In Reply to: Link for the above posted by Bibo01 on April 29, 2012 at 17:22:26:
Why does a difference in the digital file that's bounded at -138.47 dB below 0 dBfs manage to affect a graph around -100 dB?
Perhaps I misread or misunderstood the graph, but I believe this is the nub of the issue. I doubt seriously that people can hear changes in noise that is -139 below peak levels, but I know from personal experience that I can just barely hear sound that's at -97 dB below 0 dB FS, and that's using monitor gain settings that I actually use for one or two recordings in my library (both Mahler symphonies). For solo harpsichord recordings the monitor gain would be turned down another 15 dB and this noise would be inaudible to me in my room.
I suspect some artifact of the DAC is magnifying the small difference and turning it into slightly different noise. (Technically, this is called noise modulation.) If my suspicion is correct, this is a serious indictment of the DACs in question, including mine (as I heard a difference). This calls for a new test of DAC performance.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
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Follow Ups
- RE: Link for the above - Tony Lauck 11:21:02 04/30/12 (5)
- RE: Link for the above - Bibo01 00:59:19 05/10/12 (4)
- Null Test Differences (NTD) are problematic - Tony Lauck 08:40:43 05/10/12 (3)
- RE: Null Test Differences (NTD) are problematic - Bibo01 15:15:42 05/10/12 (2)
- RE: Null Test Differences (NTD) are problematic - Tony Lauck 15:28:30 05/10/12 (1)
- RE: Null Test Differences (NTD) are problematic - Bibo01 15:39:58 05/10/12 (0)