Why convert to mono at all
File size is the usual reason: mono at the same bitrate is effectively double the quality per channel, or half the size at the same quality. For speech that is a straight win, since a voice recorded on one microphone has no stereo information to lose.
Playback safety is the other. Phone speakers, smart speakers and many laptops are mono, and they sum the channels themselves. If your mix has phase problems, that summing can make parts of it vanish — converting deliberately lets you hear that before your listeners do.
One interview microphone on each channel
A common recording setup puts one speaker on the left channel and the other on the right. Splitting into two files gives you each voice separately, which makes editing and levelling far easier than working on the mixed version.
The side channel is not a vocal remover
Subtracting right from left cancels everything panned dead centre — usually the lead vocal, bass and kick. It works, crudely, and it also destroys the bass and leaves behind ghostly artefacts wherever the mix is not perfectly symmetrical.
Real vocal separation uses trained models that understand what a voice is. This is a phase trick from the 1970s. It is worth knowing about, and it is worth knowing its limits.
Frequently asked questions
Does averaging the channels lose quality?
It loses the stereo image — that is the point. It can also lose specific sounds if the two channels are out of phase, which is exactly the problem worth discovering deliberately rather than by accident.
Is my audio uploaded?
No. The channels are combined locally — the file never leaves your device.
Something wrong with this tool, or an idea for it? Tell us