Because of the discussion above about mp3 bit rates (128K, etc) vs PCM sampling rates (44.1K, 48K, 96K, 192K) I'm not sure if this is now clear or not:

Masters are prepared and presented at 24-bit, 44.1K and 48K all the time: 44.1k for CDs; 48K for video. 96K is not a minimum standard for either. This is PCM audio, not mp3.

If you are planning Blu-Ray or some other hi-def format like DVD-Audio, then 96K becomes more important, but still not a requirement.

96K is sometimes used on original tracking sessions done by major labels or audiophiles for recording acoustic instruments since there is some evidence that the difference between 44.1K and 96K (or even 88.2K) is audible mainly when recording acoustic instruments.

I haven't recorded at 192K (PCM, not mp3) myself, but have read many articles by people who have tried it. Not a single person was able to hear any difference between the 192k and the 96k recording. I haven't heard anyone recommending it. The only times I've heard of it being used at all are when recording symphonic ensembles where the ambience might gain a bit of detail with that high of a sampling rate.

Mastering facilities will readily accept virtually all sample rates from 44.1 to 192K.

Of course, all that fidelity is lost when you convert it to an mp3 file of just about any bandwidth (128, 160, 192, etc).

Here is a link to an article on preparing your music for mastering:

http://www.discmakers.com/products/preparingyourorder/mastering.asp

Although Discmakers prefers to receive audio CDs at 44.1K/16-bit, I know that most mastering facilities prefer 44.1K/24-bit wav or aif files.



Larry
http://www.audibleresponse.com
http://www.myspace.com/larrywilliamsproductions
...now writing/producing with Natascha: http://www.myspace.com/nataschacorrigan