User guide

Chapter 27 Bouncing Your Project 631
MP3 Options in the Bounce Window
Logic Express allows the bouncing of MP3 (MPEG-2, Layer-3) format files. This well-
known data reduction format for digital audio signals was developed by the Fraunhofer
Institute, and allows high compression rates while maintaining reasonable audio
quality (depending on the compression rate). MP3 is a widely used standard for audio
file exchange via the Internet.
Due to the fact that encoding an MP3 file equates to a loss of audio quality, you should
not use MP3 files during production if you have access to the same audio data in linear
formats such as: AIFF, WAV, or SDII.
Bounced PCM files are also used for encoding to MP3/M4A: AAC. It should be noted
that this occurs before dithering takes place.
Note: Should the selected sample rate be higher than 48 kHz, a temporary copy of the
bounced PCM file is created—with an automatic sample rate conversion to 48 kHz
before encoding. This conversion takes place because the MP3 format does not support
sampling rates higher than 48 kHz.
If the PCM option is disabled in the Destination pane, a temporary PCM file is bounced
as a source for encoding to MP3/M4A: AAC and/or burning to a CD—in accordance
with the options selected in the PCM page.
Choose the MP3 name (and activate the checkbox) in the Destination pane to access
the following options: