In Reply to: Boston Audio Society Strikes Again! posted by Charles Hansen on September 11, 2007 at 09:44:35:
Mr. Hansen;
I respectfully suggest that you and anyone else who cares to comment on our paper actually read it first.
We sought diligently for source material, playback systems, and/or subjects to turn up any audible difference between the SACD or DVD-A source and the same signal passed through a CD-quality "bottleneck". We established a reference system gain (with digital full scale at about 100 dB SPL) for which we reported our results. If we increased the gain of the system by 15 dB, and used one particular recording with an extremely low background noise level (a list of sources is being prepared and will be made available to anyone who wants it), and looped the player through a bit of room tone, then anyone could hear the noise introduced by the CD codec. Played back at that level, the rest of the recording was quite a bit louder than life, since the small ensemble never reached anything close to 115 dB in the hall. This is all in the paper too.
But that (and the extreme case, when the player was stopped and the gain was up) was the only time we or anyone else could hear the difference. We did an evening of tests on a system with audiophile credentials -- recent Quad ESLs, Conrad Johnson preamp, commensurate player and power amps, $600 cables -- in a purpose built room that was very quiet and did not degrade the excellent imaging of the Quads. We used the favorite discs and cuts of the owner and his audiophile friends and let them sit and listen any way they wanted. Still no correlation. Their recordings were all noisier than the CD link, as are 99.9% of all discs out there.
The above high-gain test was done first with an inexpensive Pioneer player, which was plenty quiet enough to reveal the difference; the test exposed a small but audible low-level nonlinearity in its left channel decoder. We tried a $2000 Sony player, which sounded clean, and wound up doing the great majority of our tests with a Yamaha DVD-1500.
We also wrote that our recordings were as a class the best-sounding commercial efforts we had heard anywhere. As it happens, virtually all could have been released on a CD (just the two-channel versions, obviously) without sounding different. Why that doesn't happen is another very interesting discussion, and is addressed briefly in the paper.
-- E. Brad Meyer
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Follow Ups
- RE: Boston Audio Society Strikes Again! - EBradMeyer 09/20/0708:13:29 09/20/07 (23)
- RE: Boston Audio Society Strikes Again! - High-end Dreamer 07:29:42 10/2/07 (1)
- P.S. - High-end Dreamer 07:31:03 10/2/07 (0)
- That clears up a lot! - bjh 14:26:43 09/21/07 (14)
- RE: That clears up a lot! - EBradMeyer 20:37:38 09/21/07 (13)
- RE: That clears up a lot! - morricab 01:51:48 09/24/07 (1)
- RE: That clears up a lot! - EBradMeyer 13:31:28 09/24/07 (0)
- RE: That clears up a lot! - bjh 22:08:32 09/21/07 (10)
- RE: That clears up a lot! - EBradMeyer 05:08:50 09/22/07 (9)
- RE: That clears up a lot! - morricab 02:10:30 09/24/07 (0)
- I wrote that quote, so I feel like responding... - Axon 19:56:13 09/22/07 (5)
- You seem to have missed the crux of the objections. - clarkjohnsen 11:42:17 09/23/07 (0)
- Hmm - Ted Smith 22:29:34 09/22/07 (1)
- "Reading the [other] paper was a breath of fresh air." No kidding. - clarkjohnsen 11:54:16 09/23/07 (0)
- The scientific standard for validation of results obtained by experimental procedure is Replication. - bjh 22:27:51 09/22/07 (1)
- RE: The scientific standard for validation of results obtained by experimental procedure is Replication. - morricab 02:15:22 09/24/07 (0)
- Never mind. - tlyyra 14:19:24 09/22/07 (1)
- RE: That clears up a lot! - EBradMeyer 06:06:47 09/23/07 (0)
- What a pity. What a ditty. - tlyyra 16:07:29 09/20/07 (5)
- RE: What a pity. What a ditty. - EBradMeyer 06:25:34 09/21/07 (4)
- RE: What a pity. What a ditty. - tlyyra 08:51:16 09/21/07 (3)
- RE: That clears up a lot! - EBradMeyer 21:02:43 09/21/07 (0)
- ROFL - Pat D 12:13:00 09/21/07 (1)
- That's the way to go if you have no arguments. - tlyyra 15:00:52 09/22/07 (0)