Updated by Bobby
Updated on February 10th, 2022
Updated article formatting and link to Sweetwater's product page for the iRig Pro Duo (removed previous links).
Before we get into the details and the "grit" of the iRig Pro Duo, I should point out the intention and purpose behind the design.
It's essentially a mobile recording interface, designed to work with any device.
Its claim to fame is feature-rich recording capability, packed into a small enclosure that you can take anywhere and use with almost any computer, tablet or smartphone. The unit fits nicely into any home recording situation.
Moreover, IK Multimedia has designed the Duo to record any instrument, including vocals.
Here are some of the highlight features:
- Two channels (TS or TRS)
- 24-bit recording quality
- Phantom power
- Low-noise built-in preamp
- USB, battery and DC power supply compatible
The iRig Pro Duo is a fully-functional USB recording interface, but with more compatibility options (phone, tablet, etc.), and with a much smaller and more portable enclosure, than most other, similar devices.
iRig Pro Duo Review Summary
IDEAL FOR: Home studios, live performances (adding sound effects, synth devices or recording) and on-the-go songwriting)
- Dual-channel recording
- Small and highly portable
- Gain and volume adjustments are idiot-proof
- Use direct headphone monitoring or external speakers
- Easy setup
- Pricey compared to other USB interfaces
The Physical Interface
All of the Duo's capabilities can be determined by walking through the unit's physical enclosure. This will highlight the instruments it's capable of recording, power sources and platform compatibility.
You'll find the Duo is similar in design to something like a small PreSonus Audiobox.
The best way to get a feel for the unit is the following graphic from IK Multimedia:
This graphic labels every feature of the iRig Pro Duo and helps us get a feel for its exterior interface.
Note the following, in particular:
- 2 x TRS/TS mic and instrument inputs (where you'd plug in a microphone or guitar)
- Two balanced TRS outputs (can go to external speakers or monitors)
- MIDI input and output
- Two GAIN knobs and LED indicators (one for each internal preamp)
This second graphic (below), with visual indicators, helps give you a more concrete idea of how the iRig Pro Duo is setup and where each physical connection mechanism is located.
While there might be an initial intimidation factor, if you haven't used a USB recording interface before, the Duo is incredibly easy to setup and use.
In my studio I run a Mac Mini with Amplitube 4 and GarageBand, which I used to test the unit. Hooking everything up to the Mac Mini was fairly basic and intuitive.
Once you get familiar with the inputs and how you'd like to use it, we can start to walk through the setup and connection process.
Setting Up and Using the iRig Pro Duo
Here's exactly what I had at my disposal when I tested the Duo:
- Mac Mini computer (with GarageBand)
- Mackie CR3-X3 Studio Monitors
- Amplitube 4 software
- Two Hosa Guitar cables
And to provide just a little more context, I was setting up the Duo to play guitar through a set of headphones and to do some basic recording.
I also tried it with a Warwick bass.
For whatever instrument you're using, the same process (for the most part) will still apply.
I'll take you through that process step-by-step.
Once I had the Duo unboxed and had a chance to get familiar with the interface, I went ahead and plugged my monitors into the TRS outputs on the side of the device.
Note that you can also use headphones, if you don't have external speakers.
Here's a shot of the headphones plugged in:
For most of the testing I used this set of Skull Candy headphones (pictured above), which sounded fantastic. The monitors sounded good as well, and I didn't notice a significant difference in sound quality between the two.
From there, I used the included USB cable to plug the Duo into my Mac Mini, which is class compliant (doesn't need drivers to work) and is immediately recognized by the operating system.
The last step for me was to add my guitar into the instrument jack.
It's hard to see from the photo, but I've labeled each input with its corresponding connection.
The unit is dual-channel with two separate preamps and gain control wheels for each input, meaning you could feasibly run two instruments or microphones (or one of each) at one time, with independent gain control for each one.
For my purposes, I only used one channel.
Getting everything hooked up and ready to use only took a few minutes, while the power source came through my computer via the USB connection.
Once you've gotten to this point, the next step is to make sure the Duo is communicating with the recording or processing software on your computer. I'll use Amplitube 4 to illustrate this process.
Connecting the iRig Pro Duo to Recording Software
Keep in mind, the Duo is likely compatible with any recording software on your computer.
In addition to Amplitube 4 and GarageBand, the following applications will also work in much the same way:
- FL Studio
- Amplitube Lite (iPad and iPhone version)
- GarageBand for iPhone and iPad
Since the Duo is class compliant (and particularly friendly with Apple products) almost all recording applications can be engaged (assuming a functional USB connection) by simply selecting the Duo as the default recording source.
My example is with Amplitube, but it'll be pretty much the same process with all other recording apps.
Setting up the iRig Pro Duo to work with Amplitube 4
Start AmpliTube 4 on your Mac or PC.
The app will show a screen with an amplifier model displayed, the default "AmpliTube" brand. Just for a little variety, I went ahead and switched that out for a Fender Vibro-King amp model.
You can use the AmpliTube Custom Shop (which installs with AmpliTube 4) to experiment with whatever amps you'd like to try out.
AmpliTube lets you use them 72 hours for free.
Here's what the app's interface looks like:
Once you've chosen an amp model, we need to be sure the program is setup to listen to input (your guitar's signal) from the iRig Pro Duo.
To do this, go to "Settings" for AmpliTube 4 and click "Audio MIDI Setup:"
In the following window, make sure that the input and output devices are both set to the iRig PRO DUO option. This should be available via the drop down menu on each item.
Once this is set click OK and you should be able to hear your guitar, or other instrument, coming through the amp model.
You should also notice the green signal indicators bouncing up and down, as you play. If they're red, your signal is clipping which means volume will have to be lowered, either on your guitar (or amp) or at one of the mixing points in the application.
You might have to tinker with volume for awhile to get everything right, but it's fairly intuitive and easy to use (more on this later).
Setting up the iRig Pro Duo to work with Audacity
In addition to being an amp modeler and effects processor, AmpliTube also provides recording capabilities.
I'd like to highlight how you can use Audacity (which is an open source program) to record quickly, as a simpler alternative to AmpliTube 4, since those of you who aren't guitar players don't need the amp or effects processing features.
Assuming you've connected everything the same as before, you'll need to first download Audacity for your Mac (or PC), install and run the program.
In the application, the only thing you'll need to change is the recording input device (has the microphone icon next to it):
Make sure that it's set to "iRig PRO DUO". If you want to hear your computer sounds through your headphones or monitor (perhaps if you're playing a song off your computer), make sure you change the output (listed below as "Core Audio") to the iRig Pro Duo as well.
Once this is done you're ready to record in Audacity, just like you would in the AmpliTube software.
Again, most recording software can be setup in the same manner. Just look for these same settings ,which will usually be labeled with one of the following terms:
- Audio Setup
- Recording Source
Ease of Use
While software can be a bit unpredictable, I can say that during the time I spent testing the Duo, I had zero compatibility issues and devoted no time at all to troubleshooting.
Everything just worked.
Out of the box, I was playing through my guitar and bass and tinkering with sounds quickly. Gain and volume adjustments took a little time, but this was mostly related to complexities within the Mac and software, having little to do with the Duo itself.
Volume and gain within the Duo
There are only two mixing adjustments you need to worry about with the Duo, while everything else related to volume i/o can be handled either by the guitar or by the software itself.
Those two adjustments are the following:
- Gain levels for each preamp (one for each channel)
- Monitor volume wheel for your headphone jack (direct monitor)
In my opinion, this is one major advantage that the Duo has over other USB audio interfaces.
Many of them just have a lot of controls and knobs to learn, which do provide more functionality, but at the same time can be more than you need, and can over-complicate the process.
The iRig Pro Duo makes it significantly easier to concentrate volume issues and fix them from either your guitar (or other input source) or the software itself.
The Portability Factor
The portability of the Duo is certainly a nice bonus, though I found that to be a feature that intrigued me far less than advertised.
Then again, I usually don't record outside of my home studio.
However, I can see how those who are on the go a lot would use the iRig Pro Duo heavily, as a means of logging ideas quickly into their phone or tablet.
The context in which you play, record and perform will determine how much the portability factor will matter to you.
Final Thoughts and Takeaways
Even if it didn't have small size and portability going for it, the iRig Pro Duo is a fully functional USB audio interface that is more compatible and (at the same time) simpler than many in a similar price range.
Portable or not, it's a great studio solution and a wonderful tool to have as a live performer.
You'll benefit from the simplicity, the ability to use more devices (phone, tablet, etc.) and the super-quick setup.
It's definitely a new favorite for me in the studio.
- The iRig Pro Duo, while portable, isn't exclusively for those on-the-go (can hold its own in all recording environments)
- Sound quality is mostly dependent on other gear (microphones, guitars, studio monitors, etc.)
- Gain and volume controls are refreshingly simple
- iOS and Android compatibility helps set the Duo apart from other USB interfaces
- Headphone monitor has zero latency and sounds fantastic (at least with a pair of Skull Candy headphones)
- Unit runs off of batteries, USB power (when connected to a Mac or PC) or a DC adapter (included)
Other iRig Pro Duo Resources
If you're looking for other resources for the iRig Pro Duo, we've linked to the most important and notable ones here, included the product home page and official PDF manual.