Merge mono audio files into one multichannel file, step by step

1. Import

Bring in up to twelve mono WAV, AIFF, MP3, M4A/AAC, FLAC, OGG or Opus files that belong to the same take.

• Drop all the mono files of one take together; they appear as a channel list in load order.
• The tool checks sample rate, bit depth and duration and flags exactly what does not match.
• The first file sets the output defaults; other sample rates are resampled and shorter channels are padded with silence, so correct unintended mismatches first.
• Keep one take per merge. Mixing takes produces an interleaved file with no meaning.

Tip Files should start together. A shorter stem is padded with silence at the end, but padding cannot correct a track that starts late.

2. Settings

Channel order and level are the two decisions that matter.

• Drag rows to set channel 1, 2, 3 and so on, matching the routing chart of the destination session.
• Rename each channel; the names are written into the metadata of the merged file.
• Use the gain field for a corrective trim only, typically a few dB, not for mixing.
• Set the output name to the take name so the poly file matches the sound report.

3. Export and ZIP

A merge produces one interleaved file, so no ZIP is needed.

• Choose WAV or AIFF for a discrete multichannel export, then keep the source sample rate and bit depth when no conversion is needed.
• Press export; the interleaved multichannel file downloads directly. MP3 is also available, but it folds files wider than stereo down to two channels.
• Merging several takes in a row produces one file per take, each named after its output name.
• Store the merged files next to the original stems until the session is conformed.

4. Quality control

Verify the channel map before anyone syncs to it.

• Reopen the merged file in the splitter or the player and confirm the channel order you set.
• Solo each channel and check it is the microphone the name claims.
• Compare the duration with the source stems, they must be identical to the sample.
• Confirm the channel count in the Audio Inspector matches the number of files you merged.