AUDIO TOOL KIT

6 min read

How to split a poly WAV file into mono tracks, step by step

Eight channels in one file, and post wants eight files. Here is how to deinterleave a poly WAV correctly, without resampling and without losing track names.

Splitting a poly WAV is a deinterleaving job. The samples for every channel sit side by side inside one data chunk, and the split simply writes each channel out as its own file. Done properly it is lossless: the output is the same samples, in the same order, at the same rate.

Before you split, read the file

Open the file in an inspector first and note the channel count, sample rate, bit depth and the track names stored in the iXML or bext chunk. If a tool cannot show you those, it probably will not preserve them either.

The steps

  • Drop the poly WAV into the splitter. Channels, rate, depth and duration are detected on load.
  • Check the track names it read from the metadata: Boom, Lav1, Lav2, Plant, Mix L, Mix R.
  • Rename anything the recorder got wrong, or that your delivery spec names differently.
  • Untick channels you do not need, such as an unused input or a redundant mix track.
  • Export. One channel gives a single WAV, several give a ZIP with one mono file per track.

What must not change

Sample rate and bit depth stay as recorded. A 48 kHz 24 bit poly file produces 48 kHz 24 bit mono files, so the durations match to the sample and the stems drop into the timeline in sync with the picture.

Naming that survives the handover

Use the take name as a stem and the track name as a suffix: A001_T003_Boom.wav, A001_T003_Lav1.wav. An assistant editor can then import a folder and read what each file is without auditioning any of it.

Doing it locally

The splitter on this site runs in the browser. Nothing is uploaded, which is the only workable answer when the rushes are under embargo or the interview is confidential.

Frequently asked questions

Does splitting a poly WAV lose quality?
No, provided the tool keeps the original sample rate and bit depth. The audio data is copied, not re-encoded.
How many channels can be split at once?
Up to 32 channels here, which covers every common field recorder including 16 track bags.
Will the mono files keep timecode?
The start timecode from the bext chunk is carried over, so the stems still line up on the timeline.

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