Prior art
Interest in Doppler distortion began in 1943, with the publication of a paper by two RCA engineers, G.L. Beers and H. Belar, which was the first to identify and quantify this distortion mechanism (footnote 1). Interest in the subjective effects of Doppler distortion intensified in the 1960s with the work of James Moir in the UK (footnote 2) and Paul Klipsch in the US (footnote 3), both of whom concluded that it had a significant effect on speaker sound. But these findings relied in major part on comparisons of speakers with different levels of Doppler distortion, the…
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Even when this degree of care is taken over interpolation accuracy and filtering, there remains the possibility that some subtle signal degradation will occur, not least because of the addition of TPDF (Triangular Probability Density Function) dither, prior to requantizing the processed signal, raises the noise floor. To account for this, I included in the software a "Generate Reference" option, which applies the same processing steps without the addition of frequency modulation, and generates all output samples from points midway between interpolated samples to ensure that the maximum…
Sidebar: Doppler and DiAural
Although the initial fuss that accompanied Ray Kimber's 1999 launch of DiAural—the proprietary speaker-crossover technology developed by Eric Alexander—has died down, the fact remains that it was and still is promoted as a means of canceling the Doppler distortion introduced by microphones: "Doppler Decoding," in DiAuralspeak. To my knowledge, however, this claim has never been challenged in the audio press. Although DiAural's two patents (US 6,115,475 and 6,310,959 B1, copies of which you can download from the US Patent Office make no mention of Doppler…
Keith Howard returned to DiAural in January 2005 (Vol.28 No.1):
When I wrote the "Doppler and DiAural" sidebar for my recent feature about Doppler distortion in loudspeakers ("Red Shift," November 2004, p.67), I fully expected a retort from DiAural founder Ray Kimber, of Kimber Kable. In the event, both he and Eric Alexander, the originator of DiAural's crossover design concept, took up their pens to point out to me that the Doppler decoding explanation with which DiAural was launched had been withdrawn before my article was published.
I wish, of course, that I had known this…
For months now, I've been beating the drum for full-range center-channel speakers, to reproduce recordings with a true center-channel signal. There are many reasons for this.
First, if you have a refrigerator-sized, big-screen TV in the middle, there's no way your main L/R pair can create decent centerfill without help (and even then, don't expect much).
Second, even without that monster in the middle, redistributing the center channel to the left and right speakers will, of necessity, introduce phase problems that can't be corrected with level adjustments or speaker…
Sidebar: Recordings In the Round: RCA Living Stereo on SACD
Three-Channel SACD/Two-Channel SACD/Two-Channel CD
A HI-FI SPECTACULAR
SAINT-SAËNS: Symphony 3, "Organ"
DEBUSSY: La Mer
IBERT: Escales
Charles Munch, Boston Symphony Orchestra
BMG Classics 8287-661387
TCHAIKOVSKY: Piano Concerto 1
RACHMANINOFF: Piano Concerto 2*
Van Cliburn, piano; Kiril Kondrashin, RCA Symphony Orchestra; Fritz Reiner, Chicago Symphony Orchestra*
BMG Classics 8287-661392
MUSSORGSKY: Pictures at an Exhibition, Night On Bald Mountain
Fritz Reiner,…
In my January "The Fifth Element" column, I discussed the concept of value in the context of audio component manufacture. This month's "Letters" includes a response to that column from Austrian distributor Hans Hirner. In his letter, Herr Hirner writes about some of his Web-surfing non-customers: "If that weren't enough, they also call me or my dealers to tell them how proud they are, after having taken all from me that is possible in system matching and trial—and even denoising their systems—to have been able to find 'our' products cheaper out there."
The phenomenon Hans Hirner…
The letter that triggered the column, from March 2002 (Vol.25 No.3):
Sensible shopping?
Editor: John Marks was so right, in "The Fifth Element" in January (pp.55-59), that there is a lot of unfair competition out there. As a small distributor of pro and home audio products in "little" Austria, I have more than once had to feel that kind of storm. I adhere to a philosophy of strict and absolute service to the customer: Never in eight years have I taken one schilling for any repair or service for products distributed by me; everybody is offered free listening in his own system (…
John Atkinson sets the stage
Nothing seems to polarize people as much as the vexed question concerning the importance of audible differences between amplifiers. If you think there are subjective differences, you're an audiophile; if you don't, you're not. And as any glance at an appropriate issue of Consumer Reports—the publication for non-audiophiles—will confirm, the established wisdom is that once the price of an amplifier or receiver crosses a certain threshold, any further improvement in sound quality becomes irrelevant, in that it puts the price up for no apparent gain. In other…
Nothing seems to polarize people as much as the vexed question concerning the importance of audible differences between amplifiers. If you think there are subjective differences, you're an audiophile; if you don't, you're not. And as any glance at an appropriate issue of Consumer Reports—the publication for non-audiophiles—will confirm, the established wisdom is that once the price of an amplifier or receiver crosses a certain threshold, any further improvement in sound quality becomes irrelevant, in that it puts the price up for no apparent gain. In other…
System & Methodology
As suggested in one of this month's "Letters," I had actually considered restaging the 1985 "Carver Challenge," where a Carver M1.0t could be compared with a pair of Conrad-Johnson Premier Fives. In the event, however, I decided that as Stereophile had just bought a recent Adcom GFA-555 to compare with an early sample (footnote 3), it would be one of the test amplifiers. (The $750 '555 has always been a safe Class C recommendation in Stereophile's "Recommended Components.") The other amplifier, as different in design as possible, would be the similarly powerful…
As suggested in one of this month's "Letters," I had actually considered restaging the 1985 "Carver Challenge," where a Carver M1.0t could be compared with a pair of Conrad-Johnson Premier Fives. In the event, however, I decided that as Stereophile had just bought a recent Adcom GFA-555 to compare with an early sample (footnote 3), it would be one of the test amplifiers. (The $750 '555 has always been a safe Class C recommendation in Stereophile's "Recommended Components.") The other amplifier, as different in design as possible, would be the similarly powerful…