Podcast and Spoken-Word Audio
How to fix a podcast recorded in mono or on one channel in REAPER
Published September 11, 2026
If your podcast only plays in one ear, one voice was recorded onto a single channel, almost always because a mono mic was captured on a stereo track. The recording is fine, it is just parked on one side. In REAPER, double-click the item to open Item Properties and set Take channel mode to Mono (Left) or Mono (Right), whichever side has the voice, and it will play centered in both speakers. A true mono recording that plays evenly in both ears is not a problem and needs no fix.
“My podcast only comes out of one ear” is one of the most common panics after a first recording, and the good news is that the audio is almost never damaged. Nothing was lost. The voice was simply recorded onto one channel of a two-channel (stereo) item, so it plays hard to one side instead of down the middle. This is a routing and file problem, not a performance or gear failure, and it takes about ten seconds to fix once you know where to look.
Before you change anything, it helps to be clear about what “mono” actually means, because the word gets used for two different situations that need different responses.
Mono is not the same as one channel
People say “it recorded in mono” to describe two very different things:
- A true mono recording is a single-channel file. One voice, one channel. REAPER plays it out of both speakers equally, so it sounds centered. For a solo podcast or a single voice, this is correct and ideal. It is not something to fix.
- A one-channel recording inside a stereo file is a two-channel item where the voice sits only on the left (or only on the right) and the other channel is silent. That is what makes it play in one ear. This is the thing you fix.
So the real question is not “is it mono” but “is the voice stuck on one side of a stereo file.” If a solo episode plays evenly in both ears, leave it alone even if it is technically mono. If it plays in one ear, read on.
Why it happens
The usual cause is a mismatch between a mono microphone and a stereo track input. A single mic produces one channel of audio. If the track was armed to record a stereo input, REAPER captures two channels and puts your mic on the first one (the left), leaving the second (the right) empty. Play that back and the voice is only in the left ear.
A few specific ways beginners land here:
- Recording a single USB mic or interface input while the track input was set to a stereo pair instead of a single mono input.
- Recording two people into one interface and ending up with host on the left and guest on the right of a single item, when you actually wanted them mixed or on separate tracks.
- Importing a file that a phone, recorder, or another app already saved as a one-sided stereo file.
Test it first so you fix the right thing
Look at the waveform
A one-channel-in-stereo item shows a visible wave on one lane and a flat line on the other. That flat lane is your empty channel.
Watch the track meter
Play the item and watch the track’s stereo meter. If only one side moves, the audio is on a single channel.
Decide what you have
One voice on one side is a simple channel fix. Two different voices on the two sides is a split job, covered further down.
Sometimes both channels hold the exact same voice. To check, click the Mono button on the master, then invert the polarity of one channel. If the sound disappears completely, the two channels are identical and you can safely treat the file as mono.
Fix one voice stuck on one side
This is the most common case and the fastest to fix. It is non-destructive, so it changes playback without altering the original file.
Open Item Properties
Double-click the audio item (or right-click it and choose Item properties). The dialog includes a Take channel mode selector.
Pick the side with the voice
Set channel mode to Mono (Left) if the wave is on the left, or Mono (Right) if it is on the right. REAPER now plays that single channel centered in both speakers.
Check the level
If you are not sure which side has the voice, Mono (Downmix) combines both channels into one. It works when the other channel is silent, but glance at the meter afterward and use Mono (Left) or Mono (Right) if the level looks off.
That is the whole fix for a solo recording. The voice now sits in the middle where it belongs, and you never touched the source file.
Fix two people split across the two channels
If a two-person recording landed with one host on the left and the other on the right of a single item, you usually want them on separate tracks so you can level and clean each voice on its own. REAPER can split the channels for you.
Right-click the item and choose Item processing, then Explode multichannel audio or MIDI items to new one-channel items. REAPER creates a new mono item per channel, each centered, so you can treat the two voices as independent tracks. From there you can balance them, which is its own small task covered in how to match podcast host and guest loudness in REAPER.
Only split when the two sides really are two different voices. If both channels carry the same person, splitting just gives you two copies of one voice. Do the mono-button test above first.
Stop it happening next time
The permanent fix is at record time, not after. In REAPER you do not choose a mono or stereo track, you choose a mono or stereo input. Arm the track, click the input (record) button, and select a single mono input that matches the physical jack your mic is plugged into, for example Mono then Input 1, rather than a stereo pair like Input 1/2.
For an interview, record one mono track per microphone: mic one to Input 1, mic two to Input 2, each on its own mono track. That keeps both voices centered and separately editable from the start. The full setup is in how to record two people in one REAPER session, and the whole beginner workflow is in how to record a podcast in REAPER. If REAPER is not seeing your mic as an input at all, that is a different problem covered in REAPER not detecting your microphone or interface.
| Symptom | Likely cause | Test | Fix |
|---|---|---|---|
| Plays only in one ear | Mono mic recorded onto a stereo track | One waveform lane flat, one meter side still | Take channel mode Mono (Left) or Mono (Right) |
| Two voices, one in each ear | Two mics captured as one stereo item | Both lanes have different waveforms | Item processing › Explode to one-channel items |
| Solo voice, centered, technically mono | Single mono file, working as intended | Even level in both ears | Nothing, it is fine |
Save the corrected version
Changing the channel mode fixes playback inside your project, but the original file on disk is unchanged. Once the voice is centered, render or export to create a corrected file to share. A single voice can be exported as mono without any downside. The steps are in how to export audio from REAPER.
What this will not do
- It will not recover audio that was never recorded. If a channel is truly silent, there is no hidden signal on it. A guest whose mic never reached REAPER cannot be pulled out of an empty channel.
- It will not make a single-mic recording “stereo.” One voice is a mono source; centering it is the correct result, not a limitation.
- It will not fix room noise, echo, or an uneven performance. Those are separate cleanup steps and are unrelated to which channel the voice sits on.
In almost every one-ear case the recording is completely intact and the fix takes seconds. The rare exception is when a second voice or a whole take was never captured, in which case no setting can bring back audio that does not exist.
A podcast that plays in one ear is a voice parked on a single channel of a stereo file, not a damaged recording. Set the item’s Take channel mode to the side with the voice, or explode two voices into separate mono items, then re-export. Prevent it next time by arming a mono input per mic. True mono that plays evenly in both ears needs no fix at all.
Sources
- Cockos, REAPER User Guide (current version 7.79, released August 17, 2026) - take Channel mode options (Normal, Mono downmix, Mono left, Mono right), track record-input selection (mono versus stereo inputs), and Item processing to explode multichannel audio into one-channel items. reaper.fm/userguide
- The REAPER Blog, “Working with split stereo audio in REAPER” - using the master Mono button and a polarity null test to tell a true stereo pair from duplicated mono. reaper.blog
- Why Reaper, “Creating Individual Tracks out of Multichannel Interleaved Files” - exploding an interleaved multichannel item into separate mono items. whyreaper.com
- Audio University, “Microphone Only Recording To One Side? Here’s How To Fix It” - why a mono mic recorded on a stereo track lands on a single channel. audiouniversityonline.com