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Table Of Contents
Chapter 21 Share projects 722
MP3 bounce options
You can bounce projects to MP3 (MPEG-2, Audio Layer 3) format les. The MP3 format was
developed by the Fraunhofer Institute, and allows high compression rates while maintaining
reasonable audio quality. MP3 is a widely used standard for audio le exchange over the Internet.
Because the MP3 le format involves a loss of audio quality, you shouldn’t use MP3 les during
production if you have access to the same audio data in non-lossy formats such as AIFF or WAV.
Bounced PCM les are also used for encoding to MP3/M4A: AAC. Note that this occurs before
dithering takes place.
Note: The MP3 format doesn’t support sampling rates higher than 48 kHz. If the selected sample
rate is higher than 48 kHz, a temporary copy of the PCM le (with a 48 kHz sample rate) is
created before the project is bounced to MP3 format. If PCM is unselected in the Destination
area of the Bounce dialog, a temporary PCM le is created and used as a source for bouncing to
MP3 or M4A: AAC, or for burning to a CD (depending on which options are selected).
Selecting the MP3 option in the Destination area automatically disables the PCM > Surround
option. This is because the MP3 format doesn’t support surround. However, Split Stereo format is
possible, even if the encoded MP3 le is set to Joint Stereo mode.
When you click MP3 in the Destination area, the following options are available:
Bit Rate (Mono/Stereo) pop-up menus: MP3 bit rates are available between 32 kbps and
320 kbps, but default to 80 kbps mono, and 160 kbps stereo. These rates oer acceptable
quality and good le compression.
For enhanced audio quality, you can choose:
96 kbps for mono streams
192 kbps for stereo streams
You can choose higher rates, but the quality improvement aorded by bit rates above
96/192 kbps is nominal. Note that the higher the bit rate, the larger the le size of the bounce
le will be.
Use Variable Bit Rate Encoding (VBR) checkbox: Variable Bit Rate encoding compresses simpler
passages more heavily than passages that are (more) harmonically rich, generally resulting in
better quality MP3 les.