darrenyeats wrote: > Dither is still the correct way to do volume control ...! Because I want > to play anything, over a usable volume range, without worrying about it. > > I'll add something here. Though I accept you might live within the > limits of the SB and Transporter volume controls, I'm not sure about the > Touch ...! > > I'm given to understand it's SqueezePlay that runs on the Touch, is this > true? From what I've seen of the SqueezePlay code, it uses a two part > scale where 0=-74db, 25=-37dB and 100=0db and volume steps divided > equally in dB in each scale. You can see the first part ramps rapidly. > This actually fits with my user experience with the Touch. Until someone > can explain otherwise, (_edit_*) I think the Touch likely truncates at > every volume level below 100, with 16 or 24 bit sources. > Darren > > *Thanks Julf.
That's only half true. 1. Yes, SqueezePlay does have two overlapping volume ramps and there's actually even a volume level at which increasing the "logical" volume level by one decreases the actual volume level. The reason for this is that you want different levels of volume change for high and low relative volume levels. A "linear" (of course it's actually logarithmic) change would either have too big steps at high volume levels or too small steps at low levels. So if you don't like the ramp using an external volume control might help. 2. SqueezePlay never clips with 16 bit material. The reason is simple: it doesn't divide but multiplies with pre-divided scale factors from a scaling table. This is an in-range multiplication which never clips and doesn't lose any accuracy, the scaling is exact. There is no noise being added whatsoever. So with 16 bit material dithering doesn't make any sense from a noise perspective. 3. For 24 bit material EVERY volume control will clip, even a dithering one. It does clip at -144dB, though so if any your dithering effect will be a noise "optimization" (it's not a reduction because as mentioned before dithering itself is just adding noise, too) of -147dB. Worthwhile all the hassle? --- learn more about iPeng, the iPhone and iPad remote for the Squeezebox and Logitech UE Smart Radio as well as iPeng Party, the free Party-App, at penguinlovesmusic.com *New: iPeng 9, the Universal App for iPhone, iPad and Apple Watch* ------------------------------------------------------------------------ pippin's Profile: http://forums.slimdevices.com/member.php?userid=13777 View this thread: http://forums.slimdevices.com/showthread.php?t=104629 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
