Audio Forge Pro

Free Stereo to Mono Fixer & Left-Ear Audio Repair Online

A free browser-based channel fixer that repairs recordings where audio plays in one ear only, or converts stereo into a centered mono track. Fix single-mic Zoom, OBS, and Skype recordings, or downmix uneven stereo audio — all in your browser without uploading audio files.

Why Is My Audio Only Playing in the Left Ear?

When a single microphone records into a stereo track (Zoom calls, OBS, Skype, or a solo XLR interface input), the voice is written to the left channel only and the right channel stays silent. Audio Forge Pro duplicates the left channel to the right with 100% phase-aligned fidelity so the voice plays out of both ears — or merges both channels into one centered mono file.

Key Features

  • Copy Left Ear to Both: 1-click repair for single-mic Zoom, OBS, and Skype recordings where the right channel is silent.
  • Copy Right Ear to Both: Mirrors the fix for right-channel-only recordings.
  • Stereo to Mono Downmix (Center Panning): Combines left and right into one centered track with 0.5 gain attenuation to prevent clipping and phase comb filtering.
  • Folder Batch Processing: Drag in an entire folder of call or stream recordings — every file is channel-balanced automatically.
  • Zero Server Uploads: 100% private in-browser processing. Your files never leave your device.

How to Fix Single-Ear Audio

1. Drag a file or a whole folder of recordings into the drop zone (MP3, WAV, M4A, OGG, FLAC, AAC). 2. Choose "Copy Left Ear to Both" for one-ear recordings, "Copy Right Ear to Both" for the opposite case, or "Downmix L+R to Mono" for a centered mono file. 3. Process and download instantly — no DAW install, no re-export workflow.

Who Needs the Stereo to Mono Fixer?

  • Zoom & Skype Interviewers: Balance mic audio that only plays from the left headphone.
  • Podcasters with Solo XLR Interfaces: Fix recordings where a single mic is wired to input 1 of a Focusrite or Behringer interface.
  • OBS Streamers: Correct commentary recorded as stereo in Windows audio settings instead of mono.
  • Video Editors: Standardize wireless-lapel-mic camera audio before importing into Premiere Pro or CapCut.

Frequently Asked Questions

Is the Stereo to Mono Fixer completely free? Yes. Channel fixing, mono downmixing, and folder batch are free with no account, watermark, or file limits.

What is the difference between "Copy Left to Both" and "Stereo to Mono Downmixing"? "Copy Left to Both" takes the left channel sound and copies it to the right channel — ideal when the right channel is completely silent. "Downmix L+R to Mono" combines both channels into a single centered track — ideal when both channels have sound but the mix feels uneven or too wide.

Will downmixing stereo to mono degrade my audio quality? No. The downmix applies equal 0.5 gain scaling to both channels, which prevents +6 dB clipping and phase cancellation while preserving the original sample rate and frequency content.

Does my audio file get uploaded to a server? No. All channel math runs locally in your browser, and your files are never uploaded, stored, or shared.

Can I normalize loudness or remove silence after fixing channel balance? Yes — continue into the AI Silence Remover or the -14 LUFS Normalizer in the same session without re-uploading. Read the full pacing and loudness guide.