Chaining Effects

Effects in the effects chain are applied strictly left to right. The output of one effect becomes the input to the next.

play test.wav trim 5 10 fade q 1 0 1 norm -3
#             ──────── ──────────── ──────
#             1. trim  2. fade      3. norm

Order matters

# norm then gain: normalize to 0 dBFS, then boost 6 dB — likely clips
play test.wav norm gain 6

# gain then norm: boost first, then normalize back down — norm undoes the gain
play test.wav gain 6 norm

Neither is wrong — they just do different things. Think through the pipeline before you run it.

Writing to a file

When you’re happy with the chain, swap play for sox and add an output filename:

sox test.wav output.wav trim 5 10 fade q 1 0 1 norm -3
play output.wav

Sox converts the format and applies the effects in a single pass, so trimming and converting to MP3 is one command:

sox test.wav output.mp3 trim 0 30 norm -3
play output.mp3