A página sox
diz:
channels CHANNELS
Invoke a simple algorithm to change the number of channels in the audio signal to the given number CHANNELS: mixing if decreasing the number of channels or duplicating if increasing the number of channels.
The channels effect is invoked automatically if SoX's
-c
option specifies a number of channels that is different to that of the input file(s).
Portanto, não é equivalente ( channels
em vez de remix
), mas o resultado é o mesmo.