Podcast and Spoken-Word Audio
How to record a Zoom or phone interview into REAPER (when the guest cannot record their end)
Published October 24, 2026
If your guest cannot record themselves, the goal is still two separate tracks: your microphone recorded cleanly in REAPER, and the guest as call audio on a track of its own. The easiest way to get the guest separated is Zoom's own Record separate participant audio files option. If you want the call inside REAPER instead, Windows can capture it with REAPER's WASAPI loopback mode or an interface with a loopback feature, and a Mac needs a virtual audio device such as the free BlackHole driver. Whatever route you pick, the guest will still sound like a call. You are keeping the damage on one track, not removing it.
The best way to record a remote interview is a double-ender, where each person records their own microphone locally and you line the files up afterwards. That is covered in how to record a double-ender so the tracks do not drift. This article is for when that is not happening: the guest is on a work laptop they cannot install anything on, they are calling from a phone, or they simply will not do it.
In that case you are recording the call. You can still do it well. The mistake to avoid is recording one mixed file with both voices in it, because then your clean voice and their compressed voice are welded together and you cannot fix either without affecting the other.
What you are actually aiming for
Two tracks, kept apart from the start:
- Track 1: you. Your microphone, recorded directly in REAPER from your interface or USB mic. This track never goes through the internet, so it can sound as good as your normal recordings.
- Track 2: the guest. Whatever arrives through the call. This is compressed by the call software and limited by the guest's microphone and connection. It will not match track 1, and that is fine.
With them separate you can clean, level and EQ the guest without touching your own voice, cut crosstalk, and line up loudness between the two. That later work is covered in how to fix a remote guest's bad audio in REAPER and how to match host and guest loudness.
Route 1: let Zoom separate the voices for you
If the interview is on Zoom, check this before building any routing. Zoom's desktop app documents an advanced recording option called Record separate participant audio files, found under Settings › Recording › Advanced. Zoom says it records separate audio files for up to 80 participants, so you can edit or filter one person's audio on its own.
Turn the option on before the call
It is part of the desktop app's local recording settings. Check the setting the day before rather than during the interview, because an account administrator can limit recording options.
Record your own mic in REAPER at the same time
Arm a track in REAPER on your microphone input and record the whole session there as well. That gives you a clean local copy of your voice regardless of what Zoom does with it. Before the real interview, confirm that Zoom can still use your microphone while REAPER has the interface open. Some audio drivers share a device between programs happily and some do not.
Clap or count in at the start and the end
You now have files from two different programs. A clear sound at the start lets you line them up, and a second one at the end tells you whether they drifted apart over the hour.
Import the guest file into REAPER
After the call, drag the guest's file onto its own track under your REAPER recording and align the start markers.
People who join by phone are not separated: Zoom says the audio of users who joined by phone is merged into one audio file. And the guest's separate file is still the audio that came through the call, so it is separated, not improved.
Other call and recording platforms have their own versions of this feature. Look for wording like “separate tracks” or “per-participant audio” in that platform's own help pages before you build anything yourself.
Route 2 on Windows: capture the call inside REAPER
If you want the call on a REAPER track directly, Windows gives you two broad options.
REAPER's WASAPI loopback mode
The official REAPER User Guide has a section called Recording Live Windows Output. In short: enable Allow feedback routing on the Advanced page of Project Settings, choose WASAPI as the audio system in Options › Preferences › Audio › Device, and select Shared loopback mode. The guide says your block size and sample rate need to match the sound device as set in the Windows Control Panel. Then add a track, set its input to stereo, arm it, mute the track's output, and record.
Take the guide's own warnings seriously. It says feedback routing is not recommended for beginners and that inappropriate use can damage your hearing, your equipment or both. Muting the recording track's output is what stops the captured audio from feeding back into itself. Start with your volume low.
There is a practical catch for interviews. This mode records whatever Windows is playing, which means system notification sounds land on the guest track too. It is also built around capturing Windows output, so plan on recording your own microphone separately rather than assuming the same device setup will give you both. Silence notifications before you start, and test with a short call.
An interface with a loopback feature, or a virtual audio cable
Many audio interfaces include a loopback or software mixer feature that sends computer playback back to the computer as an extra input, and virtual audio cable drivers do a similar job in software. The details are manufacturer-specific, so use your interface's own manual rather than a generic tutorial. The goal is the same: your mic on one input, the call playback on a different input, each recorded to its own REAPER track.
Route 2 on a Mac: a virtual audio device
On a Mac, the usual way to get another app's audio into REAPER is a virtual audio device. A widely used free option is BlackHole, an open-source virtual loopback driver from Existential Audio that passes audio between apps. The outline:
Send Zoom's output to BlackHole and your headphones
In Audio MIDI Setup, create a Multi-Output Device that includes your headphone output and BlackHole, then choose it as Zoom's speaker. You keep hearing the guest, and the same audio is also available to REAPER. Follow BlackHole's own Multi-Output instructions for this, including its FAQ note on which output must be enabled and listed first.
Combine your interface and BlackHole for REAPER
REAPER records from one input device at a time, so create an Aggregate Device in Audio MIDI Setup that includes your interface and BlackHole. Apple's instructions say to pick the device with the most reliable clock as the clock source, and to turn on Drift Correction for every device that is not the clock source. Choose your interface as the clock source.
Two tracks in REAPER
Select the Aggregate Device in REAPER's audio device settings. Set track 1's input to your microphone channel and track 2's input to the BlackHole channels, arm both, and leave monitoring off on the guest track so you are not hearing the guest twice.
Stopping echo on either system
Echo on a call recording usually means the guest's voice got back into your microphone or back into the call. Three habits prevent most of it:
- Wear headphones. If the guest plays out of your speakers, your microphone records them a second time, slightly late, on your clean track.
- Give the call software your microphone, not REAPER's output. If REAPER's master output is routed into the call, the guest can end up hearing themselves.
- Do not monitor the guest track through REAPER when you can already hear the guest through the call. Hearing both is confusing and can create a loop.
Phone guests
A guest on an ordinary phone line is the lowest-quality case. A traditional phone call carries only a narrow band of the voice, roughly 300 Hz to 3.4 kHz, which is why phone audio sounds thin and boxed in. No plugin puts back what the line never carried.
If the guest can join a video-call app from their phone instead of dialling a number, ask them to. If they dial in, expect phone quality, and remember that Zoom merges dial-in participants into one file rather than separating them.
Recording laws differ between places. Some require only one person on the call to agree; others require everyone to agree, and a call between two locations can be covered by both sets of rules. The Digital Media Law Project's practical advice is to tell the other person you intend to record, get their agreement, then ask them to confirm it once the recording is running. This is general information, not legal advice.
What this will not do
- It will not make the guest sound like they are in the room. Call audio is compressed, and the guest's laptop mic and room are still on the recording.
- It will not undo the call software's own noise suppression or echo cancellation. If the guest's words are getting chopped, that damage happens before the audio reaches you. See what can and cannot be fixed when noise suppression was on.
- It will not fix a dropped connection. A glitch or gap in the call is in the recording too.
- It will not replace a double-ender. If the guest can record their own end, even on a phone voice memo app, that file will almost always beat the call audio.
| Situation | Best available route | What you will get for the guest |
|---|---|---|
| Guest can record locally | Double-ender | Their real microphone quality |
| Zoom call, guest on a computer or app | Zoom separate participant audio files, plus your mic in REAPER | Call quality, on its own file |
| Want the call inside REAPER on Windows | WASAPI shared loopback, or interface loopback | Call quality, plus any system sounds |
| Want the call inside REAPER on a Mac | BlackHole plus an Aggregate Device | Call quality, on its own track |
| Guest dials in by phone | Any of the above | Narrow phone-band audio |
Run one test call first
Every route here depends on your specific computer, interface and call app, so do a five-minute test with a friend before the real interview. Record, stop, and play both tracks back. Check that your voice is on track 1 only, the guest is on track 2 only, nothing echoes, and no notification sounds got in. Fixing routing in a test costs five minutes. Finding out after a one-hour interview costs the interview.
When a guest cannot record their own end, keep the two voices on separate tracks from the start. Use Zoom's separate participant audio files if you are on Zoom, record your own mic in REAPER either way, and use WASAPI loopback or an interface loopback on Windows, or BlackHole on a Mac, if you want the call inside REAPER. Expect call quality for the guest, clap at the start and end, and test before the real thing.
Sources
- Zoom Support, “Changing settings in the Zoom Workplace desktop and mobile app” - Recording tab, Advanced: Record separate participant audio files (up to 80 participants; phone participants merged into one file). support.zoom.com
- Cockos, REAPER User Guide v7.81 (September 2026), section 3.44 “Recording Live Windows Output” - Allow feedback routing, WASAPI shared loopback mode, block size and sample rate matching, beginner and hearing warnings. Current release checked on the day of publication: REAPER 7.82. reaper.fm/userguide
- Existential Audio, BlackHole - open-source (GPL-3.0) macOS virtual audio loopback driver; Multi-Output Device setup and FAQ. github.com/ExistentialAudio/BlackHole
- Apple Support, “Create an Aggregate Device to combine multiple audio devices” - Audio MIDI Setup steps, clock source and Drift Correction. support.apple.com
- Digital Media Law Project, “Practical Tips for Recording Phone Calls, Conversations, Meetings, and Hearings” - one-party and all-party consent, interstate calls, recording consent on the record. The site notes it is no longer updated. dmlp.org