Audio Downmixer Online

or drop files here

Reduce multichannel audio to a mono or stereo WAV using speaker-layout mixing. The browser decodes the source layout and its Web Audio speaker downmix rules combine channels. The decoded channel count is shown; codec support depends on the browser.

Inspect decoded channels

A supported source may decode into more than two channels. The file summary reports that decoded count; an unsupported surround codec may fail before any mixing can occur.

Select a smaller speaker layout

Choose one output channel for mono or two for stereo. Web Audio speaker-layout rules combine the decoded channels, rather than simply exporting only the first channel and discarding every other one.

Check dialogue and effects

Listen to center dialogue, surround ambience and low-frequency content in the result. Layout interpretation and downmix rules can affect their balance; this tool does not expose custom per-channel matrix coefficients.

Budget PCM storage

At 44.1 kHz and 16 bits, mono sample data requires 88,200 bytes per second and stereo requires 176,400. These figures describe the uncompressed download, not the size of an incoming compressed surround container.

Technical references: Web Audio API specification

Audio Downmixer FAQs

Audio Downmixer decodes and processes the selected audio in your browser. File contents are not sent to an audio-processing server; page analytics are described in the site privacy policy.
Audio Downmixer saves 16-bit PCM WAV. MP3, WAV and other browser-supported inputs are decoded first; WAV output cannot restore detail lost in a compressed source.
Open Audio Downmixer, choose your recording, adjust its settings and compare the preview before rendering a WAV download. Effect settings can be auditioned during playback.
Audio Downmixer updates the effect during playback when you adjust a control. Use A/B to compare with the source. Render download creates a separate file using the current settings; moving a slider invalidates the previous download.