I was wondering if its possible to upgrade the bitrate of a mp3 say a 128 to a 192, or a 192 to a 320. I did a search and couldnt find anything in afterdawn so if anyone knows how please let me know
You can do it, but it's stupid. The 192kbps will sound worse than the 128 "original". MP3 is lossy: everytime you encode, you lose quality.
True that changing an MP3 will result in quality loss but if you only change it the once to a higher quality sound with your prefered settings then the lossy format sound quality loss will be negligible and worth it. Especially if you have lots of mp3's of varying quality. The best compromise on size and quality would be 16 bit (burning programs won't burn higher than 16 bit), 192khz (best compromise for size if you have a large collection) at 44.1khz (this is the standard) 48 khz is a slightly better sound but might not work with some mp3's
Why on earth should anyone want do do this? Waste space and introduce/enhance artifacts? What exactly is this profit that is worth it? You might want to read the sticky thread List of recommended LAME MP3 encoder settings - the highest quality MP3 encoder. Upsampling to 48KHz is no good, because - You can't create something out of nothing - Lame (best Encoder for bitrates you suggest) isn't tuned for 48KHz and performs worse.
And most CD burning softwares have hard time decoding and downsampling 48->44.1kHz, which results in decreased sound quality.
