying to educate, I wish you well in your continuing battle on the side of truth, right and justice.

Sincerely, (signed) Dick R. A. Greiner Emeritus Professor of Electrical and Computer Engineering

Dick Greiner is one of the towering authorities whose name should be on Forbes's Rolodex (see above). They would find him kind, highly approachable, and prompt to respond, but of course they are unlikely to consult him. That the editorial stance of this journal has his complete approval is one of the things that make me sleep better at night than Larry Archibald and John Atkinson (if indeed there is any "truth, right and

justice" in this world). Thank you, Dick, for having been a beacon all these years

in the murky sea of audio.

—Ed.

The Audio Critic:

Please permit me a little 3-way link-

age. I would like to respond to Dan Sweeney's excellent article on multichannel sound, focusing on speaker directivity and "Can One System Do Both?" etc., in Issue No. 24, and combine those thoughts with some generated from

Floyd E. Toole's also excellent article in Audio magazine (May & June 1997), especially since Floyd Toole was mentioned in Sweeney's article. It is nigh impossible to treat this subject matter in one letter. At the same time, I hope to

shed some light on your query in the review of the Waveform Mach 17, about the missing connection to "the variability of response in the vertical plane" (Issue No. 24, p. 34).

For the most part, speaker designers assume that the listener is seated. This means that the listener will obtain the majority of the combined acoustic output in the horizontal hemisphere from a neutral room. Even when the dispersion model chosen is the point source, stacking bass, midrange and treble drivers vertically on a baffle will result in fairly severe broadband nonlinearity generated in the vertical plane at ever increasing wide angles. These are taken fully into account when the total radiated sound power is compiled. One will then also be able to deduce the directivity index, which now appears to be the current darling measurement for the video crowd.

The listening window, which is a computer-generated curve at the NRC, contains the 15° up and down measurements, along with the 0°, 15° L & R. Measuring up and down this amount will help account for what a standing person will experience at a reasonable distance of about 10 feet from a stereo pair. If a listener insists on standing on a ladder or

lying on the floor at this same distance, the audible response from the same product may not be quite as memorable. Waveform does include this measurement, along with 17 separate others, in our owner's manual. What is noteworthy here is that the shape and level of the window matches very closely the on-axis curve, something we have never witnessed before.

With respect to multichannel sound, what needs emphasizing is that nowhere in either article, by either author, is there

a persuasive defense enunciated for speakers having differing directivity characteristics for film sound and for the sound of music. Sound is sound. To quote Toole: "In principle, there should be no reason to differentiate between them. Good design is good design." (Audio, May 1997, p. 137.) It is not my intention to enter into an audio vs. video debate; the marketplace is already doing that, and to audio's detriment. I also have no theo-

retical quarrel with a speaker that has constant directivity. It is a desirable attribute, but only after the main horizontal curves have been made flat. The sacrifices made are too great in attaining it, although it now may be possible to have both within the same product. Where is the diffraction model in a square-edged cabinet with a horn driver? Where is the diffraction model in a dual-element, dualuse speaker? Where is the acoustical interference model for dispersion in designs with multiple tweeters or midranges, for that matter? And where are the comparative listening tests that show that a listener would prefer this compromise to any other? Constant directivity is achieved, in my view, at the expense of flat extended frequency response in the

three-dimensional sound field, whether one employs horns or multiple drive elements.

Speakers that are designed with a smooth and extended dispersion plot are not done so with the intention to provide ambience by bouncing off the room boundaries, as Daniel Sweeney suggests (Issue No. 24, p.71). That this does occur is usually a direct result of a too-live listening room. Controlled dispersion is executed to emulate the point source concept as defined by frequency, not phase. It is up to the user to provide a suitable room acoustic with a predominantly direct sound characteristic, which will happen as a result of low reverberant decay (0.3 s to 0.4 s) as specified (or

4 THE AUDIO CRITIC

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buried?) in the literature, but not emphasized nearly enough by those who presented and argued for it in the first place.

Since home theater systems are only in about 10% of North American homes, interesting things begin to appear when the demographics of these owners are examined more closely. The early adopters have more discretionary funds to dispose of. Their homes are typically larger and therefore the rooms are larger too. Not so good, as large rooms inherently have longer reverberant times, which lead to louder echoes. The room may be a showpiece and may have only an area rug on a tiled surface or hardwood floor, as opposed to full broadloom. Not so good either, as the potential for flutter echo between the exposed floor and the ceiling is awaiting a trigger mechanism to explode. The owner may have a ravine lot with no neighbours to the rear, so the need to have privacy drapes on expansive glassed walls is reduced or eliminated. More reflective surfaces (and big ones too), not so good again, almost redundantly so. The main reason for controlling the vertical dispersion in THX speakers, as well as with some of the new constant-directivity models, is that owners of home theatre systems and installers have not come to grips with the needed room acoustic, which would require lowering the room sound and raising the speaker sound. Not easy!

There is also an absolute dearth of discussion regarding the correct use of the centre channel. Virtually all on-screen dialogue in films is summed to this speaker, so that actors sound as if they were piggybacked on top of each other in the same wretched fashion that multitrack music recordings stack vocalists and performers vertically in the centre between the L and R channels. The centre channel is not a universal cure-all for listeners sitting off the central axis. Most importantly in music, but no less so in good dramatic film dialogue, there will have to be more care used in creating phantom images between the L & C and the R & C. Here again, level is more important than phase.

One last point about having five identical channels. If, as Floyd Toole suggests, the side channels shouldn't be exactly like the front channels in timbre because of the outer shape of the ear, then it should be up to the encoding within the system software setup to re-equalize the

timbral balance of those side channels for where they are positioned on the wall, by height and by distance, either fore or aft of a centrally located listener with head forward.

The really big picture is the one that contains all of the product measurements, all of the room measurements, and all of the psychoacoustic optimizations. There is a level of sophistication needed here that has never been attempted before. Those who do it first and do it correctly will reap the rewards. Then the only difference that remains will be the recording as art form. Is there the will?

Sincerely, John Ötvös President Waveform

The trouble with all theoretical speaker-design priorities, even if intelligently and knowledgeably argued as in

your letter, is that "the proof of the pudding is in the eating," i.e., you have to point to an already existing design that incorporates those priorities before we can all be thoroughly convinced. Loudspeakers are not like amplifiers. In speakers there is no such thing as a 100% hardware implementation of a paper design. "Between the potency/And the existence/...Falls the Shadow" (T. S. Eliot). Sometimes a conceptually flawed design sounds better than a brilliant one as a result of better execution.

Since the Waveform Mach 17 is,

overall, the most successful loudspeaker design known to me, I take your priorities very seriously and await eagerly the grand synthesis they wishfully and wist-

fully point to.

—Ed.

The Audio Critic:

I think that it would show that you

had manners befitting a serious journal if you didn't use such strong language to describe those lyin', cheatin', dirty, rotten sons o' bitches/bastards!

David Franklin Edgartown, MA

Who uses strong language ? Not this

freakin 'journal! (But then all criticism is

perceived as strong language by the criticized. "Don't speak of rope in a hanged man's house," says an old Hungarian proverb, but that doesn't mean rope is a dirty word.)

—Ed.

The Audio Critic:

...I want to reassert forcefully: thank you for The Audio Critic. It has brought the clear light of day into an area of consumer life that I had been bumping around in clumsily for all too long. I do not think integrity and clearly developed reasoning and crisp, straightforward prose are anywhere in our culture ready to hand; it is precisely these virtues I find on every page of your Issue No. 24, which is the first issue of your journal I've met; and I cannot be quick enough in subscribing and including amounts for

...back issues...Nos. 16-23.

...Believe me, I will not complain about irregular publication schedules. I tell my students the same warning about when to expect back papers they hand in: if I am to do a good job commenting, they must wait until I am ready. Besides, the rich substance of what I read in this single issue provides me with plenty to reflect on.

As our literature studies try to include more cultural contexts, I find myself always making students alert to the hype of consumerism; and your journal performs that great service in an area where I hear almost no one else speaking.

Thank you again very much.

Sincerely, Roger Kaye Department of English California State University Chico, CA

Isn't it remarkable that university

people endorse and support us so much more consistently than the untutored audio-salon dweebs and magazine-rack moochers? Is there a sociocultural conclusion to be drawn here?

—Ed.

The Audio Critic:

You sure have put some of the fun and sanity back into audio. Your "Good

Guys/Bad Guys" article in Issue No. 24

was great, and long overdue. However, one question begs to be asked: Why is it so easy for you to forgive Bob Carver's advertisements? When Bob's ad declares

that his Sunfire amp has the soul of a 9-

watt triode, he may simply be trying to double his revenue, but he simultaneously glorifies and legitimizes the whole high-end mystical megabucks rip-off routine that your publication has so often denounced. Since most of us longtime audio enthusiasts respect Carver's techni-

ISSUE NO. 25 • WINTER 1998-99

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cal achievements, his ads serve only to confuse us. If Bob is intentionally misleading the audio public in order to increase his income, doesn't that qualify him for "bad guy" status right up there with Dennis Had or Conrad and Johnson?

Terence R. Simmons New Hope, PA

Bob Carver is a "Good Guy in a

White Hat" because he gives you a wellengineered—sometimes brilliantly engineered—product at a fair price. Dennis Had and Conrad-Johnson are "Bad Guys in Black Hats" because they give you dumb-ass tweako engineering at an unconscionably inflated price.

That does not mean Bob Carver's advertising is as good and credible as his Sunfire product. As a former advertising

professional I have told him more than

once that he should not write his own

ads, but he just can't live with anyone else's words—or taste. I happen to know that he secretly congratulates himself for being a hard-nosed marketeer who understands that consumers and dealers must be told what they want to hear, not necessarily the facts. In other words, he is willing to let you buy the right product (his) for the wrong reasons. Not because he is money-hungry—his entire biography would be totally different if he were— but because he thinks that's the way smart marketeers operate. Sometimes he even lapses into borderline tweakspeak

just to gain the confidence of the tweako

element, although I know for a fact he shares none of their beliefs.

A famous dictum of Bill Bernbach, one of the smartest admen of all time, is that good advertising makes a bad product fail faster. The logic of that is unassailable, but I certainly do not believe the reverse is true—that Bob's bad advertising is making his good product succeed

faster—although it probably makes little

difference one way or the other. At this

point he is a legend, and legends are selfperpetuating. He could quite possibly

stop advertising altogether and hardly

feel the effect. The bottom line from the

Good Guy/Bad Guy perspective is that it would be good for audio if Dennis Had and Conrad-Johnson went away but bad

for audio, very bad, if Bob Carver went

away. We need him, warts and all.

—Ed.

What follows is a conflation of three

letters over an eight-month period from

Howard W. Ferstler, author of consumeroriented books on audio and contributor to The Sensible Sound. Howard often reminds me of Gertrude Stein's famous quip about Ezra Pound: "a village explainer, excellent if you are a village, but if you are not, not." That was of course patently unfair to Ezra Pound, who was a great poet albeit a nut case, and is also somewhat unfair to Howard, who always fights on the side of scientific rationality in this delirious world of high-

end audio. Still, he does tend to be a bit self-important and condescending (which may be just a professional mannerism, as he comes from the university world),

whereas I would much rather not be

treated like a village (pace Hillary). I have therefore inserted a few brief interruptions into his text, in addition to the longer reply at the end.

—Ed.

The Audio Critic:

.. .You probably get compliments all the time, but I still thought I'd tell you what a great item Issue No. 24 was. Everything was terrific: Nousaine's contribution, Sweeney's contribution, Rich's contributions—even your [viz., the Editor's] contributions. You do a hell of a

job with a three- or four-man writing

staff. [It's really a one-man writing staff

with occasional outside contributors who need to be edited.—Ed.] Also glad to see

you tested some cheaper gear and pretty much substantiated what I have said about it—some of it, at least—in two different books on audio hardware: the stuff can work pretty darn good, and impoverished audiophiles can at least have decent sound without feeling ashamed of their electronic hardware or having to hock the silver.

One quibble. On page 25, you state that "a tall planar or line-source speaker puts the listener in the farfield even when he sits fairly close." Well, Peter, that is

just not the case. With tall line sources, it

is nearly impossible to get into the farfield at nearly any frequency when situated in nearly any home listening room—not at bass frequencies, anyway.

The behavior of line sources has been

studied to death, but I suggest you read Stanley Lipshitz's paper, "The Acoustic Radiation of Line Sources of Finite Length," presented at the 81st Convention of the AES, November 1986, and hopefully still available as Preprint 2417 (D-4). Stan pretty much came down on

the whole concept of tall line sources,

mainly because when sitting close to them the top and bottom parts of the line will be radically out of phase with the center at a multitude of frequencies. Roy Allison also dealt with the subject in the BAS Speaker (August/September 1984), and Roy and Stan did a give and take on the subject in the December 1984/January 1985 and February/March 1985 issues. Short, controlled-length lines (as with some THX speakers) can work OK, but really long lines can cause problems unless they are placed very carefully and the listener sits just so.

Another quibble. In your review of the Sunfire subwoofer (see page 33), you note that "the Sunfire has the inherent ability to take advantage of the quasihorn effect of the corner; the bigger subwoofers much less so." Well, it may seem that way, but at the distances involved (a

typical 18-inch sub might have its driver centered a foot from two boundaries and two feet from the third) and the frequencies involved (usually below 100 Hz) the drivers of the Sunfire and the bigger unit are both acoustically close to those reflecting surfaces. Indeed, at very low frequencies corner reinforcement is probably no better than midwall reinforcement in normal-sized rooms, as long as you do not take the inherent structural stiffness advantage of the corner into account.

Finally, no doubt like a lot of your readers, I am still not sure of what a "wave launch" is and how it impacts the subjective performance of decent, widedispersion speaker systems operating in normally reverberant listening rooms— with those speakers placed anywhere other than close to and aimed directly at the listener.

• • •

...On page 71 [of Issue No. 24], in his fine essay on multichannel music formats, Dan Sweeney notes that the parameters for THX speaker performance mandate that "wide-dispersion designs for the front speakers are to be positively avoided in a multichannel playback system." He goes on to note that "THX speakers sound identifiably different than the quasi-point-source radiators that comprise the bulk of the well-regarded audiophile music speakers." Finally, on page 72, he pretty much comes out and says that video-oriented speakers cannot match the integrity of speakers designed for two-channel audio use, and that the

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build quality of video speakers often does not match that of audiophile systems.

Well, I should point out that in terms of dispersion the only major difference between THX-certified speakers and many audiophile models involves the vertical angle. As far as horizontal dispersion is concerned, typical THX models are a match for many so-called audiophile models, particularly those that employ rather large drivers for the midrange. Dan should have noted that limited vertical dispersion will attenuate ceiling and floor reflections that will possibly muddy the clarity of both video and audio-only playback material. There is nothing inherently wrong with limiting vertical dispersion a bit, although, admittedly, the short line-source configuration can cause lobing anomalies that might be a problem if the listener is off the vertical axis somewhat. However, those lobing anomalies are slight, compared to the ones found in typical, high-end, paneltype speakers.

Being "identifiably different" (page

71, again) does not by necessity make

THX speakers sound less accurate than

so-called point-source audiophile speak-

ers. Indeed, the differences noted may be

the result of improved fidelity. In addition, build quality is something that a manufacturer can adjust with any kind of speaker—THX-certified or audiophile. Lots of so-called high-end speakers with very expensive drivers, massively built cabinets, and exotic crossovers, as you most certainly realize, do not sound all that hot.

Perhaps the best compromise in a

speaker for both audio-only and home-

theater use would be a design like the discontinued Allison IC-20. That system had

two vertical midrange-tweeter-tweeter-

midrange panels angled 45° on either side of the forward axis, and the result combined a THX-style vertical radiation pattern with an extremely wide horizontal

radiation pattern. Of course, mating a center speaker to that stereo pair would require building some kind of customized

model—with Allison components— which I am happy to say I have done. [So

yours is the biggest, right?—Ed.]

• • •

...In assorted editorial commentaries over the years, The Audio Critic has noted with varying degrees of dismay and passion how so many of those involved with audio journalism appear more interested in tweakish speculation than in sci-

entific analysis or even in music. Those commentaries have pretty much been on the mark, in terms of what is going on, but not always exactly at dead center, in terms of the motivations involved or the consequences of those motivations. [Your

commentaries, on the other hand, are "at dead center," right?—Ed.]

It is interesting that audio, which deals with something so esoteric as the subjective perception of music, has divided into two, for the most part polarized, camps. On the one hand, we have "technophiles," who thrive on brass-tacks analyses and see the discipline as simply an offshoot of science and technology in general. Many audio technophiles are as much at home with physics, computer science, or rocket science as audio, and their audio magazines of choice are probably the JAES and JASA, and, well, TAC.

[Isn't that "well" a little condescending? See what I mean?—Ed.] Indeed, comput-

er science has probably drained off a number of talented individuals who would otherwise be heavily immersed in audio technology, and because of this defection of talent our hobby is the worse

for wear. At the other extreme, we have a coterie of mystics who often appear to encompass a much wider audience, one

that thrives on fantasy and demands a

certain amount of obscurity in their audio

lives, and I imagine their day-to-day lives as well. That the latter group is willing to spend a lot more money on hardware than the former has certainly not gone unnoticed in journalistic circles. Both groups profess an interest in music, although members of both camps are often more interested in hardware than qualities of performance.

I know of no other "high-tech"

hobby that has participants of such wide-

ly varying temperaments and attitudes. It is truly a peculiar situation.

In any case, you previously seem to have divided the subjectivist writers who appeal to this surprisingly large, mysticoriented group into two sections: The Con Men (those who know the truth but

keep it hidden for monetary or power-trip

reasons) and The Dupes (those who really believe what they say). It is clear that you consider the former category to be the larger one, with only a handful real crazies occupying the duped-journalist category.

However, it is possible that there is more to the world of subjective-audio

journalism than what is indicated by this

kind of breakdown, and I think that you and a number of other rationalist critics

(including many individuals who have written letters to your magazine about the problem) may be missing an important point concerning what a lot of subjectivist writers, and their editors and pub-

lishers, are doing (and are aware that they are doing) when they do seat-of-the-pants equipment evaluations and propose arcane theories of high-end hardware performance.

Indeed, I think we can actually go so far as to postulate a third subjective-journalist category, and it is just likely that it is a grouping that encompasses a sizable number of those who write about the sub-

ject of high fidelity, including both The

Con Men and The Dupes, whether they write for mainstream or fringe journals:

The Entertainers.

You see, a great many audio-journalistic entertainers are not being paid to impart "knowledge" at all (be it the brasstacks oriented stuff the technophiles crave, or even subjectivist-oriented fluff), because a surprising number of readers are simply not interested in technical information—even subjectivist, pseudoscientific, seat-of-the-pants technical information. The fact that so many different high-end products have received differing reviews (with some conclusions being strongly at variance with others), without the subjectivist readership protesting on a large scale, is an indication that a lot of those individuals really are not assimilating much of anything at all.

Let's face it, most subjectivist audio writers are to a great extent employed to intensify the prejudices and insecurities, or massage the egos, of individuals who, really deep down, couldn't care less about the realistic performance of audio hardware. Those readers are interested in poetry, not specifications. They want to know that a given piece of hardware imparts depth, spirit, sweetness, meaning, profundity, truth, and soul to a recording—not that it merely reproduces an electrical input signal or even accurately reproduces a recorded event. For those people, intellectualizing about audio is spiritually corrosive.

Indeed, if such readers cared about the reproduction of sound, they would not be captivated by single-ended tube amplifiers and the LP record, nor would they agonize about wire and cable, coat their CDs with oil, or clamp their compo-

nents in heavy equipment racks. As a

ISSUE NO. 25 • WINTER 1998-99 7

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consequence, most fringe-type audio

writers are paid to expertly mesmerize their readers, not give them any kind of information—even wrong information. This is why certain magazines can print pages of test data and then make judgments about the equipment that are totally unrelated to what the graphs indicate, why certain columnists can talk about putting air bladders under amplifiers or rocks on top of them to make them sound better, and why those who review CD players and amplifiers for any number of wildly weird audio magazines can wax enthusiastic about pace, rhythm, and musical truth in their written commentaries. Subjectivist writers are paid to do the same thing music does: tickle the

emotions.

I believe that without the phenomenon of audio-journalistic entertainment, a sizable percentage of the readership of many audio publications would defect (some fringe journals would no doubt be

completely wiped out), and both the soft-

ware and hardware industries (particular-

ly the high-end community) would suffer. In addition, without speculative journalistic entertainment some audio buffs would probably quit the pastime completely. Without the mythology, the hobby itself might shrink to an even smaller size than it is today, although those left behind might gain the hobby a little intellectual respect.

It is unfortunate that this little diversion called audio, which in the beginning, several decades ago, was dominated by the brass-tacks crowd, has allowed this Frankenstein monster to be created. However, we are stuck with it and rationalist enthusiasts like you and a handful of other engineering-oriented types (and me, too, I suppose) will just have to learn to roll our eyes and live with the way things are.

"Men judge of things according to their mental disposition and rather imagine than understand."—Spinoza, Ethics.

Sincerely, Howard W. Ferstler

Tallahassee, FL

I should have been much more specific and precise about planar and line-

source speakers. Imagine a rectangular

listening room one of whose shorter walls is an electrostatic sandwich, from to floor to ceiling and wall to wall, driven in

phase over its entire surface. You would be in the farfield—mono of course—no

matter how close you were to that wall because an unvarying planar wave front would be traveling down the entire length

of the room. The same would be true, but

in one dimension only (mea culpa), of a

floor-to-ceiling line source from which a

cylindrical wave front is traveling down

the length of the room. Yes, Howard, I know that typical free-standing planar speakers and free-standing line-source speakers suffer from various interference effects. I was just trying to emphasize that they represent quite different theoretical models than point-source speakers.

As far as the corner placement of subwoofers is concerned, the wall distances for the 11-inch Sunfire are about half of those for the big subs; in other words, the Sunfire is twice as deep into the corner linearly and eight times as deep volumetrically. I am not enough of a

physicist/acoustician to tell you exactly

how that affects the impedance matching to the air load seen by the driver(s), but I don't have to. The drastically reduced distortion (as compared with placements seeing larger solid angles) tells the story. It's hard to argue with the THD curves.

What is wave launch? I use the term to mean the three-dimensional geometry of wave fronts emerging from a loud-

speaker prior to reflections. In my fairly well-deadened room wave launch defines a considerable part of a speaker's sonic signature; those who live in glass houses will probably agree with you because the specifics of the signature will be lost in the reverberant acoustic soup.

The controversy regarding audioonly vs. home-theaters speakers is, I think, adequately addressed in John Ötvös's letter above, to which I have nothing to add at this point because I basically agree with it.

Your entertaining analysis of the

phenomenon you call The Entertainers

elicits no strong disagreement from me, but I don't believe it is "exactly at dead center. " You say I consider The Con Men to be a larger category than The Dupes, but that's not so. I believe that the majority of the tweako pundits are True Believers, i.e., Dupes. They may wish to entertain while expressing their true beliefs, but their principal motivation is to defend the Truth, smite the Infidel (you and me), and give proof of their exquisite taste and hearing acuity. Most of them are poorly paid; their chief reward is the opportunity to play with expensive toys. But if you happen to be right and The

Entertainers know that it's all just B.S., then they are a subcategory of The Con Men, aren't they?

I love your "depth, spirit, sweetness,

meaning, profundity, truth, and soul" progression, but it also makes me sad. Any audiophile who looks for that in an amplifier rather than in the music itself

is, culturally, a pathetic loser, but you are

right—that's exactly the way so many of

them think. Audio tweakspeak as pornog-

raphy is, you will recall, a concept that

was explored on the cartoon page (1-

900-HOT-HIF1) in Issue No. 21, so you know I'm with you there. On the other

hand, I'm not with you when it comes to giving up—learning "to roll our eyes and live with the way things are." No way, Howard. Spinoza, schminoza, the simple

truth cannot be subverted permanently; it will out in the end. We just have to keep repeating it.

—Ed.

The Audio Critic:

...As you know, I'm a firm believer in the use of double-blind testing, only I use this method with wine, often with interesting results. I'm also personally acquainted with your [Peter Aczel's] honesty, which is impeccable. So when I read that you and your colleagues did not hear differences between CD players, preamps, and amplifiers, I'm certain this is what transpired. I am confused, however.

I also believe in the validity of Bob

Carver's transfer-function test (really a

way of comparing dynamic performance

between dissimilar units) first reported in your journal. If the amplifiers null, then the current and voltage outputs are identical and thus the sound must be as well. There seems to be a basic conflict here: amplifiers that null must sound the same; amplifiers that don't null must sound different, yet I believe you are hearing exactly what you report in your doubleblind tests.

In a similar vein, my experience fif-

teen years ago was that there were sub-

stantial differences between amplifiers in

their ability to drive real-world loads

(leave aside subjective issues of "bet-

ter"). Two loudspeakers (Gayle and the original Sound Labs) that were both difficult for about six prestigious brands of solid-state amplifiers were handled with

aplomb by a Nairn 250, a smaller, much lighter design whose stated purpose was

to drive real-world loads and provide

plenty of dynamic headroom. I'm not

THE AUDIO CRITIC

pdf 9

talking about "liquid midrange," but the result was that the Nairn sounded different. I know this is anecdotal, and perhaps amplifiers are much better generally today, but it seems that the ability to drive complex loads will make a difference in the sound, at least under certain circumstances. I am not suggesting anything magical, simply good engineering, and it is a safe bet to say that the Nairn had a different transfer function than the other amplifiers it was compared with.

The transfer functions don't null— different currents and voltages are being delivered to the loudspeaker, therefore they sound different; in double-blind tests no difference is heard—any ideas on how to resolve this dilemma?...

...Best wishes, Terry McCarthy New York, NY

No dilemma, Terry. Your puzzlement

is based on a false assumption. You write,

"amplifiers that null must sound the same; amplifiers that don't null must sound different." Correction: amplifiers

that don't null will sound different only if the transfer functions differ greatly. The null test is much more sensitive than the human ear; well-designed amplifiers may be slightly different in transfer function but not enough to be audibly different. Our hearing is relatively crude, so we need to listen to, say, a tube amplifier with high output impedance, lots of sec-

ond harmonic distortion, and a rolled-off

top end before we can distinguish it from

a more standard (i.e., neutral) amplifier.

I now have a sneaking suspicion,

unprovable after all these years, that the

dirty little secret of the original Bob

Carver "t-mods" was that the amplifiers sounded indistinguishable from each other even before the transfer-function modifications, at least in the case of solid-state amps. We just didn't have our

level-matching procedures down pat.

(Sh! Don't tell Bob!)

I am perfectly willing to believe that some of those amplifiers fifteeen years ago had trouble driving crazy impedances—but on easier loads they sounded

the same as the Nairn (rhyme unintentional).

—Ed.

The Audio Critic:

I'm an original subscriber to The Audio Critic and have enjoyed every

issue for the past twenty years or so. [We

don't have quite that much mileage on this vehicle; there was an almost seven-

year hiatus in between.—Ed.] During

that time I've noticed many changes in your reviewing perspective, most notably those involving electronic equipment. But while reasons such as double-blind testing have explained some of your changes, there's been one change that I don't believe has been adequately explained. Why do you no longer believe pulse coherence in speakers is audible when you once believed this test revealed the best speakers?

...I may be mixing apples and oranges here, but the only reference I can find that may have led to this apparent shift is cited in Issue No. 16 in speaker reviews by David Rich, where he writes that the "sensitivity of the ear to phase variation remains a point of controversy

{Lipshitz 1982], [Fincham 1985], [Deer 1985], [Greenfield 1990]." In a review of

the ACI Sapphire II in the same issue,

Rich states that the speaker "reproduces

pulses with outstanding fidelity" and that the speaker "achieves good pulse response by using first-order crossover

sections." Yet, in a more recent review (Issue No. 24) of the updated ACI Sapphire III, Rich writes about the speaker as being "phase-coherent (so the tweaks will

respect you)."

Could you please explain this appar-

ent shift in speaker testing and reviewing? Weren't you originally using pulse testing to measure time/phase differences? What were you hearing or measuring in 1977 that you no longer believe you can hear? Do pulse coherence tests

no longer show the time-domain differ-

ences among speakers that can reveal

which are able to make [music sound]... live instead of canned?

Robert Burko Milwaukee, WI

Ah, a very good question—good because it is easy to answer. Pulse coherence is intellectually very satisfying, as it

indicates waveform accuracy. We all want to believe that the output resembles the input in every respect. Obviously, that's always a good thing, never a fault,

as natural to trust as Mom, the flag, and apple pie, so in the early years of The Audio Critic it didn't occur to me to ques-

tion it. The trouble is that we never ran double-blind listening tests to verify our belief.

The researchers cited by David Rich

did run controlled listening tests, however, and pretty much pulled the rug out

from under us. The kind of coherence we

used to test for—between the midrange driver and the tweeter—is definitely not audible. That's no longer open to argument. At lower frequencies the ear is more sensitive to phase.

The coup de grace to the coherence

criterion was actually administered in

1983 by David L. Clark in a not very widely circulated white paper, "Some Experiments with Time" (Syn-Aud-Con Tech Topics, Vol. 10, No. 5, Winter 1983). He reported that at higher frequencies a

phase shift of as much as -2700° was

inaudible to any of his listeners—i.e., indistinguishable from a wire bypass of the delay network— as long as there was

no accompanying frequency response

error. (That's the big booby trap, since

phase shift will change the frequency

response unless the latter is deliberately compensated for.) In 1997 David Clark told me that he has meanwhile carefully trained himself to hear -1000° of phase

shift but still gives up on anything

between that and 0°!

So, we're back to good old frequency response as the acid test and no longer seek the theoretical comfort of coherence, although we 're certainly not against the accurate reproduction of square pulses by a speaker as a techie bonus.

—Ed.

The Audio Critic:

Recently, I was elevated from the post of underpaid prosecutor to that of better-paid judge. Figuring it was time for

a few upgrades, I decided to redo my sound system. Plunging into the endeav-

or with all the enthusiasm of the newly

converted, I began reading Stereophile.

Now one might think that, because I

was a prosecutor for eleven years, I would cast a skeptical eye on the wild claims made by the promoters of High End and tweakdom. Right. I was about as smart a shopper as an eight-year-old set loose in Toys 'R' Us. I bought green paint for my CDs, a "blacklight" to go along with the green paint, and a ludicrous amount of cones, sorbothane thingies, and other useless artifacts. I did everything but bow ritualistically toward Santa Fe and chant, "Harley is God, Harley is God." (Oh yeah, I bought his book. Impenetrable. Now I know why. It doesn't make sense.) Still, there was a wee voice in the back of my mind saying, "Are you

ISSUE NO. 25 • WINTER 1998-99

pdf 10

out of your mind? A demagnetizer for CDs? No use. A junkie is a junkie.

Then I found your magazine at a Denver area newsstand. (Unfortunately, this was on my way back from shelling out $400.00 for new cables.) What a revelation! While it hurt to realize that, yes, I had been suckered by the shills of Santa Fe, I nonetheless felt a certain calm come over me as I read the articles. Sort of like waking from a nightmare—it was very bad, but it's over.

Now, in fairness to Harley et al., I did wind up with a pretty decent system. But I also wound up with various costly pieces of tweaky junk. Were manufacturers in the field of photography (my parttime business) to make the sort of wild

claims made by many high-end manufac-

turers, they would be laughed out of the business. In the real world, companies must make products that achieve identifi-

able, clearly beneficial results, or they go out of business. They cannot rely on consumers "imagining" they see an improvement, with an assist from hacks with a vested interest in advertising dollars. The thought of anyone trying to market seriously the equivalent of "Shakti stones" or "power line conditioners," in a field where they would have to prove the product's worth, is beyond imagining. Yet folks are getting rich, very rich, by convincing people with too much money that their systems are fatally deficient if they don't purchase some bizarre tweak that in fact does nothing.

Your preference for blind testing and ABX comparisons is so obviously valid that there can only be two possible explanations for Atkinson's resistance to the concept. Either he is afraid of discovering that his precious ears are fooling him (and he doesn't seem that stupid but, then, neither do I) or he knows where the money is and wants it (and the consumer

be damned). In the old West, they called

it a medicine show. Step up and buy the

elixir! It'll cure anything!

There is so much I want to ask you, but rather than take your time (which you don't have anyway), please find enclosed

my check for...a new subscription and [all] the available back issues...This is money I don't mind spending.

Also, though I'm not complaining, please keep in mind that not all of us are E.E.s. Some of the technical stuff in Issue No. 24 was way over my head. After all, if I was any good at math and physics, I wouldn't have had to go to law school.

Thanks for your time, and your

magazine.

Very truly yours, Jeffrey S. Ryan Summit County Court 5th Judicial District of Colorado Breckenridge, CO

"Joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons, which need no repentance. " Too bad you didn't discover us sooner. But does it take a lawschool education not to treat incontrovertible evidence against tweako cultism with denial? In this delirious hobby it apparently does—and even a law degree isn't always a guarantee, as the number of true-blue audiophool lawyers proves it. As for the E.E. stuff, we are only mar-

ginally more technical than Stereophile,

if at all. Some statements about audio are

meaningless unless supported with scien-

tific references, but most of our articles

are entirely accessible to the interested

layman. A few people would like us to be

"My First Book of Electricity, " explaining what an ohm is (or a µF or a dB) while reviewing CD players and loudspeakers, but that isn't realistic. There are plenty of elementary textbooks in the libraries and bookstores.

—Ed.

The Audio Critic:

Greetings from the frozen north! Thought I would [share with you some experiences] after years of watching tweakers "modify" circuits. I foil the buggers by potting the circuits of the Morrison preamp. Once saw one of Stew Hegeman's Hapi One phono stages butchered by a wacko. He had replaced all of the parts in the EQ with the usual magic and mysterious components made from yak phlegm. The tolerances were all over the map, but apparently this sort of mundane stuff doesn't matter.

A dealer who was an accountant by trade regularly burned his fingers when "doing the mod" on very expensive amps. One day I watched him solder a film cap with extremely long leads from the negative lug of the large electrolytic on the B+ side to ground. He did the same on the B- side except, of course, from the plus lug to ground. For installing two film caps from ground to ground he charged $400. As later heard via the grapevine, the customer was in seventh heaven over the sonic improve-

ment.

I once sold one of my earlier phono preamps to an outfit called The Tweek Shop somewhere in California. The unit was returned after some time for repair. After lifting the cover I discovered that the unit had been "modified"—parts changed all over the place, complete with melted capacitor casings and several cold-soldered joints. They had the nerve to return the unit, bitching about its performance.

News flash! The audiophile I call

Crazy Howard bought $3600 worth of

Shakti antivibration-antimagnetic-field-

radiation blocks. He wouldn't buy my $800 (Canadian) line stage even though he thought it sounded better than his Jadis but wasn't quite as musical. Uh-huh.

A few years ago a seminar was held on interconnect cables at a Toronto stereo shop. The object of the exercise was to discover if the consumer could pick out the difference between interconnect cable A and interconnect cable B. A room full of keen-eared audio buffs, including a contributing equipment reviewer of

Stereophile, took part. Unbeknownst to

anyone, cables A and B were identical.

Those who were objective simply

shrugged at the end and confessed that they heard no difference. The neurotics, however—blessed with golden ears and some sort of mystic powers—were able

to distinguish subtle differences even

when the switch was thrown from cable

A to cable A. In other words, when there was no switching between cables at all! Yes, sir! The half dozen or so huddled in a scrum—in the "sweet spot" of course. Furrowed brows, and frantically scribbling notes, and listening soooo hard! This display was a very valuable one. It quickly sorted out the objective listeners from the wackos. And yes, the equipment reviewer was among those who heard things that weren't there. These same people vote in elections.

Following the great interconnect survey, I wanted to investigate further the ability of audiophiles to determine the "sound" of a particular set of interconnects when used in their own system. Two sets of one-meter pairs were fitted with decent locking RCA plugs. One set was covered with blue heat-shrinkable tubing and the second pair with green. Other than colour, both cables were identical.

Once again the objective folks reported that "the goddamn things sound

THE AUDIO CRITIC

pdf 11

the same to me!" But the rabid audio neu-

rotics, by golly, were not fooled. The differences they heard, though subtle, were unmistakably there and were ranked in terms of "dynamic shadings," "musicality," "coherence," and Christ knows what else. One character wrote a full-page report on the differences between the cables, describing sonic traits never before or since heard of. Remember, the only difference between the two sets was that one was blue and one was green.

Years ago, a friend of mine had the misfortune of assisting a distributor at a hi-fi show. After a boring day of handing out brochures and answering silly "How many watts is that speaker?" sort of questions, my friend decided to stir things up by starting a rumour. It went as follows: whenever a piece of equipment was described, the pronouncement was added, "the umbrella effect is reduced or eliminated." The degree to which it was altered was determined, of course, by careful engineering. Accompanying this claim, the hands were always moved in an arc-like fashion, much like the shape of an umbrella. The person listening to this load of horsefeathers would eagerly nod his head, understanding full well the advantages of taming the dreaded "umbrella effect," and thank heavens here was an outfit at last facing this dilemma head on!

The following morning, in the hotel dining room, there was a sea of assholes arcing their hands in the fashion of das bumbershoot, discussing the advantages of the elimination of the newly discovered source of distortion.

Years ago, I took a stereo nut to his

first live symphony. The program was a lively one and included a Borodin piece in which all the players dug in several times in a walloping fortissimo. Despite the fact that we were seated in row five, my colleague announced afterward over a couple of pints that he thought that the live performance would be much louder. This same individual spent his spare time advising other people on how to chose

stereo gear...

The Chinese Audiophile Club meets on the first Monday night of the month in Toronto. I was invited as a guest a few years ago by a Mr. Ng to observe the

shenanigans that went on. An outfit called Shun Mook (I think) makes discs, pucks, cones, or whatever, out of weird and exotic wood—ebony, rosewood, padauk, purpleheart, etc. The entire meeting that

night revolved around the careful listening by the members to the different wooden devices tucked underneath the CD player. The various timber types were actually ranked in terms of being able to "bring out the, best microdynamics" or which one has the "best soundstaging." I suggested that the maple cones, since there was probably a trace of maple syrup, made for a slightly sweeter sound. One of the club members nodded in agreement. I graciously thanked Mr. Ng and beat a hasty retreat. (The calming effect of a Guinness cannot be overrated.)

How come the wackos can hear the differences between blue and green and yet cannot hear a -3 dB rolloff at 10 kHz? How can they hear the difference between oak and ebony cones but cannot grasp the concept of accuracy?

When confronted with virtually distortionless electronics, they always play their trump card. It's not as "musical" as their wretched 10% THD favourites.

Am I pissing in the wind? Should the output of a preamp/power amp not be a replica of the input? Is the "musicality" not the task of Mozart, Bach, and Beethoven?

I could go on for pages but it's just too depressing.

The reason for sending The Audio Critic the line stage is to get the idea across that the problem of getting a signal from CD player to power amp is relatively simple, and bog standard parts can be utilized. If just one young audiophile is kept from the clutches of the wackos, it'll make my day!

Regards, Don Morrison Morrison Audio Toronto, Canada

You've made your point, Don. To me the "umbrella effect" alone was worth the price of admission. That I'm also in agreement with your engineering philosophy should be evident from the review of

your preamp in this issue.

But tell me, doesn't "bog " mean the toilet in British army and schoolboy

slang? I hope "bog standard" isn't some-

thing off-colour (to use your bloody

spelling, mate).

—Ed.

• • •

To conclude this column, here is a business letter (as distinct from a letter to the Editor) illustrating a fundamental reality of The Audio Critic's existence and

an important difference between it and other audio magazines.

Dear Peter:

...I must apologize but we have, with great consideration, decided to refrain from having you review the pieces [Polyfusion Audio CD player and D/A processor] at this time.

Also, again with careful consideration!, we have decided to NOT advertise in your upcoming edition of The Audio

Critic...

I am sure you are puzzled over this change of heart. This is largely due to our review of some of your statements in the last issue about the amplifier's "vastly exaggerated" importance and CD players and preamps mostly sounding the "same, regardless of price."

We, as a manufacturer of High-End audio gear, obviously disagree with your observations. We certainly respect your right to voice your opinion—but any participation by us with The Audio Critic would be non-sensible and non-productive.

Thank you for your understand-

ing.... Perhaps in the future, under differ-

ent theologies, our paths may cross again.

Sincerely, Rick Ellis

Sales/Marketing Manager Polyfusion Audio Lancaster, NY

What a nice, concise statement of the high-end audio industry's unshakable belief that the truth is bad for business!

A number of important corrections

are in order. To wit:

Our statements regarding the sound of purely electronic signal paths are not mere "observations" or "opinions" or

"theology. " They are reiterations of incontrovertible facts of electrical engineering and psychoacoustics as attested by authorities with the highest scientific credentials.

Secondly, sound is not the only reason to buy high-end audio electronics. To use an automotive analogy, a Chevrolet will get you to the mall as quickly and reliably as a Bentley, but that perception hasn't killed too many Bentley sales.

Lastly, an advertiser wishing to be

"productive " needs a publication with a demographically optimal readership, not with a groupie philosophy. Take it from an old Madison Avenue professional.

—Ed.

ISSUE NO. 25 • WINTER 1998-99

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The Good Guys in the White

Hats and the Bad Guys in the Black

Hats: Continued

By Peter Aczel

Editor and Publisher

You will need Issue No. 24 to begin this expanding list of good and

bad audio people at the beginning and understand it as completely

as intended.

The article about the White Hats and Black Hats of audio drew by far the strongest reaction, from both our friends and enemies, among all the items in our last issue. It appears that the prurient interest exceeds the technical and musical interest even within our very special circle of readers. (I knew it all along.) Nominations for additional white and black Stetsons kept pouring in, but most of them were not white enough or black enough to qualify, being various shades of gray. (See also page 14, bottom right.) As an example, take someone like Bob Stuart of Meridian Audio. He is without doubt a gifted, scholarly, and highly credible technologist, one of the pillars of the audio engineering community. Yet he has also been the high priest of a contingent of English tweaks who hear things that don't exist. He is certainly not a Black Hat in the Bruce Brisson sense, but I have qualms about placing him in the White Hat category. And so it goes.

Be that as it may, there were clearly some omissions in the original list. Here are a few names that should have been included—and, of course, sequels are to be expected.

More White Hats

It should be pointed out that the White Hats are generally not as visible as the Black Hats. You have to look for good things that are happening in audio and find out

who is behind them. Unlike most of the Black Hats, these

good guys are often modest and don't promote themselves.

Paul Barton (PSB Speakers)

Another Canadian. (They have disproportionate representation on the White Hat roster, possibly because the snake-oil tradition is not as deep-rooted in their mercantile culture as in ours.) Paul Barton's compatriot John

Ötvös, maker of my reference speaker (Waveform Mach

17), once told me that the PSB Stratus Gold would be his

choice for his own use among other manufacturers'

speakers. That's good enough for me, although I hope to

test one soon in our laboratory. In any event, Paul has

been known to me for years as an absolutely straight, sci-

entific, nontweako, truth-telling engineer, devoted to integrity in speaker design. That gets him a White Hat.

James Bongiorno (Spread Spectrum Technologies, Inc.)

The badass boy wonder, now aging, of the electronic engineering community. Those of our readers who go back to the '70s probably remember my various run-ins with Jim, but that doesn't change the fact that he is a highly original and ceaselessly creative circuit designer, not

only in audio but also in RF. Those long-ago SAE, GAS,

and Sumo topologies Jim had cooked up turned out to be

classics, very different from the expected and clearly

superior. His patented but never used FM detector circuit

is truly innovative. ("If someone actually manufactured this tuner, it would rule the world," says David Rich.) Jim is currently unaffiliated (the company name above is that of his consulting firm) but he has some big plans. He recently sent me a long, rambling, and barely legible manuscript (totally illegible to my scanner software) that I hesitate to publish because it withholds the main piece of information that would make it truly interesting and important. Jim claims that the diff-amp (differential amplifier) input in solid-state ampifier design is antiquated, passe, obsolete, and that he has a more advanced solution. What precisely? He won't say; he just teases us with some hints. (He probably thinks the plagiarists are lying in wait, salivating.) The thing is—I believe him because I believe in him. He is one of the few audio people capable of advancing the art and not just shooting the bull (at which he is also very good).

• • •

Editor's Note: Some time after the above was written, there came the news that Jim Bongiorno was very sick. He has constantly recurring and now life-threatening liver problems that go back many years, and he needs some very sophisticated and costly medical treatment for which he has no insurance. Eventually he may have to undergo a liver transplant, which is contingent on organ availability as well as funds. We are talking about six-figure

THE AUDIO CRITIC

pdf 13

sums here, totally beyond Jim's means. Contributions are being solicited to The James Bongiorno Medical Trust Fund, Bank of Montecito, Santa Barbara, CA 93140. The

contact for the fund is Ms. Krissi Wray at (805) 564-0220.

Fred E. Davis (independent consultant)

There have really been only two sane, scientifically modulated voices amidst the strident voodoo chants on the subject of wires/cables: that of Dick Greiner, already designated a White Hat in the last issue, and that of Fred Davis (in the AES Journal, in Audio, and elsewhere). Modesty prevents me from naming a third voice—never mind. Fred Davis tunes the RLC differences and their audibility/inaudibility even finer than the rest of us rationalists but leaves just as much egg on the voodooists' faces. Good man, good exegete.

Bill Dudleston (Legacy Audio)

The lantern of Diogenes would have revealed him to be an honest audio designer. His top-of-the-line loudspeaker systems (not yet tested here) are very highly regarded by all the experts I respect and, best of all, cost about half of what they would if distributed through dealers, thanks to Legacy's factory-to-consumer marketing. What's more, he is a straight talker on all technical matters. Good engineering, good value, and no B.S. add up to a White Hat in my book. (I have charitably decided that the very few and far-between "eyebrow raisers" in the Legacy literature must originate from someone else in the company.)

David Griesinger (Lexicon)

The man who knows more about digital signal processing for multichannel sound than just about anyone

else. You could say he wrote the book. He is the engi-

neering community's spokesman on the subject; they look up to him, and so do I. Ask him about psychoacoustics, too; he'll tell it like it is. Also read the Lexicon DC-1 review in this issue.

Tomlinson Holman (TMH Corp., formerly Lucasfilm)

A very serious audio technologist by anyone's reckoning. Remember the Apt/Holman power amp of the early '80s? It was the smartest, most completely thoughtthrough design of the era (and I didn't even fully appreciate it at the time). Fast-forward to THX, into the later '80s and right up to the present time. That was entirely Tom Holman's doing, and even if the THX system has certain promotional/commercial undertones it has undeniably helped to stabilize the surround-sound scene and set a minimum performance standard. Do you like the sound of the Indiana Jones movies? Tom Holman was in charge of the entire technical infrastructure there. Anyone who has attended a few Audio Engineering Society conventions can testify to Tom Holman's intellectual leadership. The world of audio would be quite different without him.

Dr. Roger West (Sound Lab, Inc.)

Definitely the most credible of the electrostatic loudspeaker gurus. He has never denied the disadvantages of the electrostatic design approach; he just believes that the advantages are decisive. His top-of-the-line Sound Lab Ultimate 1 overcomes the disadvantages through brute force but still doesn't carry a cynically inflated price tag; his smaller models are honestly engineered and honestly priced tradeoffs. David Rich is a big fan of the entrylevel Quantum; I myself have tested the next step up, the Dynastat, but want to look at a more current production version before publishing a review. In my book, Roger West is "Mr. Electrostatic USA" on account of his scientific integrity.

More Black Hats

If this is the part you started to read first, you have a dirty mind and are directed to go back to the White Hats and start there. It is with considerable sadness that I list the names below—or do you think I just want to give you a cheap little frisson of Schadenfreude?

George Cardas (Cardas Audio)

Worse than Bruce Brisson? That's how some snakeoil monitors rate him. He is certainly a major example of the breed—the cable peddlers who use pseudoscience to

justify their insanely inflated prices. Cardas cable is

designed with "Golden Section Stranding"—strands differing in mass in accordance with a Fibonacci sequence or "Golden Ratio"—in order to eliminate "resonant multiples in the conductor." This is such garbage in terms of real-world audio engineering that Pyramid Power is the pinnacle of applied science by comparison. Look up www.cardas.com on the Web and laugh your head off. Or cry.

Martin Colloms (Stereophile, HFN/RR)

A particularly opprobrious Black Hat because he possesses sufficient technical knowledge and scientific logic to be totally aware of what he is doing to his gullible readers—filling their heads with tweako garbage. He has the ability to perform all the laboratory tests this publication does, and then some, after which he will report that cable A has much better rhythm and pace than cable B and that some loony single-ended triode amplifier with oodles of distortion is the cat's meow. His hypocrisy quotient is right up there with fellow Brit John Atkinson's, and so is the technocultural damage he does.

Martin DeWulf (Bound for Sound)

Another audio writer/editor opposed to the findings of practitioners who, unlike him, are trained in science. Of course, one can never be sure whether such marginal pundits are sincere or not. Unless he keeps claiming to hear differences that in reality do not exist, the expensive toys he likes to play with and write about might stop coming. He has nothing to offer a high-end manufacturer

ISSUE NO. 25 • WINTER 1998-99

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except his exquisite auditory aperçus and facile audiosalon prattle, since he lacks the technical wherewithal to come up with constructive criticism in engineering matters. His limitations lock him into a groupie position. A guest article by DeWulf in a recent issue of the The

Absolute Sound, listed as a "think piece" in the table of

contents, rehashes without any evidence of thinking all the tired old sounds-the-same/no-it-doesn't issues that have been laid to rest, over and over again, by some of the

most highly qualified experts in audio and psychoacoustics. My name appears in the article, as well as in a followup exchange of letters in a later issue, as a centerpiece of DeWulf's demonology. He cannot forgive my long-ago defection from the subjective reviewing of purely electronic signal paths. What he doesn't seem to understand

is that some of us are capable of gaining new knowledge and new insights over the years, not just weight.

Michael Green (RoomTune by Michael Green Designs)

The room-treatment charlatan extraordinaire. His only saving grace is that, if you fall for his cockamamie theories and buy his gizmos, you are out less than $1K, in most cases. Does that make him less of a Black Hat? I don't think so; antiscience is antiscience, regardless of the price tag. Some of his little Velcro-fastened dinguses aren't big enough to affect the acoustics of an airplane toilet, let alone the sound of a big listening room. Sure, when he hands them out free of charge to exhibitors at a show, you see them used in the rooms and you think they are there for a purpose, but think again—who says no to a freebie? Especially when it takes up little room, is basically harmless, and comes from an affable chap with Jesus hair? (All that hair will fit only into a size XL black hat.)

Benjamin Piazza (Shakti Audio Innovations)

Designer and promoter of the Shakti Stone, a.k.a.

Shakti Electromagnetic Stabilizer, a mind-boggling

example of the tweako artifact that does nothing and of

the gullibility of the high-end audio freak. A Shakti Stone is a magic brick, $199.99 each (but you must buy several), which you simply place on top of an audio component

to defeat electromagnetic interference (EMI) and thereby

improve the sound. Whatever is inside the inextricably

potted brick—who knows, maybe it's all kinds of passive circuitry as Piazza claims in his technobabbling "white paper" or maybe it's bat guano—that's not how it's done by scientifically accountable engineers even where EMI is a problem (as it rarely is in audio). You've seen this

before—the bold leap from an esoteric but technically

defensible buzzword to a fatuous marketing non sequitur.

Question: What's the difference between a Shakti Stone and a Shun Mook Mpingo Disc? Answer: Who cares?

Jonathan Scull (Stereophile)

The audio journalist who brought tweako subjec-

tive reviewing to a new height of unbridled self-indul-

gence and foppish silliness. I think even John Atkinson must feel slightly nauseated as he edits JS's fulsome copy. It is significant that the most outrageously tweaky products that come in for review are usually assigned to JS. If they ever reviewed a liquid-nitrogen-cooled platinum power cord, JS would be the reviewer, and the name of his wife Kathleen would be invoked to corroborate his exquisite sonic perceptions. To me he represents the ultimate in hokum, self-congratulation, and unaccountability.

Dr. Yu Wah Tan (Shun Mook Audio, Inc.)

Assisted by Bill Ying and Andy Chow—and I don't know (and don't care) which member of the trio is the originator of the steer droppings they hype. Maybe it all comes from a secretly located stockyard in Chinatown. All I know is that "Mpingo" (ebony) wood pucks placed in strategic spots on and under your audio equipment don't accomplish anything other than fattening the earlyretirement fund of the Shun Mook phonies. Actually, anyone so stupid as to spend money for these worthless New

Age fetishes deserves what he is getting. Thus, in the final

analysis I'm all for Shun Mook because their efforts help to identify and isolate the irredeemable idiots in our

midst. (See also Don Morrison's letter in the "Box 978" column in this issue.)

The Academy Advancing High End Audio and Video

Not an individual but an alliance of manufacturers,

most of whom make their living with overpriced tweako products. I say most, not all, because paradoxically there is a small sprinkling of White Hats among them, strictly for self-serving political reasons, in the face of fundamental differences in engineering doctrine. As an organization, however, they stand for all the antiscientific voodoo and subjectivistic rubbish that this publication fights against. Their members banded together to lobby for the audibility of the inaudible. They definitely don't want you to know that bits are just bits, that wire is just wire, that vacuum tubes are horse-and-buggy devices, that magic objects placed on top of an amplifier can't make it sound better. They want you to be a True Believer. The Stetson factory never made enough black hats for all the heads that are screwed on wrong in this self-styled "academy."

A New Category: Gray Hats

This is a kind of purgatory for seemingly contrite

Black Hats on their way to possible redemption.

Corey Greenberg (Audio, Stereo Review)

When I classified Corey as a Black Hat in the last issue, I pointed out his potential for rehabilitation in an improved intellectual environment. I swear he must have listened to me because at Hachette he is definitely cooling it with the coolo lingo and unbridled subjectivism. He is doing good work. That pearl gray Stetson is you, Corey.

THE AUDIO CRITIC

pdf 15

How to Be a

Sophisticated Audiophile and

Resist Trendy Stupidities

By Peter Aczel

Editor and Publisher

Are you a new reader of our publication? Or a regular reader looking for more let's-get-down-to-basics information? This is addressed to you (but it won't hurt the more advanced aficionado, either).

Serious thinking about any subject begins with the irreducible fundamentals. Why would any sane individual want to get involved in the finer points of audio technology, i.e., be an audiophile? What is the purpose of it all?

The obvious purpose is music on demand in the home, with a sound quality as close to the real thing as possible. The trouble is that the obvious purpose of anything is not necessarily what is served by its actual implementations. For example, the obvious purpose of a very expensive restaurant is great food, but there are some that serve so-so food and are frequented mainly for lifestyle affirmation and celebrity watching. By the same token, there are people who don't really like music but own $200,000 sound systems. I wouldn't know how to advise such people, although they sometimes ask me.

Anyone about to spend a significant amount of money on audio equipment should, as a first step, just stop and think for a few days. Where are you headed? What do you hope to accomplish with your purchase? If you are planning to listen to a lot of music and want it to sound as good as possible, that's one thing. If you want to turn a large room in your house into a movie theater, that's another thing (although a dual-purpose solution is not out of the question). If the orthopedic surgeon down the road owns a Ferrari and you want to one-up him with your new audio equipment, that again is a different ballgame (which I won't help you play). Whatever your goal, you must be able to define it, otherwise you will be all over the place in your buying decisions and probably end up frustrated. That goes for techie types as well as novices.

Here I am going to assume that you love music, own or plan to own a lot of recordings, know what live music sounds like, and have no special audiophile agenda. (I shall deal with the more common agendas, dogmas,

fetishes, and manias, but I know you are unlikely to listen to me if you have already been co-opted.) The highest form of audiophilia is knowing how to obtain optimum results in the listening room without any concern for the audio-salon ideologies of the moment.

There. I said "room." That's where the serious thinking must begin. If your room is small, you must lower your sights. Reproduced sound of great textural and timbral refinement is achievable in a small room, but a truly life-sized, spacious, authoritative sound with untrammeled dynamics is not—not even if you throw money at it. (Years ago, Harry Pearson of The Absolute Sound—and now also Fi—became the laughingstock of knowledgeable observers when he flaunted the original, monstrously large and expensive Infinity IRS loudspeaker system in a phone-booth-sized room in his Long Island house.) Not that a large room guarantees good results. If your room is one of those architectural prize winners with huge undraped picture windows, a bare terrazzo floor, and sparse furniture, you can expect dreadful sound in it even if it is large and has a cathedral ceiling. For the best possible sound, you need a room that is both large and welldamped. How to treat a room for optimum damping is a basic question beyond the scope of this article, but there is no dearth of information on the subject in books and magazines. Here I merely want to emphasize that "think room" should be the watchword of the enlightened audiophile, whether starting from scratch or just planning

improvements.

About Loudspeaker Systems

If you believe your listening room is all it can be,

the loudspeaker system is what you must think about next—and most carefully. Don't let any tweako/weirdo audio cultist tell you otherwise (even if he has a byline in

ISSUE NO. 25 • WINTER 1998-99

pdf 16

a magazine or owns an audio store): the loudspeaker, in combination with the room, will determine the overall

sound quality of your system, not the electronics. If you

are vague or cavalier about your choice of speaker and terribly intense about the amplifier and other electronic components, you will be joining the great brainwashed who pour their money down the sinkhole of a fantasy market. If the only thing you remember after reading this article is that the loudspeaker rules, my effort will not have been wasted.

Unfortunately, there are very few genuinely accurate speaker systems at any price, let alone under $1000 or even $2000 the pair. By accurate I mean that the output of the speaker resembles its input to a high degree, over a reasonable solid angle in front of the speaker. If that seems like an oversimplification, you will find more detailed and more finely differentiated explanations in the loudspeaker section of nearly every issue of The Audio Critic. One way to plan the purchase of an accurate speaker system at a less than scary price is to give up the deepest bass temporarily, settle for a superior small or medium-sized loudspeaker model initially, then acquire a high-quality subwoofer (or two) at a later date. This is the crucial crossroads in system planning or upgrading; it is very easy to mess up here and set out in the wrong direction. On the other hand, once you have the right speakers, it is very difficult to screw up the rest of the system because honest values in electronics are readily obtainable today; your choices are far from limited.

Pitfalls to Avoid

This is a basic orientation article, not an equipment

survey, so I am not going to make specific speaker rec-

ommendations here, but I do want to point out certain common pitfalls and obfuscations you are likely to encounter in your search for the right speaker system. First of all, beware of ultrahigh-priced speaker cables. That whole industry is a fraud. There is no reason to pay more than a dollar a foot, and even that is probably overkill. (For example, good commercial-grade RG-8 coax cable, which is reasonably low in both inductance and capacitance and can be used with the center wire and the shield as the two loudspeaker conductors, costs 69 cents per foot at Radio Shack.) I recommend that you read the wire/cable article in Issue No. 16; it will keep you out of the clutches of the cultists and charlatans.

You will also avoid paying a double price, for whatever speaker cable you might choose, if you eschew the biwiring fallacy. Even enlightened audiophiles fall for that one, despite the fact that it defies one of the basic laws of physics, the superposition principle. As it relates to electronics, the superposition theorem states that any number of voltages applied simultaneously to a linear network will result in a current which is the exact sum of the currents that would result if the voltages were applied individually. If you believe in science, you cannot possi-

bly believe in the biwiring ritual. Note that I am talking about biwiring, not biamping. (The latter is not without

justification in some instances, although its full benefits

are obtainable only with a system driven from a line-level electronic crossover—meaning no passive network connected to the drivers.) Note further that biwiring is quite harmless even though nonsensical. That otherwise reasonable loudspeaker manufacturers recommend it shows how intimidated they are by the prevailing tweako market forces.

What kind of crossover design is best is another

subject replete with tweako booby traps. The first-order

cultists will tell you that only 6-dB-per-octave (firstorder) crossover slopes are any good because they sum to a coherent waveform and can pass square waves. The trouble with that theoretical advantage is that (1) it is only true at the "sweet spot" and (2) you can't hear it, as David Clark and others have demonstrated over and over again. High-order slopes, on the other hand, reduce distortion in the stopband, permit better power handling, and in most cases yield a less "lobey" response off axis. My experience has been that 24-dB-per-octave Linkwitz-Riley crossovers are the best (with the possible exception of Rich Modafferi's Infinite Slope configuration, still in very limited use) and that electronic crossover units are preferable to passive networks. In any event, do not opt for a speaker just because it has a first-order crossover and no other compelling reason.

There is also the matter of speaker stands. Small speakers need to be raised off the floor to listening height, no doubt about that, but the stands need to be merely solid and stable, not necessarily gyrostabilizer platforms. (I exaggerate only slightly considering the techie-phony designs out there that sell for big bucks.) The big spikes that are de rigueur on high-end stands will prevent rocking on a thick carpet but on a bare floor they are as useful as teats on a bull (not to mention lethal to polished wood flooring). Be sensible in your selection of speaker stands;

there is nothing more there than meets the eye.

One more word of warning about loudspeakers. Be aware of the shortcomings of unconventional transducer technologies, i.e., other than electrodynamic direct radiators. Some electrostatic loudspeakers offer very beautiful sound, but only the largest (such as Dr. Roger West's two

or three biggest Sound Lab models) have adequate power handling at realistic playback levels with dynamic program material. Horns handle power with aplomb but with rare exceptions have highly colored response. As for sci-

fi solutions, such as ionized air, acoustical heterodyning,

rigid sheets, etc., you are on your own and should expect

no encouragement from me, although it is conceivable

that one of today's insufficiently debugged exotic designs is the wave of the future.

As for multichannel setups, the ground rules still apply. A good loudspeaker is a good loudspeaker, whether it handles your front left, rear right, or center channel.

THE AUDIO CRITIC

pdf 17

With a good subwoofer in a 5.1 system, the bass capabilities of the surround speakers are not all that critical, even though in the Dolby Digital (AC-3) mode all five speak-

ers receive a full-range feed. Some compromise in size

and bass extension is practical and reasonable for the center and rear channels in most cases, but the up-to-date approach is to avoid dinky little satellite-type speakers altogether. Should a speaker design be optimized differ-

ently for home theater than for music? I hold with those

who feel that the question is more political (or ecclesiastical?) than practical, but I am not about to question the Tom Holman doctrine when it comes to a THX-calibrated home theater for movies only. Ask me again when

every home has a dedicated media room. For now, my cri-

terion remains the sound of music, not the localization of

dialogue or suchlike.

Fact and Fiction in Audio Electronics

Willy-nilly, we come to the electronics from which the speakers are fed. I put it that way because I dread the unavoidable debate about vacuum tubes versus solid

state. It is not an intellectually respectable debate in the late 1990s, any more than (let us say) typewriting versus

word processing. To have to sermonize on the subject is a professional embarrassment. As I have said many times before, there is nothing wrong with correctly designed

vacuum-tube equipment if you already own it; it will in all likelihood sound just fine (unless it was deliberately designed to tweak the signal rather than to reproduce it accurately). But—to go out today, in the golden age of sil-

icon, and spend big bucks on new vacuum-tube equipment is the height of folly. If the tube equipment happens to be a single-ended triode amplifier, then folly is too weak a word; idiocy would be more appropriate. Anything that vacuum tubes can do, solid-state devices can do better, more reliably, and at lower cost. Even the deficiencies of vacuum tubes, such as relatively high second harmonic distortion, can be mimicked by solid-state circuitry if the designer happens to like the euphonious coloration that results.

When it comes to choosing solid-state electronics, another debate rears its muddled head. Does a high-end (i.e., Krell, Mark Levinson, Spectral, etc.) power amplifier or preamplifier sound better than a typical midpriced (i.e., Pioneer, Sony, Yamaha, etc.) unit? The educated answer is—why should it? The midpriced equipment also has high input impedance, low output impedance, flat frequency response, low distortion, and low

noise—and that is what we can hear. There is no such thing as an effect without a cause, and there is nothing to cause the high-end equipment to sound better. Needless to

say, I would rather have a Krell than a Pioneer as a birthday present, for reasons that have nothing to do with the

sound. What reasons? Better build quality, greater reliability, more beautiful appearance, better retention of

value, greater pride of ownership, more attentive treat-

ment by the company in case help is needed—should I go

on?

I am convinced that the myths of one amplifier "blowing away" another in a side-by-side listening test are mostly due to the difficulty of matching levels within ±0.1 dB. It is a fussy and boring process that tries your

patience, even if you have the proper equipment to do it

with. When the levels differ by as little as 0.25 dB, there

is an audible difference, which will be immediately interpreted by some audiophiles as a blow-away. Of course, there are those who can clearly hear a difference in an A/A test as long as they think it is an A/B test. (I have tried that dirty trick on a number of 'philes.) Trust me, no one has ever, ever distinguished two properly designed amplifiers or preamps by their sound alone in a valid blind test. So—the question to ask is not how the equipment sounds but how it meets your goals and satifies your needs. You need a more elaborate array of controls on your preamp if you have a complex sound system than if you have an extremely simple one. You need more watts out of your power amp in a large listening room than in a small one. You need better build quality if you change your system every ten years than if you change it twice a year. And so forth. It is basically common sense.

Are there any fictions, cults, manias, and fads to guard against when choosing solid-state audio components? Nothing as grotesque as the single-ended triode craze, but certain fahionable buzzwords should automatically activate your B.S. warning light. (Just the warning light, not necessarily the B.S. shutoff.) For example, dis- crete circuitry isn't necessarily better than high-quality op-amps. FETs aren't necessarily better than, or even as good as, bipolar tansistors for a given application. Class

A isn't necessarily an indication of superior quality. Low

feedback, or zero feedback, is often a less desirable design

approach than high feedback, correctly applied. Polypropylene capacitors do not "sound better" than less costly capacitors, correctly used. (See also the article on high-end prejudices in Issue No. 24, pp. 16-23.) My pet peeve is the word speed when applied to audio electronics. Those who use it think they are being very cool, very

professional-sounding, but actually they betray their

ignorance. All electronic signal paths that are dead flat to, say, 22 kHz have unlimited "speed" (which in my book is

just another way of saying "bandwidth") for audio purposes. I defy you to distinguish supposedly "fast" and

"slow" amplifiers from one another in a blind test.

When it comes to multichannel AV electronics, there are genuine differences, and not only in watts per channel—that's the easy part. The control circuits range from ultrasophisticated digital, with highly advanced processor chips, down to yesterday's leftover analog with minimal digital implementation. Here you need expert help, which is generally not available from the dealers and certainly not from the tweako magazines. We have

(continued on page 40)

ISSUE NO. 25 • WINTER 1998-99

pdf 18

Then I bought one of those

single-ended triode amplifiers

the audiophile magazines are

raving about.

Now I pull my tubes and

have them tested every three

or four weeks. I put them

back and have the service

guy check the bias.

The tube revival saved my

life. I'm a born-again

audiophile.

18 THE AUDIO CRITIC

My life was

empty. I had

nothing to do

but listen to the

damn music.

I was happy when

surround sound came

because I could fuss for weeks with speaker placement. But then my wife put her foot down and said the

room will absolutely not

be rearranged again.

Then came

CD and

spoiled all

that.

But we still had those great

tone arms that let you

change the vertical

tracking angle. I used to

fuss with that for hours.

And I kept the stylus clean

with a tiny sable brush.

I'm one of the

old-time

audiophiles.

Back in the vacuum-tube days, I used to pull my tubes and have them checked on a

tube tester every three or

four weeks.

One of my tube amps

had front-panel bias adjustment—/ used to fuss with it for hours.

Then came solid

state and spoiled

all that.

In Your Ear

pdf 19

About Minimonitors,

Subwoofers, and Full-Range

Systems In Between

By Peter Aczel

Editor and Publisher

Size is what mainly determines how a speaker system is designed, and there are always many possible engineering solutions in every size category. Here is a sampling of current design practice.

Our readers must be reminded, and should understand, that we cannot go back to square one in every issue and explain our philosophy of loudspeaker evaluation over and over again. Ideally, you should have a complete set of our publication beginning with Issue No. 16. If that is not practical, go back at least four or five issues if you are a new reader. Not that there is anything in our procedures that radically departs from established scientific practice, but we are constantly bombarded with questions that have already been answered in our pages. (Back issues are available at the same rates as new subscriptions.)

Here I want to add that the various sophisticated computer programs currently available for loudspeaker design—crossovers, woofer enclosures, simulated system response, etc.—have virtually eliminated truly godawful speakers. There appears to be a slow convergence toward relative accuracy, although one still runs into some willful and often selfcontradictory design tradeoffs.

There has also been a significant improvement in the raw (OEM) drivers available to loudspeaker manufacturers from the various American, European, and Asian rawdriver houses. Nasty ringing in response to tone bursts has become so rare that I no longer do toneburst tests routinely, only when I suspect energy storage problems. Advances in materials technology and CAD must be credited for this. Frequency response and distortion specs are also better across the board, even in massproduced drivers. One more reason for the aforesaid convergence.

Bag End Infrasub-18

Bag End Loudspeakers, Modular Sound Systems, Inc., P.O. Box 488, Barrington, IL 60011. Voice: (847) 3824550. Fax: (847) 3824551. Email: info@bagend.com. Web: www.bagend.com.

Infrasub18 powered ELFsystem subwoofer, $1495.00. Tested sample on loan from manufacturer.

In Issues No. 21 and No. 22, David Rich and I covered in considerable detail the ins and outs of the Bag End ELF system and the design of Bag End subwoofers. At that time Bag End was a brand widely recognized in the field of professional sound but not in the audiophile world. Since then the company has been exploring new directions and has developed a product called Infrasub18 for the highend consumer market.

The Infrasub18 rolls the Bag End concepts into a single integrated package. The unit incoporates an 18 inch driver in a 3cubicfoot sealed box, a 400watt power amplifier, and a somewhat simplified version of the ELF

electronics. The power amplifier is something new; the prosound users had to supply their own. Its 400watt

continuous power rating is presumably into 4Ω., which is the nominal impedance of the EL18P driver. The builtin ELF module does not have to be as flexible as the separate prosound version, as it is dedicated to a single sub woofer. At the early 1997 introductory price of $1295.00, this package represented outstanding value. With the $200.00 price increase, the Infrasub18 is now positioned at the same price point as the topoftheline Paradigm

product, and the criteria inevitably change.

I do not intend to explain the ELF system all over again in this review. For that you will have to go back to Issues No. 21 and No. 22. Here I only need to note that the ELF "concealment" system causes the f3 (the 3 dB bass cutoff corner) to slide up and down the frequency scale as the power into the driver goes up and down. The frequency response of the Infrasub18 was dead flat (±0.5 dB) down to 10 Hz, the limit of my measurement capability, as long as I didn't push the 1meter SPL into the high 90s

ISSUE NO. 25 • WINTER 1998-99

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(as normalized to 40 Hz). That's flatter and deeper than anything else in the business; the Infrasub18 is unique in that respect. (The printed claim is actually an f3 of 8 Hz.) Theoretically, the resulting improvement in group delay across a significant portion of the lowfrequency band should have some audible effect, but I can't confirm that. The total subjective impact of a subwoofer depends not only on lowfrequency extension but also on distortion, damping, maximum SPL, etc., so I would need to set up

an ABX test between two Infrasub18's, a standard one and a modified one with a much higher smallsignal f3 but otherwise indentical, in order to zero in on that single sonic characteristic.

Speaking of distortion, that's not where the Infrasub18 shines. The FFT spectrum of a 20 Hz tone at a 1 meter SPL of 90 dB (into 2π steradians, i.e., out on the open floor) shows the 2nd harmonic to be at 20 dB (10.0%), the 3rd harmonic at 22 dB (7.9%), the 4th harmonic at 33.5 dB (2.1%), the rest negligible. Not very impressive, since 90 dB is a fairly modest SPL where the ELF concealment circuit does not even come into play at 20 Hz. The 30 Hz distortion at the same SPL is 23.5 dB (6.7%) 2nd harmonic, 38 dB (1.3%) 3rd harmonic, the rest negligible. Going up to 40 Hz at the same SPL, which should really be a breeze, the 2nd harmonic is still 26 dB (5.0%) and the 3rd harmonic 49 dB (0.35%). Raising the

40 Hz SPL to 97 dB, which is far from unreasonable, the 2nd harmonic rises to 22.5 dB (7.5%) and the 3rd harmonic to 42 dB (0.8%). I also took a THD sweep from

100 Hz down to 20 Hz, at a 1meter SPL of 91 dB as nor-

malized to 50 Hz. That was still below the concealment threshold as far as I could tell. The THD curve breaks sharply at 70 Hz, where the distortion is only 0.21%, and rises in an almost straight line against the logarithmic vertical scale to 13% at 20 Hz, more or less confirming the inbetween frequencies as measured in the FFT tests.

Thus, the Infrasub18 appears to be the powered subwoofer with the most extended lowfrequency response but also the highest distortion, at least among the designs known to me. Is there an audible downside to that? None that I could discern at the SPLs I am able to tolerate in my listening room. The sound of the Infrasub18 is basically as impressive as I described in my original review of the Bag End S18EC with ELF1 outboard electronics. With the simplified builtin electronics you connect your signal source to the linelevel input and your main amplifier to the highpass outputs, set the level, and you're in business. There's a polarity switch if you need it for the most seamless crossover (I did). The crossover slopes are inherently 12 dB per octave with the ELF system, and the crossover frequency is factoryset at 95 Hz on the Infrasub18. It all works very smoothly. The ease of matching the sub to the main speakers is arguably greater than with other systems. If this were the only supersub on the market, I could live with it happily forever after.

It so happens, however, that several other high performance powered subwoofers are significantly lower in distortion and have greater SPL capability per dollar. At its original introductory price, the Infrasub18 would still be a "best buy." At its current price, I would like to see better distortion figures. This journal still regards the ELF system as just another interesting and plausible engineering approach, not a breakthrough. Our Dr. David Rich had an extended dialogue with designer Ron Wickersham and ended up respectfully disagreeing with the latter that the ELF bassboost circuit is an "integrator." No matter how you slice it, it's still an equalizer. (A classic case of a rose by another name that smells as sweet.)

Bag End MM-8B Time-Align

Bag End Loudspeakers, Modular Sound Systems, Inc., P.O. Box 488, Barrington, 1L 60011. Voice: (847) 3824550. Fax: (847) 3824551. Email: info@bagend.com. Web: www.bagend.com. MM8B TimeAlign nearfield monitor, $2264.00 the pair. Tested samples on loan from manufacturer.

I have always found that the downside of coaxial driver design is much greater than the claimed advantages, undeniable as they are. The heart of this small monitor for the professional market is an 8inch woofer with a horn tweeter firing through the apex of the cone. The

1.75inch mouth of the horn is extended by the flare of the woofer cone. The transition between the two drivers is not smooth, as it hardly ever is in a coaxial configuration, and there are serious disturbances in frequency response as a result. This inherent design problem can be solved by making the woofer and tweeter both coaxial and coplanar, as in the now defunct Win SM10, which had a proprietary Japanese frame that could accommodate flat diaphragms in the same plane. No other solution really works in my experience.

The Bag End MM8B monitor incorporates Ed Long's familiar TimeAlign technique, which goes back to 1976 and is claimed to yield superior performance in the time domain. Indeed, the acoustical output of the speaker shows an unusual degree of time coherence, with the leading and trailing edges of square waves still quite well preserved after passing through the electroacoustic transducer. I attach relatively little importance to that these days, although I used to; I am convinced now that you can't hear it. "Look, Ma, no phase shift" is intellectually appealing but perceptually insignificant; David L. Clark proved conclusively in 1983 that the phase shift has to be gigantic before it becomes audible. (Except at low frequencies, but that's a horse of another écurie.) I didn't

have my head set straight on this subject until much later, and there are readers who still keep reminding me of my former allegiance to time-coherent design. Hey, I'm still not against it; like chicken soup, it can't hurt; but the

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