SIGNALS & NOISE (Letters to Editor) Aug. 1985

The Bucks Keep Going

Dear Editor:

I read, with amusement, Ivan Berger's January 1985 "Spectrum" item on the quest for the most expensive stereo system possible. This is a little game that I have been playing with your Annual Equipment Directory for the last few years.

However, Mr. Berger will have to spend just a little more for his system. I believe the Wilson Audio Modular Monitors require bi-amplification, so he will need four Esoteric Audio Research 529 power amps-which will cost him $20,000. I also recall reading some where that two Mark Levinson ML-2 amps can be strapped together to pro duce 100 watts. Therefore, if he gets eight ML-2s, he can spend $27,560.

Admittedly, this reduces him to only 400 watts total power versus 2,000 watts with the E.A.R. amps, but maybe his hearing will last longer and he can enjoy his investment more.

Now the question is, can all of these goodies be plugged into the Burmester 808 preamplifier at once? Probably not. Perhaps Mr. Berger could com mission a custom switching center/ patch bay with gold-plated connectors and pure silver wiring.

-Stephen M. Smith; Shawnee Mission, Kans.

Editor's Note: You're right about the WAMMs needing bi-amplification. Strapping the Levinsons smacks, to me, of sadism. And I already have an Audiovisual Systems patch bay with gold external connectors, though not, alas, with silver internal wiring. - I. B.

Right-On Reviews

Dear Editor:

Mr. Anthony H. Cordesman should be congratulated for giving precise re views of various speakers on the market. I am referring particularly to the review of the Celestion SL-600 in the February 1985 issue, in which he states that the speakers are excellent but have certain shortcomings. It is exactly my feeling, especially when it comes to the price of the equipment and the $350 charge for the stands. I find all your reviews very informative, not like the ones found in another hi-fi magazine that never brings out the negatives. When reading your competitor's kauderwelch, one gets the feeling that they do not want to hurt a potential advertiser's feelings.

Another point of satisfaction is your complete listing of all equipment avail able, as done in your Annual Equipment Directory every October. It seems that your staff does their home work and searches the market for every piece of available hi-fi equipment, while Stereo Buyers Guide only prints what is readily available without looking for the more unusual type of equipment, well-constructed and considered by some to be the cream of the market.

Thank you for thinking about the consumer when publishing Audio, and keep up the good reporting.

-William W. Menz; Winston-Salem, N.C.

The Polls Are Now Open

Dear Editor:

Thank you for "The DNR Noise Reducer: How It Works and How to Build It" (by Leonard Feldman and R. Aryana, February issue). I've just completed my unit, and it works better than I had hoped it would. I vote yes for more construction and technical articles in your magazine.

As a collector of old blues, jazz and swing recordings, I am interested in all types of single-ended sound enhancement and noise reduction. With all the hoopla over the Compact Disc, let's not forget the thousands of priceless musical performances contained on noisy 78s, LPs, and analog tapes. Any thing science can do to rescue these old recordings is to be applauded.

How about an article on this subject soon? I'd love to learn how digital technology may someday be used to "clean up" dirty sound sources, and suspect that the record companies have already done substantial re search in this area.

In the meantime, I hope you keep up the good work.

-Dennis Mosher; Brea, Cal.

Here Kitty, Kitty

Dear Editor:

With regard to Ivan Berger's item "Live End, Cat End" in February's "Spectrum": As Plinius the Elder wrote in one of his famous books, De felibus, his problem with cats is, "Feles dicto non auditem est!" Or, you cannot tell a cat a damned thing. Having gone through 25 cats in 25 years, I agree with Plinius.

There are three remedies pre scribed: You can either kill the cats, ban them from the music room, or de-claw the front paws.

Again following Plinius, "Felem potius quam hominem amo," I chose the third remedy. My cats have now be come indoor gentlemen, but, malgre tout, still try to scratch everything.

However, now they can merely wipe their paws, which is a bit easier to cope with.

However, I found that a greater problem is cat hair. They, the hairs, float through the air and then race onto the shiny surfaces of the 12-inch LPs or the 4-inch CDs with equally deleterious effect. The use of fluids is the only remedy for that, in a place where the humidity approaches zero in summer.

"kat ov TEKVOV," said Caesar when Marcus Brutus stabbed him to death, or, as they used to say in old India, "tat tvan asi!"

-Paul A. Elias; Fountain Hills, Ariz.

Blazing Players

Dear Editor:

Now that Pioneer has their CLD-900 Compact Disc/Laserdisc player (pro filed in the February 1985 issue), the future of the marriage between audio and video looks very bright. In fact, with upcoming versions of such players, we may see the following features:

The ability to read the CD subcode that will soon contain text and graphics data (liner notes, librettos, song lyrics, scenes from operas, etc.) without having to resort to an external converter if such information is shown on a TV screen.

The ability to see on the TV screen what you have actually programmed into the CD or videodisc player (like what the CLD-900 and some video recorders do, only more advanced).

The ability to use all four channels of audio sound (two digital, two AFM) simultaneously to produce fabulous-sounding motion pictures, using the digital channels for front sound and the AFM channels for rear ambience sound. With the help of the Studer/Revox digital signal processor, imagine a George Lucas film done by this method! You'd swear that the battle scenes from Star Wars have been moved into your living room. Imagine, movie sound better than a theater's! In short, thank you, Pioneer. You have blazed the way for the ultimate in home entertainment.

-Raymond Chuang; Sacramento, Cal.

Remember When?

Dear Editor:

A well-deserved thanks is in order to Audio for taking the editorial space, in the March issue, to explore in detail the problems facing FM today. The willingness of the magazine to bring to its readers greater knowledge, and the ability to do so accurately, makes Audio the pre-eminent journal of its kind.

As a veteran broadcaster (who also started at WYBC), I unfortunately have to agree that audio chains have corrupted a superlative medium. Many hours have been spent cajoling engineers to "back off on the compression," only to have program directors and general managers ask why we're not loud enough. Some say all of this started in the AM Top 40 wars when loudness was critical, then carried over to FM when it became financially equal to AM (and equally competitive). At this point, after replacing AM as the music carrier, it is likely that FM is the worst medium for reproducing music that most people are regularly exposed to.

The main problem is no longer technology, but a consistent underestimation of the audience's ability to perceive and appreciate uncolored mu sic. This really amazes me. When it comes to rock, my field, the producers have already removed most of the dynamics and have boosted certain frequencies in anticipation that the piece will be heard on an original Marconi wireless. To further process this signal is simply adding saccharin to Nutra-Sweet. Overkill is too tame a word here. Of course, I've had calls from listeners who have no idea what stereo is-and couldn't care less-but that hasn't stopped them from asking why the record they bought sounds infinitely better than the same one we're playing. (We've all heard the rim shot with a sustain that's louder than its attack, thanks to hyper-fast limiters that grab and release the dynamic.) The good news is that the solution is right here, in every broadcast studio. These same high-tech compressor/limiters can be used to make FM not only better than it is now, but, theoretically, nearly as open as a Compact Disc. If the NAB could agree on a format (a major hurdle), we could use our audio chains as the first leg of a two-ended, compansion noise-reduction/dynamic range expansion system. By setting up the compression at the broadcast end to, say, one of three predetermined levels, the listener, if so inclined, could purchase an expander that would do the same in reverse, but accurately.

This way, those with inexpensive equipment or car units in noisy environments would continue to listen to it "loud," while those who really care about signal purity could decompress and restore the natural dynamics. The broadcasters would still be able to choose between hard, medium, or soft compression. This would go a long way towards making FM the medium it was intended to be, while not radically upsetting the status quo.

Of course, getting two stations--let alone 8,000--to agree on anything could be this proposal's undoing. But the alternative, as prerecorded music gets better and better, is losing our audience to listener fatigue.

In the meantime, call your stations and complain. One negative comment is worth a dozen positive ones. Let them know you can tell the difference between a Compact Disc and a 78, as it were. And if you happen to speak to a program director, remind him why the listeners flocked to FM in the first place: Because, at one point, it sounded better.

-Paul Rotello; Hartford, Conn.

Take Your Pick

Dear Editor:

In response to your excellent March issue focusing on FM quality, I would like to point out that, theoretically at least, there is a way to satisfy both the audiophile and the general listener.

The dominant form of FM processing is compression, similar to the encode function of a tape noise-reduction unit.

An audiophile equipped with the complementary expander would not only be able to get the original signal back, but could better the unprocessed channel's dynamic range.

While there is little likelihood that broadcasters would be willing to completely standardize their processing (then everyone would sound the same . . . just like the records), an optimized 2:1 compression, perhaps along the lines of CBS's CX, could be agreed upon as a baseline for processing. The loud stations could process on top of this to get their sound. The audiophile could completely recover the signal from the more moderate stations, and an improved version from the others.

The signal could be left compressed for playback in situations where quality is noncritical.

While it is true that noncommercial radio stations do not have the short term pressure to have a punchy signal, their long-term success depends upon at least the perception of good sound quality (programming has something to do with it, too). To the listener a few miles out, the compressed signal may very well sound better.

-John H. Roberts, Phoenix Systems Stone Mountain, Ga.

Revised Ruling

Dear Editor:

I greatly enjoyed reading the articles in the March issue dealing with FM transmission fidelity. You may be interested to know that since those articles appeared, the FCC has deregulated the annual equipment performance tests and has done away with most of the technical standards governing transmission quality for AM, FM and TV (aural) stations. As regards FM specifically, the FCC requires an annual showing of compliance with the pre-emphasis curve only; this was kept to ensure receiver compatibility. Measurements and standards for distortion, separation, noise, and crosstalk were eliminated. Incidentally, the required noise figure for FM stereo transmission was -60 dB per channel, referenced to 100% modulation of audio plus pilot, not the -58 dB alluded to in the article.

A recommendation I would have for FM station engineers is one that any audiophile would also have: Keep it simple! It is a truism in the broadcasting business--where Murphy's law-of-ten--supersedes Ohm's, Kirchoff's, or any other--that the cleanest-sounding stations are often those in small markets. These stations cannot afford all the bells and whistles that the stations in the larger markets feel they must have in order to remain competitive.

The small station usually makes do with one carefully selected processor in the line. Audiophiles already know that straight-wire design yields the cleanest audio, and this is equally true in broadcasting. One small station, where I was on staff as the chief engineer, easily measured less than 0.5% THD, complied with the pre-emphasis curve within ± 0.5 dB, and had separation measured at 38 dB at 50 Hz, 50 dB at 1 kHz, and 46 dB at 15 kHz. Noise figures were -63 dB in mono and-62 dB per channel in stereo. All this was done with a single processor and no composite clipper, yet we were as loud as anyone else on the dial, and regularly received compliments on how clean our audio was.

As was pointed out, enough stations like this would revolutionize FM broad casting quality. It's worth a try, no?

-Sidney C. Schweiger; Chief Engineer; WKOX(AM)-WVBF(FM), Framingham, Mass.

More on Zero Distortion

Dear Editor.

The article "The Perfect Amp: Zero Distortion," which appeared in your April issue, contains an error. Mr. Dajan is under the impression that zero-distortion amplifiers are a new phenomenon. He should check the Annual Equipment Directory in Audio's October 1976 issue. The Bazoom 2000 manufactured by Rabid Audiophile boasts not only zero distortion but a frequency response of d.c. to light at 1,900 horsepower! Truly a remarkable piece of hardware.

-Mike Miller; Bethel, Conn.

Pyramid Power

Dear Editor:

As a new subscriber to Audio, I eagerly awaited the arrival of my first is sue. In mid-March, my mailbox was blessed with a striking magazine cover, boldly displaying that Audio had discovered the perfect amp. I quickly turned to the designated page, and found that not only was the world safe from distortion, but that the real purpose of the pyramids had been discovered. I quickly telephoned my friends; they told me I should have my head and eyes examined. "No," I replied, "Professor I. Lirpa says it works!" However, after examining the article(s) a second time, I realized my mistake. I certainly sounded foolish telling my audiophile friends who Prof. Lirpa really is.

For some reason, I think I'm going to enjoy this coming year's reading.

I.M.D. Cved; Ames, Iowa

Erratum

In the June 1985 "Roadsigns" column, we mistakenly described the power jack on Parasound's CDS-1 in put-switcher box, which allows connection of a portable CD player to a car stereo system. The jack's output is 9 V d.c.

(Source: Audio magazine, Aug. 1985)

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