4 Replies Latest reply: Jul 12, 2006 8:45 AM by David S.
JDIRECTORJ Level 1 Level 1 (0 points)
I have completed a music video in FCP and now compressed it in compressor. I chose the audio in AC3 and AIFF. Why is it that the AIFF sounds better and at a higher volume level than the AC3. Isn't the AC3 supposed to be higher quality. And doesn't dolby give a better sterio sound?

Mac OS X (10.4.7)
  • David S. Level 7 Level 7 (20,630 points)
    Did you create a custom preset for Dolby2/ac3 that uses -31 normalization.

    AC3 is a compresssed format that many people cannot distinguish from aiff, which is not compressed.
  • JDIRECTORJ Level 1 Level 1 (0 points)
    Okay I will check the normalization thing. Is the only difference between AC3 Dolby 2.0 and AIFF the compression. Why would I ever used the Dolby?
  • Jonathan Frank2 Level 1 Level 1 (125 points)
    You'd use it BECAUSE it's compressed, thus saving you valuable DVD real estate. An AIF file for your project that takes 800MB worth of space can be replaced by an ac3 file that sounds almost identical, yet takes up only 100MB (of course all this depends on the settings you use for the compression, but it's a close estimation)
  • David S. Level 7 Level 7 (20,630 points)
    Because aiff contributes to the combined throughput of the DVD seven times more than ac3.

    That affects compatibility and performance with set top players