Phil Leigh;695205 Wrote: > Dither is only (these days) relevant when downsampling from 24 to 16 > bits. It determines what happens in what I call the lowest half-bit. It > pseudo-randomises it, which helps avoid quantisation distortion becoming > apparent on very quite things like in fade outs, reverb tails etc. > > > What you are seeing in that Stereophile trace are exactly the > distortions caused by the fact that the16-bit signal was NOT dithered > when it was created from a 24-bit starting point. That's why they have > to make the point of saying it is "undithered". > It also neatly illustrates why dithering is a good idea when > downsampling :-) > > Those jagged edges Simply do not exist as you increase the number of > bits in play. You will notice that Stereophile do not show you what a > sine wave looks like at higher levels... That's because it looks > exactly like a very nice sine wave!!!!! > > > I can see this clearly on my oscilloscope... The sine wave is fine all > the Way down until you run out of meaningful bits...
True. That 16-bit -90dB tracing at 1kHz is just to show the DAC's linearity down to the last bit. It's undithered and EXTREME to show how cleanly the DAC can flip that least significant bit in a 16-bit signal. It's nice to show off good DAC design: Transporter - nice and clean like Benchmark DAC1: http://www.stereophile.com/content/slim-devices-transporter-network-music-player-measurements Touch - clearly less clean but I'm not sure how audible this would be: http://www.stereophile.com/content/logitech-squeezebox-touch-network-music-player-measurements Remember just how extreme this test is and not get hung up about it since it is at -90dB and inaudible. I can see many non-technical folks will point to this and say just how bad 16-bit music is compared to 24-bits; hogwash! For actual audible material, the waveform will look nothing like this as Phil noted. -- Archimago ------------------------------------------------------------------------ Archimago's Profile: http://forums.slimdevices.com/member.php?userid=2207 View this thread: http://forums.slimdevices.com/showthread.php?t=94054 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
