5 May 2026 | 5 min read
Splitting a stereo file into two mono files, and when you should
Half the stereo files on a shoot are not stereo at all. They are two unrelated mono sources sharing a container.
On set, a two channel WAV is very often boom on the left and a radio mic on the right. It is stereo in the file header only. Treating it as a stereo image means panning a lav hard right and a boom hard left, which is exactly what nobody wants.
Three cases, three treatments
- True stereo: a matched pair such as an MS or XY ambience. Keep it stereo.
- Dual source: boom left, lav right. Split into two named mono files.
- Dual mono: both channels identical. Keep one, discard the other.
How to tell which one you have
Solo each side and listen. If the content differs, it is a dual source file. If they are identical, it is dual mono, usually from a phone or a camera. If they share content with subtle timing and level differences, it is a genuine stereo pair.
Splitting without damage
A correct split deinterleaves the channels and writes each one as its own file at the original sample rate and bit depth. No summing, no gain change, no resampling. Name the outputs after the source, for example TAKE12_BOOM and TAKE12_LAV, so the assistant editor does not have to guess.
Do it in the browser
The splitter here handles two channel files exactly the same way it handles an eight channel poly WAV: it reads any track names stored in the file, lets you rename each output, previews them in the player, and exports a ZIP. Everything runs locally.