Phil Leigh;398434 Wrote: > Well, the volume control test is proving very interesting! > I'd like to hear from SlimDevices on this one - Sean are you there? > > I took a 24/96 track via SOX so 24/48 at full volume. > Then I dropped the SB volume to 50% and recorded the same track. The > difference shows as -48dB which is quite large...but when I played it I > couldn't hear anything even with 80dB of boost!!! No rise in the noise > floor either! (well there is but its tiny). > > So I opened up the difference file in Audacity and wow! - now I > understand the apparent paradox of a large difference I can't hear... > there's a fairly obvious DC offset introduced on both channels. This > seems plain wrong to me. I'd really like someone else to try this out! > > With the volume set to 9 out of 11 (web gui) there is no difference at > all (sorry all you "full volume" fans) - and NO DC offset. > > With the volume set at 3 out of 9 there is the expected rise in the > noise floor caused by the lowered signal to noise ratio but the DC > offset is bigger than at half-volume! I notice the offset is higher in > the right channel. We are talking about nearly half scale DC here! > > I think I need to take a rest from this for a bit. These results don't > seem reasonable. > > Maybe something is wrong with my soundcard or method? Anyone care to > replicate?
Could that be a bug in the differencing software, rather than in the SB or your soundcard? Maybe when it has to match volumes it introduces a spurious DC offset? You might just record the SB output directly at each volume and just look at it (or take its average) to see if there's an offset. -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=60041 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
