Workflow guide | 8 min read
How to Extract Stereo L/R and Center from Multichannel WAV Files
Need the stereo Left/Right pair and the Center channel of a set of multichannel WAV files as separate files? Batch LRC Splitter extracts both from each file in one batch, keeping the source sample rate, bit depth and timecode.
recording.wav → recording_LR.wav (stereo L + R) + recording_C.wav (mono C)
This is channel extraction, not a downmix: the channels are copied as recorded and nothing is mixed together.
Open Batch LRC Splitter →How to Split LCR / LRC WAV Files into Stereo and Center
Watch the tutorial to see how to process multiple three-track WAV files, extract the stereo Left/Right pair and save the Center channel as a separate mono file.
Video tutorial
Open Batch LRC Splitter →What the tool does
A multichannel WAV file stores its channels one after another, but the order is not universal: one file may be L R C, another L C R, another a 5.1 layout. Batch LRC Splitter picks the channels by their role, not their position, and writes two files:
| Output | Channels | Contents |
|---|---|---|
_LR.wav | 2 (stereo) | Left, then Right |
_C.wav | 1 (mono) | Center |
Any other channels, such as LFE or surrounds, are not written to either file. If you need a different selection or order, the Channel Mapper lets you rebuild one file channel by channel.
How Left, Right and Center are identified
The tool reads the roles from the file's own metadata, in this order:
- the WAV channel mask, only when it describes exactly as many channels as the file has,
- explicit iXML track names such as L, R and C,
- bext track names (sTRK lines), only when the file has no iXML track names.
It never guesses from the channel count. A 3-channel file with no usable metadata is not assumed to be L R C: it waits for you to say which channel is which. When the channel mask and the track names describe different roles, the file is flagged with a metadata conflict and also waits for your confirmation, with both versions shown.
How to extract L/R and Center from multiple files
The steps below follow Batch LRC Splitter as it works today.
1. Open Batch LRC Splitter
Open Batch LRC Splitter. It is a Batch Processing tool, available with Lifetime Pro, and there is no separate single-file version: to process one file, add just that file.
2. Add your multichannel WAV files
Drop WAV files with 3 or more channels, or add more later. PCM (8, 16, 24 and 32-bit) and floating-point (32 and 64-bit) WAV are supported. Only the file headers are read at this stage, so even long recordings are analysed quickly. A file with fewer than 3 channels is marked Not supported, and the rest of the queue is unaffected.
3. Review the detected channel roles
Each file shows the role found for every channel, where it came from (channel mask, iXML track name or bext track name) and how reliable it is. A file whose Left, Right and Center are each identified exactly once from reliable metadata, with no conflict, is marked Ready (from metadata).
4. Confirm the mapping when asked
Any other file is marked Needs confirmation, with the reason: no usable metadata, a missing or duplicated role, or a mask and track names that disagree. Choose its Left, Right and Center channels from the three menus and click Confirm mapping; the three must be different channels. The file then shows Ready (mapping confirmed). Each file is confirmed on its own.
5. Choose where the files go, then run the batch
In browsers that support it (Chrome and Edge on desktop), you can choose an output folder and each file is written there as soon as it is ready; existing files are never overwritten. Otherwise each file is downloaded as soon as it is ready. Files are processed one after another, and you can cancel the current file.
6. Check the LR and C files
Each source gives a stereo
_LR.wavand a mono_C.wav. If a file fails, the others carry on, and a retry writes only the output that is still missing. Open a couple of results in the Audio Inspector to confirm channel count, sample rate and metadata before handing them on.
What happens to the audio and metadata
The samples of each chosen channel are copied byte for byte. There is no summing, no gain change, no resampling and no dither, and the sample rate and bit depth stay those of the source.
| Metadata | In _LR.wav and _C.wav |
|---|---|
| BWF time reference (timecode start) | Unchanged, identical in both files |
| BWF coding history | Kept, with one line added describing the extraction |
| iXML track list | Rebuilt per file: L and R in _LR.wav, C in _C.wav, with matching count and numbering |
| bext track names (sTRK) | Kept only for the channels in that file, renumbered; names contradicting the role are removed |
| Nuendo speaker-layout field (iXML) | Removed, since it described the source layout |
| iXML project, scene, take and other fields; INFO, XMP, ID3 | Carried over |
| Standard speaker layout (channel mask) | Not written: outputs use a plain stereo or mono header |
Not every chunk written by every recorder or DAW is carried over, so keep your source files. Background on these fields is in BWF metadata explained.
When to use Batch LRC Splitter
- pulling a stereo ambience pair and a Center microphone out of 3-channel location recordings,
- preparing L/R and Center elements as separate files for editing or sound post-production,
- giving a whole set of production WAV files the same, consistent treatment,
- separating channel groups for review or for a downstream tool that expects stereo and mono files.
It is not a general-purpose surround tool. It does not downmix, and it only works with files where Left, Right and Center can be identified, from metadata or by you. For two-channel files, use Batch Stereo to Mono; to fold surround down to stereo, use the 5.1 to stereo downmixer. For the wider picture of running jobs like this on a whole folder, see how to batch process audio files for post-production.
Are the audio files uploaded?
Your audio files are processed locally in your browser, one at a time. Only the file being extracted is held in memory; its LR and C files are saved before the next one starts.
Frequently asked questions
- What does L/R/C mean?
- Left, Right and Center: the three front channels of a layout such as LCR or the front of a 5.1 file. In a multichannel WAV each of them is a separate channel, but they are not always stored in the same order.
- What files does Batch LRC Splitter produce?
- Two WAV files per source: <name>_LR.wav, a stereo file holding Left then Right, and <name>_C.wav, a mono file holding Center. If a name is already taken, _2, _3 and so on are added so nothing is overwritten.
- How are Left, Right and Center identified?
- From the file's own metadata: the WAV channel mask when it describes exactly as many channels as the file has, then explicit iXML track names, then bext track names when there is no iXML. Channel count alone is never used: a 3-channel file is not assumed to be L R C.
- What happens if the channel assignments are ambiguous?
- The file is marked Needs confirmation and is not processed until you choose its Left, Right and Center channels. This happens when no usable metadata exists, when a role is missing or appears twice, or when the channel mask and the track names disagree. Confirming one file never changes another.
- Does extraction change the sample rate or bit depth?
- No. Each output keeps the source sample rate and bit depth, including 32-bit and 64-bit float. The samples are copied as recorded: nothing is summed, and there is no gain change, resampling or dither.
- What happens to timecode and production metadata?
- The BWF time reference is kept unchanged in both files, so _LR and _C stay in sync, and a line is added to the coding history. The iXML track list is rebuilt for each output: _LR.wav lists L and R, _C.wav lists C, and Nuendo's source speaker-layout field is removed. Other supported metadata such as iXML project, scene and take, INFO, XMP and ID3 is carried over. No standard speaker layout is written into the outputs.
- How is it different from a stereo-to-mono splitter?
- Batch Stereo to Mono turns two-channel files into two mono files. Batch LRC Splitter works on files with 3 or more channels and keeps Left and Right together as one stereo file, with Center on its own.
- Is it a surround downmixer?
- No. It extracts three channels and ignores the others, such as LFE or surrounds. To fold a 5.1 file down to stereo, use the 5.1 to stereo downmixer instead.
Extract L/R and Center in Batch
Turn a set of multichannel WAV files into stereo LR and mono C files, with the source sample rate, bit depth and timecode.
Open Batch LRC Splitter →