http://www.mp3-box.org/mp3-bitrate-conversion/
mp3 sound quality bitrate?
I bought mp3s from amazon. I know that they are usually 256 vbr files. I decided to convert them to 192 kbps bitrate. Does this conversion affect sound quality. If so, should I convert them back to 256 bitrate.
I honestly don’t hear a difference, but I was just wondering before I decide to convert the rest of my mp3 collection.
Best thing to do would be to archive your 256 kbps copies before doing anything else with them.
Most likely you would only be able to tell the difference between the 192 and 256 versions on a high-end stereo system.
One important note is that converting formats like MP3 is *always* lossy—you are essentially tossing out information by converting down to 192. Converting up to 256 does not reclaim that lost information, it just makes the file bigger for the same actual quality.
MP3 Quality Modifier 1.0 – Short demo