NO MP3 or other compressed file formats!!! We can work with .AIFF or .WAV formats but we prefer the international cross-platform .WAV format. This format is an international standard that has a lot of meta data (like the tempo it had when it was recorded) that makes working with the files a lot easier. Bit depth and sample rate are totally up to you to decide and depend on the recording equipment you use, for us it can 't be more then 24 bit or 192kHz. (the higher the bit depth and sample rate the higher the quality of your recording) CD quality is 16 bit and 44.1 kHz, we prefer to work at 24 bit and 96 kHZ