Step-by-Step Guide for Windows and macOS
Start Here (Common Audio Issues in REAPER)
If you’re here to fix a specific problem, you don’t need to read everything in order. Start with the issue that matches what you’re experiencing:
- No sound in REAPER → see REAPER Has Input But No Sound — Quick Fix Guide
- Audio device not showing → see REAPER Audio Device Not Showing (Fix Guide)
- High latency or delay → see Buffer Size & Latency in REAPER
- Crackles, dropouts, or performance issues → see Understanding REAPER CPU Performance
If you’re setting things up from scratch, follow the step-by-step guide below.
In this guide:
• Set up your audio interface correctly
• Fix no sound issues
• Configure inputs and outputs
• Reduce latency for recording
If you’re completely new to REAPER, start here: REAPER Beginner Hub.
If REAPER isn’t detecting your audio interface, or you’re getting no sound at all, the issue is almost always in the audio device settings.
This guide shows you exactly how to set up your audio interface in REAPER step-by-step, including the correct driver selection (ASIO on Windows, CoreAudio on Mac), input/output configuration, and how to fix the most common problems quickly.
Quick Setup (TL;DR)
To set up an audio interface in REAPER:
- Go to Options → Preferences → Audio → Device
- Select ASIO (Windows) or CoreAudio (Mac)
- Choose your interface driver
- Enable inputs and outputs
- Set buffer size
Common Audio Interface Problems in REAPER
If your setup isn’t working, it’s usually one of these:
• No sound in REAPER → wrong driver selected (see: REAPER has input but no sound)
• Inputs not showing → input range not enabled
• Interface not listed → driver not installed correctly
• High latency or delay → buffer size too high
Each of these is explained in the steps below.
Step 1: Install the Correct Audio Driver
Before you even open REAPER, the stability of your system depends on the correct audio driver. This step is different depending on your operating system.
A. Windows Users: ASIO is Mandatory
The ASIO (Audio Stream Input/Output) protocol is what allows your computer to communicate directly with your audio hardware with lightning speed, bypassing the standard Windows audio layer that introduces high latency (delay). This is non-negotiable for serious recording on Windows.
- Check Your Interface: Note the make and model of your audio interface (e.g., Focusrite Scarlett, PreSonus Studio).
- Download the Official ASIO Driver: Go directly to the manufacturer’s website (e.g., Focusrite, Behringer, Universal Audio) and download the latest official ASIO driver for your specific model and operating system. Do not use ASIO4ALL unless your device has absolutely no official driver.
- Install & Restart: Install the driver package and, crucially, restart your computer. This step often solves 90% of “REAPER no sound” issues for Windows users.
Troubleshooting Tip: If REAPER suddenly stops recognizing your interface or if you encounter persistent glitches, manually reinstalling the manufacturer’s latest driver is the best way to resolve these deep-seated ASIO conflicts.
B. macOS Users: CoreAudio is Built-In
macOS uses its native CoreAudio system, which is inherently low-latency and extremely stable.
- No Driver Installation Needed: Most modern audio interfaces are class-compliant on Mac, meaning they don’t require a separate driver installation. Just plug it in.
- Rare Exceptions: Some complex, high-channel count interfaces (like certain RME or Universal Audio models) may require a supplemental software package. Check your manufacturer’s website if you experience issues.
Step 2: Open REAPER Audio Device Settings
Once your interface is connected and the appropriate drivers are installed, it’s time to tell REAPER where to find your device.
- Open REAPER.
- Navigate to the menu bar at the top of the screen: Options → Preferences… (or press the shortcut CTRL+P on Windows / CMD+, on Mac).
- In the left-hand menu of the Preferences window, scroll down to the Audio section (it will be near the top) and click on Device.
Step 3: Select the Correct Audio System (ASIO/CoreAudio)
This is the most critical setting, directing REAPER to the correct driver protocol.
Windows (ASIO, WASAPI, DirectSound)
| Option | Ideal For | Latency/Performance |
|---|---|---|
| ASIO | Professional Recording (Recommended) | Lowest latency. The industry standard for dedicated audio interfaces. |
| WASAPI | System Devices/Internal Sound | Good low-latency performance when set to WASAPI Exclusive mode. |
| DirectSound | Legacy/General Use | Highest latency. Avoid this for any serious recording or mixing. |
Action: If you have an audio interface, choose ASIO from the Audio System dropdown menu. In the ASIO Driver dropdown, select the name of your specific audio interface (e.g., “Focusrite USB ASIO”).
macOS (CoreAudio)
| Option | Ideal For | Latency/Performance |
|---|---|---|
| CoreAudio | All Mac Recording (Recommended) | Low and stable latency. This is the native Mac audio protocol. |
Action: Choose CoreAudio from the Audio System dropdown menu. In the Input Device and Output Device dropdowns, select the name of your specific audio interface.
Step 4: Enable Inputs and Outputs
REAPER requires you to manually define which of your interface’s inputs and outputs you want to use. This fixes the common issue of “REAPER can’t find my inputs.”
- Input Range:
- Set First Input to the lowest input number on your device (usually 1).
- Set Last Input to the highest input number you plan to use (e.g., if you have an 8-input interface, set it to 8).
- Output Range:
- Set First Output and Last Output to the channels where your main speakers are connected (usually 1 and 2, corresponding to the Left and Right output jacks on your interface).
- Click Apply and then OK.
Quick Test
This test confirms REAPER can hear your input device:
- Create a new track (CTRL+T or CMD+T).
- Locate the circle to the left of your track title box (when you hover over it a tooltip will pop up saying Record Arm/Disarm) on the track control panel and click it.
- Click the track’s Input dropdown menu (it usually says Input: Mono) and follow the path: Input —> Mono —> Input 1 (or whichever physical input your microphone/instrument is plugged into).
- If your setup is correct, you should see the meter on the track reacting to any sound you send to Input 1!
Step 5: Set Buffer Size for Low Latency
Once audio is flowing, the next big task is balancing performance and latency. You control the latency (delay) by adjusting the buffer size.
Adjusting the Buffer
- Go to Options —> Preferences… —> Audio —> Device.
Windows (ASIO)
- Locate the ASIO Configuration button (it might be labeled “ASIO Config” or “Control Panel”).
- Click this button to open your audio interface manufacturer’s control panel (this opens an external window).
- Inside this external panel, find the setting for Buffer Size or Sample Buffer and adjust the size (in samples) using the table below as a guide.
macOS (CoreAudio)
- Find the setting labeled Request Block Size directly within the REAPER Preferences window.
- Adjust the sample value here, using the table below as a guide.
If you want a deeper explanation of how buffer size affects performance and latency, see: Buffer Size and Latency in REAPER.
The Buffer Size Trade-Off
| Buffer Setting | Latency (Delay) | CPU Load | Best Use Case |
|---|---|---|---|
| Low (64 to 128 samples) | Very Low | High | Tracking/Recording vocals and instruments (you need instant feedback). |
| High (512 to 1024 samples) | High | Low | Mixing/Editing with many plugins and effects (latency doesn’t matter, stability does). |
Workflow Tip: Always use the lowest stable buffer size for recording. Once recording is finished, raise the buffer size to reduce CPU strain while mixing. If you’re experiencing performance issues beyond buffer size, see: Understanding REAPER CPU Performance.
Troubleshooting Checklist
| Problem | Potential Fix |
|---|---|
| Interface not listed (Windows) | Reinstall the official ASIO driver from your manufacturer’s website and restart your computer. |
| Clicks, Pops, and Dropouts | Increase the buffer size in the configuration panel. Close unnecessary background programs. |
| I can hear sound, but the track won’t record. | Ensure you have Record Armed the track and correctly set the Input —> Mono —> Input X. Also, ensure Record Monitoring is set to a mode other than “Off” (right-click the Record Arm button). |
| Interface not listed (macOS) | Check Audio MIDI Setup (built-in Mac application, found in Utilities folder) to ensure the device is recognized by the OS. Restart your Mac. |
Frequently Asked Questions
Why is there no sound in REAPER?
This is usually caused by the wrong audio driver being selected or inputs and outputs not being enabled correctly.
Should I use ASIO or WASAPI in REAPER?
ASIO is recommended for dedicated audio interfaces on Windows because it provides the lowest latency and best performance.
What buffer size should I use in REAPER?
Use 64–128 samples for recording (low latency) and 512–1024 samples for mixing (better stability).
Why is my audio interface not showing in REAPER?
This is usually due to missing or incorrectly installed drivers. Reinstalling the official driver from the manufacturer often fixes the issue.
Final Thoughts
Setting up your audio interface is often the biggest hurdle for new REAPER users, but once you’ve correctly identified and selected the right driver (ASIO for Windows, CoreAudio for Mac), the hard work is over. The secret to a successful session is managing your buffer size: low buffer size for low latency tracking, and high buffer size for mixing. With these fundamentals locked down, you’re ready to start capturing high-quality audio with rock-solid stability. If you’re completely new to REAPER, you may also find this helpful: Getting Started with REAPER (Part 1).
I’d Love to Hear Your Thoughts…
Did you run into any unique problems setting up your specific interface? What’s the lowest stable latency you’ve been able to achieve in REAPER? Drop a comment below and share your experience and any troubleshooting tips you have for other REAPER enthusiasts!