AAC to MP3 for Music Production

Keep MP3 out of the session itself. Lossy files inside a project mean the DAW decodes on import and re-encodes on export, and any processing you apply — EQ, compression, limiting — amplifies the codec's artifacts rather than hiding them. MP3 is a delivery format: reference mixes, client sends, demos on a phone.

One trap catches people out: lossy encoding can push peaks slightly above the source, so a mix sitting exactly at 0 dBFS can clip once it becomes a MP3. Leave about -1 dBTP of headroom on the bounce you encode from — standard practice for masters, and it applies to reference files too.

Never send a lossy file to a distributor or streaming platform. They transcode whatever you upload into their own formats, so handing them an already-compressed file stacks a second lossy generation onto what your listeners actually hear. Deliver lossless; convert to lossy for humans.

Sizes are comparable: AAC and MP3 both sit near 1.2–1.4 MB per stereo minute, so this conversion is about compatibility, not storage. You're stacking a second lossy generation. At a generous bitrate that's inaudible, but if you still have a lossless original, encode from that instead: one generation always beats two.

AAC files come from HLS streaming segments, broadcast pipelines, Android recording apps, and hardware recorders. A bare .aac stream lacks the container index that tells software its duration, so players won't list it and editors import it wrong — which is the whole reason this conversion exists. MP3 is the destination because it plays essentially everywhere — downloads and every ordinary phone, browser, and player. File size stays in the same ballpark — both formats land around 1.2–1.4 MB per minute. Both AAC and MP3 are lossy, so this pair stacks a second encode — at a generous bitrate it stays inaudible, but if a lossless original of the AAC exists, encode the MP3 from that instead.