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Diatribe

macrumors 601
Jan 8, 2004
4,256
44
Back in the motherland
This is a long thread that wonders all over the place. I will assume the issue about iTunes not being an audiophile solution is still at hand. So, I will give my two cents on this one.

iTunes 7.5 is an audiophile solution that can output bit-perfect audio. Stereophile and the engineers at Benchmark Media Systems have been discussing the version 7.5 issue for about a month and they have provided the solution.


I am not tying to shamelessly plug my own site, but I have discussed this several times and will point out two of the articles regarding this topic.

http://www.computeraudiophile.com/node/87

http://www.computeraudiophile.com/node/78

Thanks for the info. Seems like everything is good, interestingly enough I had to change mine to 96kHz.
The only thing I'd love to know is how the appleTV fares since you cannot really change anything there.

Nice site btw.
 

Tarkovsky

macrumors 6502
Original poster
Jan 4, 2007
314
0
London/Norwich
I don't mean to be rude, but you've missed the point - it's itunes 7.5 that has the problems REGARDLESS of audio midi settings. Try comparing it to VLC or itunes 7.4.
 

Audiofile

macrumors newbie
Dec 26, 2007
15
0
I don't mean to be rude, but you've missed the point - it's itunes 7.5 that has the problems REGARDLESS of audio midi settings. Try comparing it to VLC or itunes 7.4.

Tarkovsky - Are you still suggesting iTunes is failing audiophiles and is not bit perfect even though some of the best engineers in pro & consumer audio have said there is not a problem as long as the MIDI setting are set correctly? Or, are you saying VLC sounds better to your ears as a subjective opinion? Just wondering where you are coming from.

I don't think VLC even compares to iTunes. They are apples and oranges.
 

Tarkovsky

macrumors 6502
Original poster
Jan 4, 2007
314
0
London/Norwich
Though this has been explained earlier, I'm quite happy to answer your question. Itunes 7.5 is not bit perfect and uses OSXs sample rate conversion even when the audio midi settings are set correctly. This is new in 7.5. I use 7.4.
 

Audiofile

macrumors newbie
Dec 26, 2007
15
0
Though this has been explained earlier, I'm quite happy to answer your question. Itunes 7.5 is not bit perfect and uses OSXs sample rate conversion even when the audio midi settings are set correctly. This is new in 7.5. I use 7.4.

I disagree, as do many others. Can you give us an idea of where you are getting this information to support your opinion?

Recommended Setups from Benchmark Media Systems:

Optimal settings for iTunes differ depending on the capabilities of the audio output device being used. The following recommendations are for the Benchmark DAC1 USB and other devices whose computer interfaces are capable of 96-kHz, 24-bit operation.

The Volume Control in iTunes v7 is very-high quality under both operating system. It is very well designed and operates at 24-bits for audio devices that support 24-bit operation. The end user should not hesitate to use the volume control in iTunes 7.x under either operating system.

For users of iTunes under Mac OS X with 96/24 output devices, we offer the following two different, recommended solutions:

The ‘Set It And Forget It’ solution for iTunes 7.x: Before opening iTunes, set the sample rate of CoreAudio (in AudioMIDI Setup) to 96 kHz. Do not change the sample rate of CoreAudio unless iTunes is restarted after the change is made. This solution will prevent CoreAudio from applying SRC, as the quality of CoreAudio’s SRC is horrible. Also, by having iTunes locked at 96 kHz, all audio with sample rates below 96 kHz will be up-sampled to 96 kHz. This will cause virtually no loss in sonic quality, as the quality of iTunes’ SRC is very good – virtually inaudible. Also, by avoiding down-sampling by iTunes, this setting will never result in a loss of bandwidth (except with sample rates greater then 96 kHz).

The ‘Bit-Transparency For Each Sample Rate’ solution: *CAUTION: This solution is rather cumbersome, offers virtually no quality improvement over the first solution, and can easily be mis-configured which can cause severe distortion. Before opening iTunes, set the sample rate of CoreAudio (in AudioMIDI Setup) to that of the audio you will be playing. Do not change the sample rate of CoreAudio unless iTunes is restarted after the change is made. This solution will prevent CoreAudio from applying SRC, and avoid SRC by iTunes for all audio with the same sample rate at which iTunes is fixed.
 

khollister

macrumors 6502a
Feb 1, 2003
541
39
Orlando, FL
Something is still odd - I set up the CoreAudio sample rate to be 44.1, restarted iTunes 7.5 and set the OS volume and iTunes volume to 100% and hooked up one of my headphone amps with my Sennheiser 600's. I also fired up Play (from Stephen Booth which is recommended by Linn for FLAC playback). There is a noticeable difference in sound, even through the crappy iMac internal DAC. I am going to delete iTunes and install 7.4 to see what happens. This supposedly sidesteps the sample rate conversion issue as well as any doubt about the volume control. Play sounds distinctly better. I am using AAC lossless files.

Keith
 

Tarkovsky

macrumors 6502
Original poster
Jan 4, 2007
314
0
London/Norwich
All my 'testing' is subjective. Which is the most accurate kind of testing. I use an optical into cambridge audio 540r and some kef codas for the moment. Most of my music is apple lossless ripped using the CD paranoia codec in MAX from sbooth.org. My imac is v6.3 (white plastic 24).
 
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