Signals & Noise (Letters to Editor) (Jan. 1994)

P.S. from DGX

Dear Editor:

DGX Audio would like to express our gratitude to Audio magazine for the cover spot and comprehensive review of our Digital Deconvolution Audio System (DDAS) in the November 1993 issue. Our design objective was to develop the best-sounding system and offer it at a price most people can afford. To make the best speaker--or the best of anything--always takes the experience of "shakedown cruises" and sub sequent redesign, adjustment, and fine-tuning. In his complimentary review of our new product, D. B. Keele, Jr. identifies two areas for improvement.

First, he states that the bass, although well controlled, is overemphasized. The bass roll-off compensation of the system was tuned according to the results of recent listener-preference investigations. In fact, we originally provided multiple user-select able bass roll-off compensation levels. This feature will be included on all systems delivered in the future. We appreciate that bass level is a matter of personal taste--and in this case, allowing listeners to make the choice is the perfect solution.

Second, Mr. Keele points out that the loudspeaker exhibits less than perfect vertical-coverage characteristics. We have since made crossover adjustments that dramatically widened the vertical listening window We believe that the DDAS is the best- sounding audio system available. Perfection is elusive, but with the feedback of interested and experienced associates such as Mr. Keele, we're getting ever closer.

-David Chiang and Gary Brown, DGX Audio Ronkonkoma, N.Y

"SuperRadio" Meets Super Antenna

Dear Editor:

I can fully confirm Leonard Feldman's findings-and enthusiasm-about the Denon TU-68ONAB "SuperRadio" ("Equipment Profile," April 1993). A simulcast here in Portland reveals KINK AM sounding even better than KINK FM. Most & NOISE people choose the AM when asked to pick the FM in an A/B comparison! The Denon is also by far the most sensitive and selective FM tuner I have ever used.

A postscript on the LF Engineering M 601 AM antenna Mr. Feldman suggests using with the tuner ("Auricle," July 1993):

I installed one and discovered a possible problem for urban dwellers. I live a couple of miles from two AM transmitters and seem to have cross-modulation problems across the entire AM band when the r.f. amplifier in the M-601 antenna is used. However, I find that simply not applying power to the system solves this problem- and I am getting far superior reception of local and distant AM stations by using this antenna with the r.f. amp off, compared to what I was receiving on the Denon tuner's attached loop antenna. So the LF Engineering antenna still seems worth buying and installing in any location.

Editor's Note: Your problem sounds like simple overload to me, but your simple solution works, so use it.

Always Use Your Zip Cord?

Dear Editor:

Fred E. Davis' excellent article, "Speaker Cables: Testing for Audibility" (July 1993), concludes that for average systems and short cables, differences between cables (including ordinary zip cord) are "at the threshold of audibility." This article reminds me of a talk given recently by Edgar Villchur at the 1993 banquet of the Boston Chapter of the Audio Engineering Society. Villchur was describing the "live versus recorded" concerts staged by AR in the late 1960s, at which an immediate comparison was i between live music and its reproduction through AR-3 loudspeakers. (The consensus among critics was that most of the switches were not detectable-and that when a difference was noted, one could not be certain by sound alone which source was live and which recorded.)

Of all tests, this is the most exacting, and Vilichur said: "At these concerts we couldn't afford to use auxiliary equipment that would compromise the quality of re production. And so offstage there was a professional Ampex tape recorder, two 60- watt Dynakit amplifiers, and for the 40 or 50 feet between the amplifiers and the speakers, we used #18 zip cord." The Boston AES audience had laughed at Villchur's occasional quips, but they roared at this remark.

-Roy Allison; President, RDL Acoustics Bellingham, Mass.

Don't Get Wired

Dear Editor:

I always find your articles on speaker cables interesting. As a high-end audio retailer, we rarely sell anyone their first system; we mostly, sell improvements to systems, or we sell people their second or third systems. We sell a lot of cables.

We've had all of the major brands of cables in to evaluate. Some improved the sound, some made the sound worse. When people come in and are looking to improve their system, cables are often recommended. A great many people are skeptical (understandably), so we've found it is easiest to let the customer take the cables home and try them. If they make a significant improvement to the sound, buy them. If they don't, don't buy them. It's that easy. We sell a lot of cables (and other equipment) that way. Listen for yourself! Keith Dowd Audioport Overland Park, Kans.

Another Cable on Cables...

Dear Editor:

I was so impressed with Fred E. Davis' article on speaker cables that I just signed up for a three-year subscription.

It was refreshing to read (in a consumer- oriented magazine, no less!) a scholarly article that fully explored a subject and offered conclusions based on empirical data rather than opinions only. I am not an engineer, but I want to know why equipment works and sounds the way it does, not just how it sounds. Davis did an excellent job of explaining key terms and some of the basic physics involved.

I gave up on other "stereo magazines" long ago. Your July issue showed I could gain worthwhile information after all.

...and another...

Dear Editor:

Thank you for the article on speaker cables. Fred E. Davis gets to the heart of the speaker wire controversy. Now, if you could have an article that gets to the heart of the CD jitter controversy...

-Steve Doyle; Kamuela, Hawaii

Editor's Reply: Okay, Mr. Doyle, good suggestion. We'll see what we can do.

"Unauthorized Reproduction”

Dear Editor:

For some time I have been curious about what exactly recording companies mean by "Unauthorized reproduction of this re cording is prohibited by Federal law and subject to criminal prosecution." Could you summarize what exactly I can and can't copy on tape?

Jason S. Berman, President of the Recording Industry Association of America, replies:

Matt Jurach's letter is a good one. Under U.S. copyright law, a copyright owner of a sound recording ordinarily has the exclusive right to control the reproduction and distribution of that sound recording. The copyright law imposes not only civil liability for those who infringe on a sound recording copyright owner's rights, but also criminal liability where the infringement is willful and for purposes of commercial gain. The warning described in Mr. Jurach's letter thus serves as an enhanced form of copyright notice and hopefully serves to discourage record piracy.

Of course, under the Audio Home Re cording Act enacted in October 1992, a con may make a copy of a sound recording for the consumer's own non commercial use without incurring any copyright liability. This limited exception does not, however, negate the importance and value of a broader warning against copyright infringement.

Audio Collection Available

Dear Editor:

For more than two decades I have thoroughly enjoyed Audio . It is the only magazine of its kind in the United States that I've ever subscribed to.

I now have a large collection of Audio, spanning some 25 years, that I must part with for reasons of space. Perhaps some of your readers would be interested.

Dolby S: Surviving

Dear Editor:

In the July 1993 issue, Edward J. Foster expressed regret about. the possible fate of Dolby S noise reduction in competition with DCC and MD ("Equipment Profile" of Aiwa XK-S9000 cassette deck). Well, please tell Mr. Foster that he need not shed a tear for Dolby S. Recently, some heavy hitters have stepped up to support it. The Warner/Elektra/Atlantic group has announced that all future titles will be re leased in the format. Sony now has a line of Dolby S cassette decks starting at less than $400, a significant price break.

For some reason, though, these stories have been ignored or buried by most U.S. media outlets. There seems to be a general infatuation with things digital, fed by the invalid notion that if something uses computer code it must be better. But, I'm sure you'd agree, the public needs to be disabused of such ideology, for the sake of its pocketbook if nothing else! This is true de spite the egg that the expensive digital formats have laid on the market.

One way that Audio can make an impact is to run a comparative listening test be tween Dolby 5, DCC, and MD. But unlike the Dolby S versus DAT evaluation con ducted by Stereo Review, the source should be live music (not CDs), which would make for a much more demanding test.

On another front, the Denon TU 680 NAB tuner seems to be getting a lot of (probably much-deserved) attention of late ("Equipment Profile," April 1993). How ever, the abilities of another "super radio" with superb AM stereo specs, the Carver TX-i ib, should be brought to light.

( Audio magazine, 01/1994)

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