Double-blind test of SACD and DVD-A vs. Redbook 16/44 in JAES Septembe, (hint: no surprises!) (bumped from 2007 in post #35) Options

[Axon]

"Audibility of a CD-Standard A/D/A Loop Inserted into High-Resolution Audio Playback". E. Brad Meyer and David R. Moran. JAES 55(9) September 2007. It's worth noting that members of the BAS wrote the paper and performed in the tests. You'll need an AES membership to access the article, so no link.

Abstract:

Claims both published and anecdotal are regularly made for audibly superior sound quality for two-channel audio encoded with longer word lengths and/or at higher sampling rates than the 16-bit/44.1-kHz CD standard. The authors report on a series of double-blind tests comparing the analog output of high-resolution players playing high-resolution recordings with the same signal passed through a 16-bit/44.1-kHz "bottleneck." The tests were conducted for over a year using different systems and a variety of subjects. The systems included expensive professional monitors and one high-end system with electrostatic loudspeakers and expensive components and cables. The subjects included professional recording engineers, students in a university recording program, and dedicated audiophiles. The test results show that the CD-quality A/D/A loop was undetectable at normal-to-loud listening levels, by any of the subjects, on any of the playback systems. The noise of the CD-quality loop was audible only at very elevated levels.

This post has been edited by Axon: Sep 10 2007, 04:13

[DonP]

One argument I would consider is that if any component in the chain wouldn't pass the higher frequencies of the hirez signal, then THAT would prevent the very golden eared from ABXing the difference. Getting good dispersion even up to 20 kHz is a notorious weak point for most speakers.

Playing the music at borderline painful levels may be ok for validating the noise floor, but I'd think triggering the ear's internal AGC (tensing up the ear bones) could reduce high frequency hearing (in the moment; not referring to the permanent damage it does.)

This post has been edited by DonP: Dec 20 2012, 14:27

[sawdin]

If the BAS testing was so flawed, why haven't those who vociferously disagreed with the stated results stage 'better designed/implemented' ABX tests? If they have, please provide links. If they haven't, why not; Is it a question of expense and/or logistical concerns?

[Arnold B. Kruege...]

If the BAS testing was so flawed, why haven't those who vociferously disagreed with the stated results stage 'better designed/implemented' ABX tests? If they have, please provide links. If they haven't, why not; Is it a question of expense and/or logistical concerns?

Most critics of Meyers and Moran also seem to have problems with ABX testing all by itself. After all, it tends to not reinforce their prejudices! ;-)

The first thing that most golden ears do when trying to replicate tests with results they disagree with is *improve* on ABX. The results are usually pretty funny (in a dark way) once the dust settles. Example that comes to mind: John Atkinson testing power amps for Stereophile with his own DBT procedure.

This post has been edited by Arnold B. Krueger: Jan 7 2013, 15:51

[drmoran@aol.com]

If the BAS testing was so flawed, why haven't those who vociferously disagreed with the stated results stage 'better designed/implemented' ABX tests? If they have, please provide links. If they haven't, why not; Is it a question of expense and/or logistical concerns?

Most critics of Meyers and Moran also seem to have problems with ABX testing all by itself. After all, it tends to not reinforce their prejudices! ;-)

The first thing that most golden ears do when trying to replicate tests with results they disagree with is *improve* on ABX. The results are usually pretty funny (in a dark way) once the dust settles. Example that comes to mind: John Atkinson testing power amps for Stereophile with his own DBT procedure.

+++

Have not been here for a long while, but I hasten to add (in response to assertions elsewhere) that Bob Stuart was not one of the auditioners (that would've been awesome, since it was his AESJ article bogoclaims which prompted the test in the first place; if I won a big lottery I would have all sorts of trip-paid challenges to tweakos). And second, we were not 'misled' by hi-rez manufacturers, at least not directly; we simply invited all listeners to bring their own favorite hi-rez material, which we listed, and much of it was Chesky direct, and not ever remasters of old stuff. Anyone who wants to redo our work should use lots of SACD and beyond, ultrahi-rez stuff, to see if that gets debunked too (whaddaya bet?). Our point was to be ample and capacious enough in all respects to give every chance for listeners to prove they could hear the RBCD bottleneck when switched in blindly. This led to a certain amount of suboptimal statistical hygiene. As a trained statistician and Journal reviewer put it, 'Given that your test was designed to allow participants every opportunity to demonstrate their ability to discriminate between A and B, you were more concerned that you not get a false positive conclusion than that there not be a possibility of reaching a false negative conclusion.'