[igotnojob]

I have a 27" (late 2010) iMac and I had a question about the setting to leave the output of Audio MIDI Setup. I have the Yulong D100 DAC (supports 24-bit/192KHz input) and would be connecting through the iMac's optical output.
 
I have quite a few 24/96 and 24/192 files (though most of my files are 16-bit) that I would like to play back through the iMac. I do not want to spend the extortionist fees for Sound Studio Amarra. I want to set the output settings in Audio MIDI Setup ONE TIME and never have to change them again.
 
My understanding is that iTunes will resample the files' output to whatever the output settings are in Audio MIDI Setup before pushing that signal out of the iMac's optical connection. If I set that output to 24-bit/96KHz, will iTunes upsample 16-bit/44.1KHz files and downsample 24-bit/192KHz to match the 24/96 setting in Audio MIDI Setup?
 
I am guessing that 16/44.1 upsampled to 24/96 will sound better (or at least undergo less degradation) than 24/96 downsampled to 16/44.1. Is that correct? Should I set Audio MIDI Setup to 24-bit/192KHz instead or will the upsampling of 16/44.1 to 24/192 degrade the SQ more than the upsampling of 16/44.1 to 24/96?
 
Am I correct in thinking that changing the output setting in Audio MIDI Setup will make that change permanent until I manually change the setting again? It will not reset by itself? Any help would be appreciated.

 

[Roseval]

 
Quote:

 Am I correct in thinking that changing the output setting in Audio MIDI Setup will make that change permanent until I manually change the setting again? It will not reset by itself?

 Correct.
If you want automatic sample rate switching have a look at http://www.channld.com/puremusic/index.html
 
I wonder if Toslink is capable 192 kHz

 

[MadCow]

Quote:

 
Quote:

 Am I correct in thinking that changing the output setting in Audio MIDI Setup will make that change permanent until I manually change the setting again? It will not reset by itself?

 Correct.

 
Well, mostly correct.
 
Except in some cases where unplugging a USB audio device or DAC and then plugging it in might reset the setting.
 
And some buggy software (like Plex 0.8.5) always resets it to 48/16.

 

[igotnojob]

Thanks for the clarification. I tried the demo of Pure Music and I thought its interface was a bit cumbersome and obtrusive for my tastes. It does seem the better deal at $129 compared to Amarra though. I do like the idea of auto sample switching but I can live with resampled music as long as degradation of the SQ is not significant.
 
The Yulong D100 does, indeed, accept up to a 24/192 signal via its Toslink optical input. Any opinions on whether I should set Audio MIDI Setup to 24/192 or 24/96? Will 16/44.1 sources sound worse resampled to one or the other? I have relatively few 24/192 files. Most of my high res music is in 24/96. Maybe that is the optimal output setting.

 

[Yoga Flame]

Upsampling on the DAC helps to remove jitter. So it makes sense to me to avoid upsampling on the OS where possible and let the DAC do its thing. My problem was I had a mix of different sampling rates in my collection. I did a bit of informal experimenting some time back and got these results:
 
44.1 / 16 --[OS upsample]--> 96 / 24  == no audible difference
44.1 / 16 --[OS upsample]--> 44.1 / 24 == no audible difference
96 / 24 --[OS downsample]--> 44.1 / 16 == sounded worse
96 / 24 --[OS downsample]--> 44.1 / 24 == no audible difference
 
So I settled on using 44.1 khz / 24bit in my audio MIDI settings as a compromise. My Mac is an older model with a max sampling rate of 96 khz using optical out.
 
If anyone else tries this do post the results here too as I'd be interested in seeing if others have the same experience.

 

[cmfhsu]

I believe the program has ultimate control over sample rate conversions in a mac. Unless you open a program, then go and change the audio midi settings, the output will be whatever the audio file is recorded at. What I do is set the audio at the maximum (24/96 for me) in audio midi setup, open my music player (songbird), make sure there will be no resampling in the program, and play files at 100% volume, to ensure bit perfect playback. When audio files are not 24/96, I believe songbird automatically outputs 24/44.1 (or whatever sample rate it is) without automatically upsampling it.
 
I could be wrong, though, as I haven't used a mac for audio in a while...

 

[MadCow]

Quote:

I believe the program has ultimate control over sample rate conversions in a mac. Unless you open a program, then go and change the audio midi settings, the output will be whatever the audio file is recorded at. What I do is set the audio at the maximum (24/96 for me) in audio midi setup, open my music player (songbird), make sure there will be no resampling in the program, and play files at 100% volume, to ensure bit perfect playback. When audio files are not 24/96, I believe songbird automatically outputs 24/44.1 (or whatever sample rate it is) without automatically upsampling it.
 
I could be wrong, though, as I haven't used a mac for audio in a while...

Not quite.
 
If you leave audio/midi at 24/96 and then have the player play 24/44.1 without SRC, then CoreAudio will perform the SRC.
 
Ideally the playback software will change audio/midi's setting depending on the source format, but only a few players are able to do so (I believe Amarra is one of them).
 

 

[Jim_T]

Can one even select 24/192 in audio midi setup for the built-in digital output? I don't have anything hooked up to mine right now, and it shows 24/96 max.

 

[MadCow]

Quote:

Can one even select 24/192 in audio midi setup for the built-in digital output? I don't have anything hooked up to mine right now, and it shows 24/96 max.

Not that I know of. Both my MacBook Pro and Mac Mini can go up to only 24/96 with the built-in optical out.

 

[museamp]

The newest Macbook Pro Thunderbolt Version will input/output SPDIF TOSLINK OPTICAL 24 Bit 192KHZ I/O in  Audio Midi Setup Snow Leopard 64 Bit Logic Pro in 64 Bit very Low Latency. Soon FCP in 64 Bit. The  i7 Quad core chip in the new ThunderBooks have integrated INTEL HD AUDIO that handles 32 Bit 192 KHZ  X 8 . So Mytec 192 ADC or others In. Audiophile DAC out whatever your flavor Prism, Mytec, Crane Song or Weiss. 
 
 
Tommy Hollister
 

 

[doolak]

Hi there,
 
i have the problem that my settings are allwas resetted after restart - if i set the format to 96000Hz / 24bit it will be resetted to 44100Hz / 16bit after restart.
 
I tried several "fixes" - deleted the plist files in Library/Preferences/Audio, deleted the complete Audio folder and recreated it with the terminal and tried a PRAM reset: no success.
 
I have no idea which application could maybe reset the settings after restart - to check even that possibility i deleted a NI Hardware Tool and the iTunes Helper from the login items - but still the same problem.
 
 I tried Amarra and its autodetect changes automatically from 44100 to 96000 Hz - but i have to change from 16 to 24 bit allways manually within the Audio Devices settings..
 
Anyone an idea how i can make my iMac remember those settings?
 
Kind regards,
 
Christian

 

[DarkSleip]

try using Decibel to play music, as it somehow manages the sampling better the difference will be audible and the sample rates will change automatically

 

[Mediahound]

I've been told you always want to match the bit and sampling rate of the original, ie 44.1 and 16bit for ripped CDs. iTunes will only play a track bit-perfectly if Audio MIDI Setup's sample frequency matches that of the track being played. 
 
If you set it to higher, your OS will resample it but there can be quality loss in that process since it's mis-matched. 

 

[DarkSleip]

You should be able to bypass the OS's sampling rate. But it doesn't really matter as it is possible to cut off a 192 kHz file down to a 96 kHz sampling rate to get a better audible SQ (as 192 kHz D/A C's are not actually able to process the signal)

 

[tjones1]

This is a very interesting thread because I just got AudioEngine's DAC (along with their A5+) and would like to output 192 kHz from my macbook air with Decibel. Audio MIDI Setup only shows 96 kHz maximum sample rate for the DAC output (and the onboard output for that matter).
 
So, will I not be getting any better output with my DAC since the sample rate and bit depth will be the same? 
 
And DarkSleip, could you explain your comment about DACs not being able to handle 192 kHz? AudioEngine indicates theirs can handle up to 192 kHz but it doesn't even seem selectable with Audio MIDI Setup.
 
Also, is there a way to bypass the Audio MIDI Setup to get true 192 kHz output that is affordable? 
 
(This is USB output.)
 
Thank you for your time everyone.
 
Tucker