The first thing to learn about audio encoders is:trash in -> trash out. Audio encoders will not magically improve a signal.
The second thing to learn about audio encoders is:lossy to lossy (spelled transcoding) = lower quality. Encoding a file that was previously encoded with another lossy encoder lowers the quality (some times is not perceptible, others is annoying).
So if you add lesson 1 and lesson 2, you've got that your mp4 (m4a) converted to mp3 has less quality than the mp4 it started from. Using V0 will not make it any better if what you started with is a 128kbps mp4.
If you had started from an original file (like, from a comercial CD), then, you could still get low bitrates with V0, but then, the reasons are: small complexity (some types of classical music, or similar), and/or being nearly mono.
So what would be the best way/utility to convert m4a to mp3?
How does it sound? V0 should be very good, and LAME is "smart". It will use a higher bitrate if needed for sound quality (or if a highter bitrate would help sound quality). If a lower bitrate won't affect sound quality, it will use a lower bitrate which will give you smaller file.
QuoteSo what would be the best way/utility to convert m4a to mp3? Data is lost every time you compress with lossy compression. The original compression to M4A was lossy and you're introducing another lossy compression step. (This does NOT mean that you ALWAYS hear "audio quality" loss... But the original audio data is gone and you can't get that exact-original data back.)
I thought M4A was "Apple Lossless Audio"? That's what they are identified as in iTunes.
Quote from: sigrun on 20 October, 2010, 02:47:57 PMSo what would be the best way/utility to convert m4a to mp3?What is your need to convert AAC to MP3? I've found that every player that can play MP3 can also play AAC. If it's a file size issue, my suggestion is just run it through LAME and deal with any artifacts that arise (though you might not notice them anyway).