There are many parameters that add up to great sound: good recording techniques, eq, compression, etc. Professional sound shops have as many tools, plugins, etc for sound as video pros have for editing. You should post this kind of question on the Audio Professionals forum where you’ll get some very good info.
Within most Flash encoding apps there’s an audio selection for kbps which affects audio fidelity. Make sure you’re using at least 64kbps for mono and 128 kbps for stereo. 128 kbps is a fairly standard bit rate for downloaded mp3s, although, some sites are starting to offer 256 kbps as a higher-quality alternative.
Be aware that the audio bit rate adds to the video bit rate and you should know what kind of pipe your viewers will have. You can crank up the overall bit rate, but that might lead to long buffer times, interrupted programs, etc. if the viewer has a slow connection.
John
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