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By contrast, Fig.25 shows a similar measurement for a loudspeaker that a Stereophile blind listening panel thought sounded quite colored, with a skewed presentation of instrumental timbres. The speaker is quite flat in the midrange and has reasonably good bass extension. However, there is a severe suckout in the mid-treble. In all but large rooms, this will produce a characteristic, hollow-sounding coloration. There's some peakiness in the mid-treble region above the suckout that will add a little bit of "zing" to the perceived balance. The designer presumably was trying to compensate for…
It's also apparent that a speaker with a basically smooth, flat response but a single area of unevenness—due perhaps to a strong woofer-cone breakup mode or a cabinet resonance—will be downgraded accordingly. The same holds true for crossover or drive-unit integration problems. Similarly, if a speaker has a flat response but limited high-frequency dispersion, its appeal will be limited due to the room reverberant field tending to sound too lifeless. And no matter how flat a speaker's midband, a somewhat loose, underdamped bass is an almost unforgivable fault for many listeners, except when…
Nearfield Responses
Because the time data need to be truncated to eliminate room reflections, a farfield MLS-derived amplitude response is of little use in characterizing a loudspeaker's behavior at low frequencies. However, a classic 1974 paper by Don Keele [64] discusses the technique of taking a loudspeaker's response in the nearfield, with the microphone capsule placed very close to the radiating diaphragm. This appears to give a response that accurately reflects a loudspeaker's low-frequency output as assessed in the farfield, a conclusion more recently confirmed by Struck and…
Because the time data need to be truncated to eliminate room reflections, a farfield MLS-derived amplitude response is of little use in characterizing a loudspeaker's behavior at low frequencies. However, a classic 1974 paper by Don Keele [64] discusses the technique of taking a loudspeaker's response in the nearfield, with the microphone capsule placed very close to the radiating diaphragm. This appears to give a response that accurately reflects a loudspeaker's low-frequency output as assessed in the farfield, a conclusion more recently confirmed by Struck and…
Polar Response/Dispersion
Looking at the anechoic response at one point in space can be instructional, but it must not be forgotten that loudspeakers emit sound in a full sphere [67]. I examine how a loudspeaker's amplitude response changes in two planes, vertical and horizontal, using the DRA Labs system's ability to plot an arbitrary number of FFT-derived response plots against a third, arbitrary variable [68]. The loudspeaker is rotated on a commercial stepper motor-driven turntable (made by the Italian company Outline and available from Old Colony Sound Lab) in 5 degree steps, an…
Looking at the anechoic response at one point in space can be instructional, but it must not be forgotten that loudspeakers emit sound in a full sphere [67]. I examine how a loudspeaker's amplitude response changes in two planes, vertical and horizontal, using the DRA Labs system's ability to plot an arbitrary number of FFT-derived response plots against a third, arbitrary variable [68]. The loudspeaker is rotated on a commercial stepper motor-driven turntable (made by the Italian company Outline and available from Old Colony Sound Lab) in 5 degree steps, an…
In-Room Amplitude Response
Unlike other audio components, the perceived sound of a loudspeaker is affected by factors other than its intrinsic performance. All the previous measured acoustic parameters that have been discussed examine the loudspeaker in isolation. But loudspeakers are used in reverberant rooms rather than anechoic chambers, and the interaction between the two is complicated [69, 70, 71, 72, 73, 74]. However, my experience has been that different models of loudspeakers sound different in a consistent manner when similarly set-up and auditioned in different rooms. But it…
Unlike other audio components, the perceived sound of a loudspeaker is affected by factors other than its intrinsic performance. All the previous measured acoustic parameters that have been discussed examine the loudspeaker in isolation. But loudspeakers are used in reverberant rooms rather than anechoic chambers, and the interaction between the two is complicated [69, 70, 71, 72, 73, 74]. However, my experience has been that different models of loudspeakers sound different in a consistent manner when similarly set-up and auditioned in different rooms. But it…
What Makes a Good-Sounding Loudspeaker?
Vance Dickason [77] offers some discussion of this question, but the definitive answers are to be found in Floyd Toole's comprehensive 1986 papers [78, 79]. Nothing that I can conclude from my past eight years' work, at least when it comes to conventional forward-firing, moving-coil designs, is in serious conflict with his findings. As I wrote in 1991 [80], "The best-sounding loudspeakers, in my opinion, combine a flat on-axis midrange and treble with an absence of resonant colorations, a well-controlled high-frequency dispersion, excellent…
Vance Dickason [77] offers some discussion of this question, but the definitive answers are to be found in Floyd Toole's comprehensive 1986 papers [78, 79]. Nothing that I can conclude from my past eight years' work, at least when it comes to conventional forward-firing, moving-coil designs, is in serious conflict with his findings. As I wrote in 1991 [80], "The best-sounding loudspeakers, in my opinion, combine a flat on-axis midrange and treble with an absence of resonant colorations, a well-controlled high-frequency dispersion, excellent…
REFERENCES
[52] D.D. Rife, "Loudspeaker 'Anechoic' Response," DRA Labs MLSSA Reference Manual v.10.0A, pp.153-158 (1996).
[53] "Types 4003 & 4006 Specifications," Series 4000 Professional Microphones User's Manual (Brüel & Kjaer 1989).
[54] M. Colloms, High Performance Loudspeakers, Fourth Edition, pp.147-151 (John Wiley & Sons, 1991).
[55] G. Sanders, "Manufacturer's Comment: Martin-Logan," Stereophile Vol.20 No.5, p.225 (1997 May).
[56] J.G. Holt, "Down With Flat!" Stereophile Vol.8 No.4, pp.5-8 (1985 August).
[57] M. Colloms, High…
Hasil Adkins: Out to Hunch
Norton Records (no catalog # whatso-a-ever) LP, no CD. No producer, no engineer, no studio, no stereo, no mikes that weren't carbon police dispatcher models, no other people at all in fact—just Hasil Adkins, vocals and guitars and one-man drums and some weird rhythmic screeching that may or may not be LP surface noise. TT: infinite, as I can't stop hearing it in my head hours after I raised the needle off it.
To order, send $10 to Norton Records, Box 646, Cooper Station, New York, NY 10003. If you don't, you shall burn in hellfire eternal. Hasil Adkins Fan…
Norton Records (no catalog # whatso-a-ever) LP, no CD. No producer, no engineer, no studio, no stereo, no mikes that weren't carbon police dispatcher models, no other people at all in fact—just Hasil Adkins, vocals and guitars and one-man drums and some weird rhythmic screeching that may or may not be LP surface noise. TT: infinite, as I can't stop hearing it in my head hours after I raised the needle off it.
To order, send $10 to Norton Records, Box 646, Cooper Station, New York, NY 10003. If you don't, you shall burn in hellfire eternal. Hasil Adkins Fan…
Charles Hansen said it best, in a recent e-mail: "People have been holding back from criticizing this technology because they weren't certain that some new discovery hadn't been made." Ayre Acoustics' main man was talking about "upsampling," whereby conventional "Red Book" CD data, sampled at 44.1kHz, are converted to a datastream with a higher sample rate. (Because of its association with DVD-Audio, 96kHz is often chosen as the new rate.)
I first heard this at HI-FI '98 in Los Angeles, where Steven Lee of Canorus, the then distributor of Nagra and dCS, was using a professional dCS 972…
Letters on upsampling were published in the March 2001 Stereophile:
Bob Katz on upsampling
Editor: In January of the first year of the third millennium, John Atkinson reviewed some new DVD-As that had been originally recorded at 44.1 or 48kHz and then upsampled to 88.2 or 96kHz, and stated that there would be no potential advantage to doing that. Actually, there is significant sonic advantage to remastering and reissuing entire catalogs that were originally recorded at 16-bit/44.1kHz.
Here's a summary of why even those recordings that do not contain high-frequency…