One way to get better audio quality is to NOT record your original interviews in MP3 format. By recording in MP3 format and then compressing to a lower-bitrate MP3, you're compounding lossy compression. (It's analogous to compressing a heavily compressed JPEG.)

Record in uncompressed AIFF format at 44.1KHz. Edit and tweak, *then* encode your final product into MP3.

And archive those AIFF originals so you can rerelease them on CD someday!

Jim Heid
macilife.com