Audiophile output on Mac OSX

[Beechwoods]

Airport Express does convert to ALAC and only supports 16/44.1 (some folks have hacked it to handle other sample / bitrates but you need to be a whiz programmer to pull it off).

[webby]

It seem odd that it converts on the fly like this. Are you sure it doesn't just convert the files that are NOT 16/44.1 in order to handle them, and leave all 16/44.1 alone?

[Beechwoods]

I'm sure on the point of converting everything to ALAC. It is daft, but I guess it made the hardware side simpler. The AE itself only needs to handle one codec this way.

[webby]

What if I feed it with ALAC?

[Beechwoods]

As far as I know, Webby, it takes 16/44.1 ALAC without conversion...

[Codifus]

Hi Beechwood,

I think it would be better to say that iTunes, once it knows it is talking to an airport express, converts its audio data, be it MP3, AAC, AIFF or WAV, to ALAC. iTunes then sends the ALAC data to the airport express. The airport then expands the data back to PCM audio which it either sends to its internal DAC or S/PDIFs thru optical to an external DAC.

This is done in an effort not to saturate the limited wireless bandwidth available thru the G or N protocol.

[tr@nz]

Just a little update from things I have gleaned over the last few months that might interest those reading this thread.

1. A program, albeit pricy at $995, called Amarra (by Sonic Studio - pro audio) is supposed to make iTunes sound even better. Moreover, it is supposed to do the file resolution switching automatically for you. If you have 24/192, 24/96 and 16/44.1 files sitting on your server, you do not have to keep switching your Audio/Midi settings. Have not listened or purchased it.....yet.

http://www.sonicstudio.com/amarra/

2. There are many threads, magazine articles and tests out there that state firewire connection to your DAC beats USB and optical. Something to think about.

3. I have used 24/192 on iTunes without issue. Currently using Mac Mini firewire to AES/EBU to an external DAC.

4. There are some decent options out there for getting high-res audio purchased on the web, although mostly in the classical and jazz arena. Most of these sites have some free trial songs for you to play with.

- http://www.2l.no/
- http://www.highdeftapetransfers.com/
- http://www.itrax.com/
- http://www.linnrecords.com/
- http://referencerecordings.com/
- http://www.aixrecords.com/aix_news.html
- http://bluecoastrecords.com/blue-coa...6khz-downloads

5. Another option is to rip your high res audio from BluRay. The 2l production company in Norway now also sells blu-ray audio only discs with 24/192 resolution files.

6. Airport Express is cool to use with iTunes, as you can use your iPhone remote application to even turn on which "speakers" to use. The airport express is just seen as another speaker. Slick. It is a pain in the @@s to setup the Airport on the network though, so don't lose patience as I almost did. But you are stuck with 16/44.1.

7. Using SSD drives apparently helps the sound quality too. Just learned about this, so I will be trying that soon.

This is an exciting time for the music server.

Hope this helps.

Cheers!

[Peter H]

I'm a Mac user and only just found this item. Very useful. Thanks.

[ultraviolet]

I've been reading this thread with great interest as I got hold of a mac mini to replace my old (450 MHz) windows music PC a few weeks ago.

On the subject of bit perfect playback the attached file is a comparison of an original wav file as played on the mini using itunes and a recording made via spdif on my macbook using soundstudio (demo version) and saved as a wav. Done all the usual tweaks suggested in this thread (thanks everyone); set output to 44.1, turn off sound enhancer/sound check, volume at full.

The files are very slightly different in a couple of places by one (probably inaudible) bit. Any suggestions?

[Beechwoods]

Could be error correction within the SPDIF stream, or jitter. Optical connections are better in some respects in that they resist electromagnetic interference, unlike wired digital connections, but this comes at the price of the electronic signal to light conversion, which can introduce it's own subtle changes.