Audio Formats and Quality

A variety of factors affect the quality of a digital audio file; most notably:

The sampling bit rate (how often the audio signal is sampled, expressed here as Kbps)
How, or whether, the file is compressed.

Higher sample rates result in better sound quality, but are usually larger files than those using lower sample rates. Compressed files are smaller but have slightly lower quality than uncompressed files. Different compression formats can also affect the quality. By default, Rhapsody Imports CDs as 192Kbps MP3 files.

The following formats are available in Rhapsody for playback and Importing CDs to My Library, as noted below:

Playback Formats
Format	File Extension	Available Quality Levels	Comments
AAC Audio Secure AAC	.m4p	96 - 320 Kbps Stereo	AAC encoded MPEG-4 audio. Compatible with iTunes and the iPod.
Real Audio 10	.ra .rax	32 - 320 Kbps Stereo	Highest quality, native format from RealNetworks.
Real Audio Lossless	.ra	705 Kbps Stereo	Loses no data, all information in the original file or track is preserved.
MP3	.mp3	32 -320 Kbps Stereo (Default 128 Kpbs)	MPEG Layer 3 Audio. A popular open-standard compression and file format for digital audio.
WAV Audio	.wav	1411 Kbps Stereo	Raw, uncompressed files.
WMA Audio	.wma	64-192 Kpbs Stereo	Windows Media audio file: Microsoft Windows proprietary audio format.




CD Importing Formats
Format	File Extension	Available Quality Levels	Comments
AAC Audio	.m4a	96 - 320 Kbps Stereo	AAC encoded MPEG-4 audio. Compatible with iTunes and the iPod.
MP3 (Default)	.mp3	32 -320 Kbps Stereo (Default 128 Kpbs)	MPEG Layer 3 Audio. A popular open-standard compression and file format for digital audio.
WMA Audio	.wma	64-192 Kpbs Stereo	Windows Media audio file: Microsoft Windows proprietary audio format.

Note: The above information refers only to CD Importing and playback. CDs can only be burned in CD Digital Audio format (.cda) at 128 Kbps. This is the format of a music CD purchased at your local retailer.