seanadams;400678 Wrote: > I'm still wondering why you're not getting higher correlation at high > volume. It suggests to me some limiting factor, maybe some clipping or > distortion at high volume, that is masking the effect until you get down > to lower volume levels. In my tests the decrease in correlation was > exactly equal to the decrease in volume. I can't explain your result. > > > > I am skeptical that ADM is sensitive enough for that. But I am still > not sure if I am using it to maximum effect... would like to see less > variance between runs. It would be cool if somebody made a software > jitter simulator so you could just turn it up until it's audible. > > Anyway, if you're not convinced about the SNR effect, there are much > simpler tests that you can do for that, eg a sine wave and some > analyzer software. Somebody did this with an SB3 once, and got the same > result that I got with ADM. Ah, here it is: > http://mysite.verizon.net/forumwebspace/RightMark/Test%20Reports/Volume.htm
Sean - I figured out what I was doing wrong - On my digital volume test I'd forgotten to change the evaluation frequency range in ADM from its default of 100Hz to 12kHz. I've just rechecked and I get the same results trend as you if I use the full frequency range. One conclusion from that might be that much of the intrinsic noise from DAC and ADC that is boosted (as the SNR decreases) is HF in nature? (I certainly can't hear it, but I can see it in Audacity). This is probably when you tell me that you were only testing with the 100Hz-12kHz range too :) Cheers Phil -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... SB3 (wired) - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods) - Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Townsend Supertweeters, Blue Jeans Digital,Kimber Speaker & Chord Interconnect cables Outdoors: Boom ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=60041 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
