"The large peak at 16kHz reported by Stereophile...was nowhere in evidence...The most probable explanation of this discrepancy is that the [Waveform supertweeter's] very light ribbon depends on the air load for damping, and that load is much smaller in the thin air up there at 7000' in Santa Fe than at altitudes where less lightheaded and scientifically more accountable reviewers dwell." Thus spake Peter Aczel (footnote 1), erstwhile loudspeaker designer and Editor/Publisher of the reincarnated The Audio Critic, a publication that advertises itself as having "unusual credibility among the top professionals in audio."
The promise of "perfect sound forever," successfully foisted on an unwitting public by the Compact Disc's promoters, at first seemed to put an end to the audiophile's inexorable need to tweak a playback system's front end at the point of information retrieval. Several factors contributed to the demise of tweaking during the period when CD players began replacing turntables as the primary front-end signal source. First, the binary nature (ones and zeros) of digital audio would apparently preclude variations in playback sound quality due to imperfections in the recording medium. Second, if CD's sound was indeed "perfect," how could digital tweaking improve on perfection? Finally, CD players and discs presented an enigma to audiophiles accustomed to the more easily understood concept of a stylus wiggling in a phonograph groove. These conditions created a climate in which it was assumed that nothing in the optical and mechanical systems of a CD player could affect digital playback's musicality.
When sociologists tell us America is a highly mobile society, they don't just mean we do lot of driving. What they mean is, we do a lot of moving. The good old three-generation family homestead, immortalized in nostalgia TV and literature, is a thing of the past. According to census information, almost 20% of America's population changes its address every year. Of course, it's usually a different 20% every year, but pulling up roots and moving---to a bigger house, a better neighborhood or a nicer city, not to mention a place where your employer decides to transfer you---is almost as commonplace across the US of A as marriage, divorce, and unbridled greed.
Wouldn't you just know it. As soon as I decide on a formal regime of measurements to accompany Stereophile's loudspeaker reviews—see Vol.12 No.10, October 1989, p.166—along comes some hot new technology that changes everything. Robert Harley reported in last month's "Industry Update" column how impressed he and I were with the new MLSSA measurement system from DRA Laboratories.
"My system has great imaging!" "I can hear sound coming from beyond my speakers." "The depth image in my system goes back at least 20 feet." Yes, we audiophiles are proud of our imaging (footnote 1), and we've worked hard to get it. My back is still aching from the last time I tweaked my speakers until the image was just right.
It is always a matter of great interest when a difficult question, in this case the audibility of differences between amplifiers, is put to an empirical test. When the question is tested by such intelligent, knowledgeable, and unbiased investigators as John Atkinson and Will Hammond (see the July issue of Stereophile, Vol.12 No.7, p.5, the interest is even greater. Unfortunately, when the test turns out to have been flawed by errors in design and in use of statistics, as was the case here, the disappointment is also even greater.
There was a time, as recently as 40 years ago, when frequencies below 100Hz were considered extreme lows, and reproduction below 50Hz was about as common as the unicorn. From our present technological perch, it's too easy to smirk condescendingly at such primitive conditions. But just so you're able to sympathize with the plight of these disadvantaged audiophiles, I should tell you that there were two perfectly good reasons for this parlous state of affairs. First of all, program material at that time was devoid of deep bass; not because it was removed during disc mastering but simply because there wasn't any to begin with. The professional tape recorders of the day featured a frequency response of 5015kHz, ±2dBjust about on a par with the frequency performance capability of a cheap 1988 cassette tape deck.
Like many Stereophile readers, I have often sped home from a concert to fire up the audio system and then, to the sore vexation of my wife and guests, spent the rest of the evening plunged in the morbid contemplation of what, exactly, was missing.
When I decided to write a piece on the subject of concert-hall acoustics, I realized that almost all discussion concerning this topic is based on the viewpoint of the listener in the audience. While this is important (since the primary purpose of any hall is to bring audience and performance together), the criteria that musicians employ in concert-hall evaluation address sonic parameters that are probably not obvious to the casual listener, and may often be at odds with conclusions reached from the other side of the footlights. Some readers might feel that any discussion of concert halls has no place in a publication such as Stereophile; they may have a point, especially if their sole aim through audio is to produce sonic spectacle, rather than to recreate an artistic event. I believe, however, that there are some readers who would like to gain some insights into the specific problems and acoustical considerations presented to performing musicians, and possibly come away with some fresh ideas to incorporate in their listening criteria.
The Question of Bass: J. Gordon Holt A few issues back, in Vol.9 No.3, I used "As We See It" to clarify what Stereophile writers have in mind when they use the term "transparency" in equipment reports. This time, I'll do the same thing for the performance parameters of bass reproduction.
It has become accepted lore in audiophile circles that the 44.1kHz sampling rate adopted for Compact Disc is too low. Some writers have argued that, as a 20kHz sinewave will only be sampled about twice per cycle, it will not be reconstructed accurately, if at all.