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Does PLAY upsample on playback?

Posted: Mon Apr 13, 2009 4:24 pm
by phrarod
I'm trying to figure out why PLAY sounds so much better on playback than iTunes. I have a high resolution system and the difference is immediate and impressive. I read that "Play processes all audio using 32-bit floating point precision" does that mean its upsampling to 32 bit?

Is it bypassing the MIDI that the Mac uses for output? Someone told me I could change the sample rates for playback there but I never tried it. PLAY is very impressive and I also use it for critical listening. Just wish the interface handled AIFF better as far as meta data.

Re: Does PLAY upsample on playback?

Posted: Mon Apr 13, 2009 9:18 pm
by sbooth
Play converts all incoming audio to 32-bit floats, normalized to a value of +/- 1.0. So for 16 and 24 bit samples, it is essentially a lossless operation. It doesn't bypass anything (like MIDI) directly, but uses the output audio unit specified in the preferences.

Re: Does PLAY upsample on playback?

Posted: Mon Apr 13, 2009 10:02 pm
by phrarod
Out of curiosity what is the bit-float count of iTunes?

Its just amazing how much better your program sounds at playback.

Re: Does PLAY upsample on playback?

Posted: Tue Apr 14, 2009 1:14 am
by sbooth
I do not know what iTunes does internally. Is the iTunes equalizer turned on? Another source of difference could be the preamp, if replay gain is enabled in Play.

Re: Does PLAY upsample on playback?

Posted: Tue Apr 14, 2009 1:19 am
by phrarod
I run iTunes as straight - no EQ. I don't believe reply gain is enabled. There's no difference in sound level between PLAY and iTunes. Just a big SQ difference.

Re: Does PLAY upsample on playback?

Posted: Wed Apr 15, 2009 9:32 am
by RonaldPR
In iTunes preferences (under Playback) one can enable "Sound Enhancer", which does (in my view) the opposite of what the name of that option suggests. Maybe the option "Sound Enhancer" happens to be enabled in iTunes?

Re: Does PLAY upsample on playback?

Posted: Wed Apr 15, 2009 3:10 pm
by phrarod
No. iTunes doesn't have any option checked. I just spend 3 hours with a friend who was trying to beat PLAY with his PC. Never happened no matter how many secret work arounds. One odd thing was iTunes sounded better on the PC than the Mac until I changed some upsampling with MIDI.

Still he's probably going to buy a Mac Mini just to get PLAY.

Re: Does PLAY upsample on playback?

Posted: Sun May 31, 2009 3:08 pm
by indirstr8
I started using the play today on the mac. It is so much better than iTunes. There is something wrong with the iTunes. The following things were not clear to me.

a) In the play output preference I don't see any sample rate/ sample width. How does the play decide what to give out when I am playing 16-bit/44 Khz apple lossless files.
Does it use the settings in the midi to decide the sample rate and sample width.
b) I can see my output USB device in the play output preference. Do I have to set the default output in the midi too?

c) Does the play uses its own sample rate and width converter or just uses the mac os coreaudio stuff.

d) If the midi settings are relevant for the sample width/rate is the order of changing them and invoking play important. In iTunes it is.


Once more it does sound much better than iTunes.