What bit rate to use? Mac laptop--> Optical--> DAC
Sep 12, 2009 at 7:38 PM Thread Starter Post #1 of 5

moogoob

Headphoneus Supremus
Joined
Mar 21, 2008
Posts
2,023
Likes
12
Hey all, I'm just curious as to what my settings in Audio Midi Setup should be for playing normal CD-quality files over an optical connection- should I use the exact setting (16bit, 44.1khz) or is it okay to set it higher without the system doing something funky to the sound? I ask this as it has to be set higher to play higher-resolution files, so if I can keep it at a nice high setting it would be more convenient.

If not, I can just change it back and forth as I need to. I don't listen to hi-res files that often.
 
Sep 12, 2009 at 9:40 PM Post #2 of 5

flatmap

500+ Head-Fier
Joined
Aug 31, 2006
Posts
846
Likes
40
Are you using iTunes?

Here's the way I think it works, based on what I've read on various forums. When you launch iTunes, it reads the settings in Audio Midi Setup. If a given song has the same sample rate as this initial Audio Midi setting, then all is fine.

However if the iTunes track that you're playing is not at the same sample rate as Audio Midi Setup (as determined at the time of iTunes launch), then iTunes will resample the track in order to pass it at the same sample rate. So resampling happens, in this case.

If you change Audio Midi Setup while iTunes is open, then iTunes will continue to try to match the sample rate of the initial Audio Midi Setup values. However, the Audio Midi settings are now different than the original. So the consequence is that Audio Midi Setup is receiving something other than what it expects -- and so it will also resample to get that incoming stream from iTunes reset to the sample rate that it has now been set at. So it's possible to end up forcing the over all system to resample twice.

If you want to change the Audio Midi Setup sample rate -- and you want to do this cleanly -- then you need to exit iTunes, change Audio Midi Setup sample rate, and then reopen iTunes. And what a bother this is!!!

Many feel, by the way, that when iTunes resample that it does a better job than when Audio Midi Setup resamples. However I have also heard others say that they like it when iTunes upsamples a 44.1 kHz track to match a 88.2 kHZ Audio Midi Setup setting. YMMV.
 
Sep 12, 2009 at 9:51 PM Post #3 of 5

moogoob

Headphoneus Supremus
Joined
Mar 21, 2008
Posts
2,023
Likes
12
Quote:

Originally Posted by flatmap /img/forum/go_quote.gif
Are you using iTunes?

Here's the way I think it works, based on what I've read on various forums. When you launch iTunes, it reads the settings in Audio Midi Setup. If a given song has the same sample rate as this initial Audio Midi setting, then all is fine.

However if the iTunes track that you're playing is not at the same sample rate as Audio Midi Setup (as determined at the time of iTunes launch), then iTunes will resample the track in order to pass it at the same sample rate. So resampling happens, in this case.

If you change Audio Midi Setup while iTunes is open, then iTunes will continue to try to match the sample rate of the initial Audio Midi Setup values. However, the Audio Midi settings are now different than the original. So the consequence is that Audio Midi Setup is receiving something other than what it expects -- and so it will also resample to get that incoming stream from iTunes reset to the sample rate that it has now been set at. So it's possible to end up forcing the over all system to resample twice.

If you want to change the Audio Midi Setup sample rate -- and you want to do this cleanly -- then you need to exit iTunes, change Audio Midi Setup sample rate, and then reopen iTunes. And what a bother this is!!!

Many feel, by the way, that when iTunes resample that it does a better job than when Audio Midi Setup resamples. However I have also heard others say that they like it when iTunes upsamples a 44.1 kHz track to match a 88.2 kHZ Audio Midi Setup setting. YMMV.



Thanks for the answer. So, to keep it safe for now I'll just have to keep switching. iTunes' up-sampling certainly doesn't sound bad, but I suppose I'll stay on the safe side, as my DAC up-samples anyways and I'd like to keep the amount of re-processing to a minimum.

Thanks once again.
 
Sep 13, 2009 at 5:58 AM Post #4 of 5

flatmap

500+ Head-Fier
Joined
Aug 31, 2006
Posts
846
Likes
40
I really hope that Apple makes this easier on us, some day. It's quite a nuisance to be quitting and restarting iTunes.

I gather Amarra manages to take care of this automatically with their player -- but that's still a bit rich for me. But just ot have this convenience... well that's worth something for sure. Anyway the fact that they've figured it out means that others will follow suit.
 

Users who are viewing this thread

Top