REAPER Audio Workflows

REAPER not detecting your microphone or interface (how to fix it)

By StudioRescue Editorial

Published September 8, 2026 · Updated September 8, 2026

Plugging in a mic or interface, hitting record, and getting a flat line with no meter movement is one of the most common first-session problems in REAPER. The good news is that it is almost never a hardware fault. REAPER is unusually flexible about audio hardware, which is powerful once it is set up and confusing on day one, because it will happily open with no input enabled and simply stay silent on the record side.

This article is about the input side: your microphone or interface not showing up, or showing up but never producing a signal. If instead REAPER plays a project and you hear nothing through your speakers, that is a playback problem with a different fix, covered in REAPER has no sound: how to fix silent playback. Here we focus on getting a signal in.

First, split the problem in two

Before changing settings, find out which of two situations you are in. It tells you where to start.

1. Let your operating system allow the microphone

Modern Windows and macOS both gate microphone access per application. If REAPER was installed and never granted access, or you clicked “Don’t Allow” the first time it asked, the mic can be plugged in and working everywhere else while REAPER sees nothing. Check this first, because no REAPER setting can override it.

• Windows 11. Go to Start → Settings → Privacy & security → Microphone. Make sure Microphone access is on, then scroll down and turn on Let desktop apps access your microphone. REAPER is a desktop app, so it is governed by that lower toggle rather than by an individual app switch.
• macOS. Go to System Settings → Privacy & Security → Microphone and switch REAPER on in the list. If REAPER is not in the list yet, quit and relaunch it and try to record once so it requests access, then check again.

2. Pick the right audio system and driver

REAPER talks to your hardware through one audio system (a driver type) at a time, chosen at the top of Options → Preferences → Audio → Device. If the wrong one is selected, or the device’s driver is not installed, your interface will not appear in the device list.

• Have an audio interface? On Windows choose ASIO, then select your interface’s own ASIO driver in the device box below. This is the lowest-latency, most reliable option when the manufacturer provides it. On a Mac choose Core Audio and pick the interface.
• Just a laptop or a USB mic? On Windows choose WASAPI and pick the USB mic or built-in input. It works well and needs no extra driver. On a Mac this is again Core Audio.
• Interface with no ASIO driver of its own? Install the manufacturer’s driver first. If there genuinely is not one, a free universal driver such as ASIO4ALL can bridge the gap, but try WASAPI first because it is simpler.

One thing that surprises beginners: REAPER uses a single audio device at a time, so a USB microphone and a separate audio interface generally cannot both be active at once. If you have both plugged in, pick the one you want to record through. If you are recording with a standalone USB mic and no interface, the USB mic with no interface setup walks through that specific signal path.

3. Enable the inputs

Even with the right device selected, REAPER will not record from inputs it has not been told to use. In Options → Preferences → Audio → Device, confirm the input range is defined and enabled. Set the first input to the lowest input number on your device, usually 1, and the last input to the highest you plan to use. On a two-input interface that is inputs 1 to 2; on an eight-input interface, 1 to 8. If the range is blank or set to zero, no channels are available to assign to a track, which looks exactly like the mic not being detected.

4. Arm the track and assign the input

This is where the signal finally reaches a track, and it is the most common place a beginner gets stuck once the device is working.

If it still shows no signal

When the device is selected, inputs are enabled, and the track is armed and assigned but the meter is still flat, work down these hardware and routing checks, which mirror REAPER’s own troubleshooting guide:

• Phantom power. A condenser mic needs 48V phantom power. Make sure the interface’s phantom power (often labeled 48V) is switched on. Dynamic mics do not need it.
• The physical connection. Reseat the XLR or USB cable, try a different cable, and try a different USB port directly on the computer rather than through a hub.
• Input gain. Turn up the gain knob on the interface for the channel the mic is on. At zero gain even a working mic reads as silence.
• The device is held by another program. ASIO and exclusive-mode WASAPI usually let only one app use the interface at a time. Close other audio software (a browser tab, Zoom, another DAW) and reselect the device.
• Sample rate. If REAPER reports it cannot open the device, set the request sample rate to 44100 or 48000, which almost every device accepts.
• The computer does not see it either. Confirm the operating system detects the device. On Windows check Sound settings and Device Manager; on a Mac check Audio MIDI Setup. If the system cannot see it, no REAPER setting will.

What this will not fix

Getting the input detected is a permission, driver, and routing fix, so it has limits worth naming up front.

• It will not repair a dead interface, faulty cable, or broken mic. If the operating system cannot see the device in any app, that is a hardware or cable fault, not a REAPER setting.
• It will not fix silent playback. If the meters move while recording but you hear nothing on your speakers, that is an output problem, covered in REAPER has no sound: how to fix silent playback.
• It will not improve how the recording sounds. Detecting the mic gets a clean signal in; tone, noise, and level are separate jobs once you are actually recording.
• It will not remove latency or monitoring delay. If the input works but your voice comes back late in the headphones, that is a buffer setting, covered in how to fix recording latency in REAPER.

If it still will not detect the mic

A reliable order to work through when there is no input:

1. Blocked by the OS? Allow desktop apps (Windows) or REAPER (macOS) to use the microphone in the system privacy settings.
2. Device not listed? Set the correct audio system in Preferences → Audio → Device, install the manufacturer driver, then reopen REAPER.
3. No channel to assign? Enable the input range (for example first input 1, last input 2).
4. Meter flat on an armed track? Assign Mono → Input 1, raise the interface gain, and switch on phantom power for a condenser mic.
5. Still nothing? Confirm the computer itself detects the device; if it does not, treat it as a cable or hardware fault.