MP3 to AAC for Music Production

Keep AAC 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. AAC 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 AAC. 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.

Disk usage barely moves — this conversion buys compatibility rather than space. Two lossy formats in a row means two rounds of the encoder guessing what you won't miss. At a high bitrate the second guess is harmless; at a low one it compounds.

MP3 is the format of downloads. It plays where it was made, but MP3 is lossy and built for playback, so editing, production, and some apps and engines want a different format. AAC is the destination because it plays essentially everywhere — HLS streaming segments and every ordinary phone, browser, and player. Expect a similar file size; the reason to convert is playback and workflow, not disk. Both MP3 and AAC are lossy, so this pair stacks a second encode — at a generous bitrate it stays inaudible, but if a lossless original of the MP3 exists, encode the AAC from that instead.