Thanks for the responses gents!

Would you happen to know how the WMA's are encoded?



Example:

Windows Media Audio 10 Professional
Windows Media Audio 10 Professional (WMA 10 Pro) is the most flexible Windows Media audio codec available – supporting profiles that include everything from full-resolution 24-bit/96 kHz audio in stereo, 5.1 channel, or even 7.1 channel surround sound, to highly efficient mobile capabilities at 24 Kbps to 96 Kbps for stereo, and 128 Kbps to 256 Kbps for 5.1-channel sound. WMA 10 Pro offers incredible quality for consumers using high-fidelity hardware and 5.1 channel surround sound-equipped computers -– and for consumers playing audio content on their mobile devices. WMA 10 Pro supports streaming, progressive download, or download-and-play delivery at 128 to 768 Kbps.

For more information about the mobile capabilities in WMA Pro and how it compares to other audio codecs, see the NSTL Test Report.

When using 5.1 surround sound audio compressed at 384 Kbps with WMA 10 Pro, most listeners cannot discern any differences between the compressed music and the original pulse code modulation (PCM) files. WMA Pro also offers dynamic range control using the maximum and average audio amplitudes that are calculated during the encoding process. Using the Quiet Mode feature in Windows Media Player 9 and later, users can hear either the full dynamic range, a medium difference range up to 12 decibels (dB) above the average, or a little difference range up to 6 dB above the average.

If a user tries to play back a file that was encoded using the 5.1 channel, 24-bit, 96 kHz sampling capabilities, but does not have a system or sound card that supports multi-channel or high-resolution sound, multiple channels are combined into stereo audio (for example, 16-bit, two channel audio), ensuring that users get the best playback experience their systems can provide.

The following table compares WMA Pro to competing compression technology.

Audio Data Industry Compression* Windows Media* Compression Savings
2 ch x 48 kHz x 16 bits
Dolby Digital 2.0 at 220 Kbps
WMA 10 Pro at 128 Kbps
1.7:1

6 ch x 48 kHz x 20 bits
Dolby Digital 5.1 at 384 Kbps
WMA 10 Pro at 192–256 Kbps
1.5–2:1

6 ch x 48 kHz x 24 bits
DTS 5.1 at 1,536 Kbps
WMA 10 Pro at 768 Kbps
2:1