Reaper Set-Up: Audio Interface, File System & More

Reaper Setup: Key Takeaways

  • Download the driver for your interface from the manufacturer's web site, and install it.
  • Set Reaper's preferences to use that driver.
  •  Record, and collect your Grammy (optional).

Reaper: What Gear Do You Need?


Virtual Instruments




Audio Interface

You don't necessarily need all of these, but this is a typical setup for an independent musician's home recording setup. You might also have additional gear, such as outboard mic preamps, outboard processors, or MIDI controllers.

Reaper & Audio Interfaces

So, you have Reaper, a computer, speakers/headphones, an audio interface, and all the microphones, stands, and cables you need. But how do you hook it up? Let's get into it!

Audio interfaces typically hook up to computers vis USB or thunderbolt. The signals go both from the interface to the computer and from the computer back to the interface. There's some software that sits in between the interface and the computer. It's called a driver.

Download Your Driver And Set Up Your Audio Interface With Reaper

Plug your interface into your computer and head to the audio interface's website and download and install the driver.

Once you install the driver software, head to Reaper preferences menu ('Ctrl/'cmd' + 'p', or Options > Preferences). Mac computers don't need all of these settings, so if you don't see some of what I have here, it's ok. Don't worry.

Reaper's Device Settings

Reaper's Device Settings

Here are the steps to set Reaper up with your audio interface . . .


Step 1 - Select 'Device' under 'Audio

It's on the left-hand side.


Step 2 - Windows Only -- Select ASIO from the drop-down

Windows uses different kinds of drivers for different purposes. Select ASIO, as that's the kind of driver you'll use.


Step 3 - Select your manufacturer's driver

If you don't see the your audio interface's manufacturer listed here, something went wrong during installation.


Step 4 - Your inputs

This list will look different depending on how many inputs your audio interface has. Mine has only two, so the first input is #1, and the last is #2 🙂 

If your interface has 8 inputs, select #1 as the first input and #8 as the last.


Step 5 - Your output range

L & R outputs should go to the left and right outputs of your audio interface, through his dropdown. If you have more outputs, you can assign them here, but it's not necessary to do that to start recording.


Step 6 - Sample rate and block size

Some audio interfaces have software that controls their sample rate and block size. But you can also set it in Reaper. The 'Request sample rate' and 'Request block size' checkboxes mean you're controlling them from within Reaper and overriding the interface's controls.

It's fine either way.

My Evo 4 Allows Control From It's Software

If your audio interface doesn't like to give up control, leave the boxes unchecked and use your interface's software. In this case, entering the numbers in Reaper will have no effect. Otherwise, you can check the boxes and set your sample rate and block size in Reaper's preferences. Either way is fine.

I record at 48 kHz, 24 bit. You can do differently, if you like. If you're not sure, 48 kHz is a good call. For your block size, it works in powers of 2. You know, 16, 32, 64, 128 and so on. The smaller the number, the faster your computer processor works, and the lower the latency (the delay added by the computer for processing audio).

But lower block size also puts more load on your computer, which can result in clicks and pops in your audio.

So, block size is a compromise between speed and audio. Run it high enough to prevent crackling sounds and low enough o that you can play your speed metal licks in sync with the music.

At 64 samples, the block size setting adds 3 - 3.5 ms of latency for me. That's equivalent to the delay from standing about a meter/yard from a speaker.

If you're doing something that doesn't require playing or singing in sync with the music, you can set the block size higher.

If You Have Problems

Sample rate mismatches can cause problems with audio. It's best to run everything at the same rate. If your interface has a sample rate control, set it for the same sample rate as Reaper.

Set your system audio to be the same as Reaper, as well.

Sound Settings

Sound Settings: Here, my windows sound settings match my Reaper settings.

Can't Play YouTube Vids?

'Allow applications to take exclusive control of this device' can be an important setting. Checked, it means that your browser or media player can take control of your audio interface. If you can't play YT videos or hear audio in another application, try this setting.

Close Audio Device When Stopped

Close Audio Device When Stopped

Another setting that might help is shown in the menu above -- 'Close audio device when stopped and application is inactive'. This will release the driver for other devices, when Reaper isn't in focus. I haven't needed it as the 'Allow applications to take exclusive control of this device' Windows setting works for me.

Now you're ready to record. Plug a mic or guitar (or a even a 'gasp' bass guitar) in and you're ready to record.

Signal Flow

Your audio interface acts as a hub, though which your audio signals flow.

The audio signal starts out with a sound source into a microphone or pickup. Then the audio interface digitizes the signal so your computer can understand it. The signal goes off to your computer and is captured by Reaper, your recording software (DAW). 

The signal heads back out to your interface, where it's converted back to an analog signal, and sent you your speakers and/or headphones for you to hear.

Signal Flow

Signal Flow Chart

So here's what you have to plug in.

  • Mics/instruments plug into the inputs of your audio interface.
  • Your audio interface plugs into your computer, via USB or Thunderbolt.
  • Your interface will have output jacks for speakers and headphones. 
Evo4 Back Connections

Evo4 Back Connections

How To Record In Reaper

  • Create a new track.
  • Record arm the track.
  • Select the correct input.
  •  Set levels.
  • Hit the gol-darn record button.

Let's look at those in a little more detail . . .

Create A New Track

There are a bunch of ways to add a new track in Reaper. The easiest is to pick an empty spot on the track control panel (TCP) or the Mixer and double-click. Boom!

Creating A New Track

Creating A New Track By Clicking On An Empty Spot In Either The Mix Window, Or The Track Control Panel

'Ctrl'/'cmd' + 't' will also get you a new track. As well selecting the 'Track' menu, then 'Insert' then 'Track'. You can also use that menu to insert multiple tracks. But double-clicking is just as fast!

Record Arm The Track

The little red button in the upper-left on your tracks, record arms the tracks. Once clicked, the button will turn bright red and the track will be ready to record.

Record Arm Button

Record Arm Button

Select The Correct Input

But before we record to that track, we need to tell it what to record. Your audio interface may have multiple inputs. How does Reaper know which input to record? Well, that input thingy!

It's called the 'Input Source' and it, erm, selects the input source. In other words, if your microphone is plugged into input number 1 on your audio interface, click the 'Input Source' and choose 'Mic | Line | Instrument 1' 

Once you've elected the correct input source, you should see your meter bouncing around a bit, if you've got something plugged into your audio interface. Let's set some levels.

Selecting Your Input

Selecting Your Input

Setting Levels

Each audio interface has a different way of setting levels. In general, you turn a knob up or down on your audio interface to get a level that's not too strong and not too weak. Sometimes it's a hardware knob, and sometimes it's a software knob. You're aiming for a level of about -18 dBFS average, and no greater than -6 dBFS at the loudest part.

Your audio interface may have metering (sometimes a light that goes from green [good] to red [bad]).

Reaper Meters

Reaper Input Meter

Reaper itself has metering. The meters here default to peak metering (dBFS), so you'll be able to see the meter readings right next to the track.


I bet you can guess which button you press to record. It's the red, record button on the transport bar, below. Go ahead. Press it. See what happens.

Reaper Transport Section

Reaper Transport Section

The transport section works much like an old-fashioned VHS that we used to use before the wheel was invented. 'Record', 'Stop', and 'Pause' do exactly what you might imagine.

If you don't see the transport bar, go to the view menu and check 'Transport'.

View Transport

View Transport Menu

File Management & Other Preferences

Out-of-the-box, Reaper's defaults aren't the most efficient for most people's workflow. Here's what you should do about it.

  • Create a temp directory and set Reaper to put all the non critical files in it.
  • Create a song projects folder and set Reaper to save all your songs in individual folders inside the song projects folder.
  • Set Reaper to create a media folder inside each song project, to keep your recordings organized.

You can do this easily in a few minutes. Here's more detail . . .

Reaper File Types

Reaper makes a few different files and file types.

  • Reaper project files: Extension .rpp. These files don't contain audio. But they contain almost everything else about your project, including where the audio files are stored. They include instructions for the edits you make, as well as which FX plugins you're using, their settings, and more.
  • Reaper backup files: Extension .rpp-bak -- these are backups for your project at various points in time. They are lifesaving if a project file becomes corrupted. 
  • Reaper undo files: Extension .rpp-undo -- these are undo files.
  •  ReaPeak files: When you record, Reaper makes a graphic representation of the waveform of what you've recorded. These waveforms are little graphics files. 
  • Audio files: When you record audio, you make audio files. You can record in WAV, AIF, MP3 (but don't), OGG, FLAC, and more. Personally, I record to WAV.

Reaper doesn't generally create MIDI files (although it can), but stores all the MIDI information in the project file, itself.

By default, Reaper dumps all these files into one big mess. But it's all changeable in preferences. Just a couple of minutes setting the file preferences up, and you'll be well-organized and ready to rock.

It makes sense to store the necessary files related to a project in a directory. I have a bunch of songs, so it makes sense for each song to have a folder, and my project and audio files in that folder.

Reaper File Structure

Reaper File Structure

I have an internal SSD drive (K), which isn't the drive that has my OS. On that drive, I have a 'Song Projects' folder. Within that folder I have individual song folders. The song folders contain the project file, undo files, and a 'Media Files' folder, which has all the audio related to that project. Simple.

The rpp-bak, rpp-undo, and ReaPeaks files are not something you need to think about much. If you accidentally delete the Reapeaks files, Reaper will just create them again when you next open the project. The backup files are only needed in an emergency. And the undo files can sit in the project directory. If you lose them, it just means you won't be able to undo your latest actions in Reaper.

I mean, you can undo them, but you can't do it by 'Ctrl'/'cmd' + 'z'. You'll have to do it manually.

So, we can dump the rpp-bak and ReaPeak files somewhere else, where they don't clutter up the project file. That will also make it easier to delete them when we're done with the project. I've created a C:/Reaper Temp directory and put them all there. Every few months I empty it out.

Here's how to set that up in preferences.

  1. 1
    Open 'Preferences' and select 'Paths'. Choose the folder where you want to store song projects (Ironically, I call mine 'Song Projects'), and set the path under 'Default path to save new projects'.
  2. 2
    Select the 'Store all peak caches (.reapeacks) in alternate path' and choose where you want to store them.
Project and ReaPeaks Paths

Project and ReaPeaks Paths

Next, let's set up your backup and undo file paths.

  1. 1
    In 'Preferences' select, 'Backups'. Check the 'Auto-save to timestamped file in additional directory'  and choose the folder where you want to store store the backups.
  2. 2
    Select the 'Save undo history (RPP-UNDO) (if enabled in general prefs) with auto-saved projects box' and choose your path.

Temp Directory

If you want to do it like Uncle Keith does, create a directory on your main drive called Reaper Temp. Under that, create two directories -- Backups, and Peaks. Choose those as your file paths for, well, you know -- backups and ReaPeaks files.

Temp File Structure

Temp File Structure

Media Directory

File > Default menu: Main file > Project settings > Menu tab. Type in the directory where you want your media files stored. I have 'Media Files' there 🙂

Media Tab Settings

Media Tab Settings

Automatic Backup

Yeah. Turn that on. You'll thank me later. Set it for how often you like. 5-10 minutes is normal. 'Auto-save to timestamped file in additional directory' is what you want.

Backup Preferences

Backup Preferences

Other Backups

I use Google Drive to back up all my important Reaper stuff. You don't have to use Drive, but you should def back up. It's not fun to lose hours, or years of work due to an inevitable hard drive failure.

I back up my song projects folder, and my Reaper preferences folder. I have it tuned off while I'm working, but at the end of the day, or if I take a break, I fire up Drive and let it back up any new or changed files.

Two backups is not a bad idea. Store copies of your song projects on an old hard drive and keep it at your weird Uncle Louie's house.

Optimizing Your Computer For Recording

Your computer might work just great for recording audio, without any changes. But computers tend to have a lot of processing going on in the background. Virus scans, file indexing programs, or calls to a network may interrupt or delay other processes going on.

For most computer tasks, that's not important. Who cares if there's a 3 ms delay between when you type "Please take me back" followed by a crying emoji, and when it shows up on the screen in your email program?

But for audio, we need a cohesive stream of uninterrupted data. It's not that much data (USB 2.0 can handle dozens of tracks coming in at once), but it's fast, and it has to come in uninterrupted, and in exactly the right order.

Reaper might work perfectly fine on your computer without any changes. But if you notice any dropouts in your recordings, or if you just want better performance, check out the following.

  • Turn off virus scans, if you can. It's annoying to be recording and have a virus program fire up for a scheduled scan in the middle of a session. For that matter, even having them active can tank your computer's performance. Disconnect your computer from the internet and turn virus protection off, to the extent you can.
  • Turn off your network connections, if you have interruptions. See if that solves the problem.
  • Turn off file indexing programs. I use a program called Everything. It's great for finding files. It's much more efficient and quick than the standard Windows file search. But it keeps track of new files by running processes in the background. I turn it off when I'm recording.
  • I use a program called Wise Game Booster (for Windows) which shuts down unnecessary processes and frees up RAM. You can use it, or a similar program to help clear out anything running in the background before you record.
  • Stop programs from starting up. Seems like everybody wants to be running when you boot up your computer. Shut them down and set them so they won't harsh your mellow by starting in the first place.
  • LatencyMon is a program for Windows (Macs don't need this) that checks suitability of a system for recording audio.  You run it for a few ours and it picks up and programs that interrupt your system and tells you about them.
  • Kill other background processes. Both Mac and PC have provisions for killing background processes. If yore having problems with audio being interrupted, open up 'Task Manager' in Windows, or 'Activity Monitor' in Mac.
  • Bluetooth can cause interruptions. Turn it off.
  • I use Google Drive to back up my song projects. But it kills my PC's performance when it's running. Turn off any backup systems you have going and turn them on when you're on a break or when you finish for the day.

Turn it back on, when you finish.

Setting Up Reaper: Conclusion

Big picture, here's the process . . .

  1. Download the manufacturer's driver for your audio interface, and install it.
  2. Set preferences in Reaper to recognize the interface.
  3. Set up file preferences in Reaper for organization.
  4. Hook everything up -- audio interface to your computer, plug speaker cables into the back and into your speakers, plug your mics in, etc.
  5. Fire up a track, record arm it, set the input and level, and go to town!


About the author

Keith Livingston

Keith Livingston started recording his own music in the late '70s, on a 4-track. He worked his way into live sound and studio work as an engineer -- mixing in arenas, working on projects in many major studios as a producer/engineer, and working in conjunction with an independent label.

He taught audio engineering at the Art Institute of Seattle, from 1990-1993, and in '96, contributing to authoring several college-level courses there.

He was General Manager of Радио один (Radio 1) in St. Petersburg, Russia.

Now he spends his time recording his own songs wherever he roams, and teaching others to do the same.

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