Howtosignalprocessing
Can I convert 128kbps to 320kbps?
You can't just re-output them at 320kbps. The new file will be a lot bigger, but won't contain a single byte of musical information more than the 128kbps version. Bigger file, no increase in audio quality. In other words, it's a totally pointless exercise.
Does converting audio files lose quality?
You are, in effect, converting from one lossy file format to another. In most cases, there will be additional loss during the conversion, but most people will not be able to discern the difference. Every conversion will reduce audio quality.
