how to convert bitrate on mp3 files to 320 kbps

how do I convert bitrate to 320 kbps on my mp3 files, i have tried to use audio converter studio 6.0 but it only converts 10 files at a time. thanks in advance.P.S. it must be free.

Wait, you want to raise the bitrate of existing mp3 files to 320 kbps? Don't bother. You're not going to magically get higher audio fidelity by raising the bitrate. It may even sound worse as a result.

Replying to #2

ok... darn