Convert and Normalize Audio with SoX
Use SoX — 'the Swiss Army knife of audio manipulation' — to transcode between formats, resample, and normalize gain in one pipeline.
Run sox input.wav output.mp3 to convert formats, and sox input.wav output.wav gain -n -3 to normalize the peak level to -3 dB.
01Command
Command
$ sox input.wav -C 6.5 output.mp3
gain -n -3 output.mp3 # normalize peak to -3 dB (as second pass)02What it does
sox reads input files, applies effects left to right, then writes the output; the format is inferred from the file extension, and -C sets the compression quality when encoding MP3/ogg. The gain effect with -n computes the gain needed to reach the target peak (-3 dB here) without clipping. Effects chain naturally, so things like sox in.wav out.mp3 gain -n -3 rate 44100 convert, resample, and normalize in one call.
03Risk
!Warning: Debian/Ubuntu's base sox package omits MP3 support — install libsox-fmt-all or conversions to MP3 will fail with 'no handler for file extension'.
04Undo
✓No undo needed — this command does not change persistent state.
05Sources
- sox(1) — Linux man pageEvidence: Full sox man page: 'SoX - Sound eXchange, the Swiss Army knife of audio manipulation' covering format conversion, -C compression, and the gain effect with -n normalize option.
Last verified: 2026-09-17 · Category: Media