5 min read
How to merge mono WAV files into one multichannel file
Interleaving mono files back into one poly file is the reverse of a split, and just as lossless, as long as the parameters match.
Merging takes several mono WAV files and writes them as channels of a single file. It is what you do to rebuild a poly master, to make a stereo pair from two mono recordings, or to hand a sound editor one file instead of twelve.
What has to match
- Sample rate: all sources at the same rate, or resample first.
- Bit depth: mismatches force a conversion, so pick the target consciously.
- Length: shorter files are padded to the longest, which is fine for takes that share timecode.
Channel order matters
Order the inputs the way the destination expects. For a stereo pair that is L then R. For a 5.1 bed the common film order is L, R, C, LFE, Ls, Rs. Getting it wrong is not audible until someone downmixes and the centre disappears.
Set levels before you merge
Per track gain is the reason merging is not a pure copy. A lav six decibels hotter than the boom can be trimmed at merge time so the resulting file is usable straight away, rather than passed on with a note.
Name the channels
Track names written into the merged file carry through to any tool that reads iXML, which means the file explains itself when it is split again downstream.
Doing it in the browser
The merge tool here accepts up to twelve mono files, lets you rename and trim each one, and writes a single multichannel WAV locally.