Mobile rigs have gained quite a bit of traction. It isn’t uncommon these days for music producers/podcasters to use an iPhone or an iPad as their main recording unit. You’ll find mobile versions of almost all popular DAWs such as Garageband, Logic Pro, FL Studio, Ableton, and Pro Tools available on iOS. In an effort to match the recording experience, most audio interface manufacturers have started providing full support for iOS devices.
When choosing an iPhone audio interface, the first thing you should consider is compatibility. While there is a surge in class-compliant interfaces, a lot of the older models don’t support iOS. The ones that claim to do so are not always properly optimized for iPhones. There’s a lot of ambiguity and people get easily discouraged. The safest bet is to go for interfaces that have actually been tested with an iPhone. That way you know you’re going to get something that is guaranteed to work without any issues.
Power consumption is also an important factor. If an interface is bus-powered (Solely Powered through USB) you need to make sure your iPhone can drive it. iPhones can’t power an audio interface if the interface doesn’t feature an external power source. And since most iOS devices feature a lightning port, you’ll also need a Lightning to USB Camera adapter which you can then connect to a powered USB Hub.
Keep in mind that the size of your unit really matters, especially if you’re planning to travel with your interface. This might seem like a trifling metric, but you really don’t want to be moving around with a heavy unit, especially if you only want to use the interface for audio playback.
Finally, make sure that your interface is durable and has good build quality. You want to get something that lasts you for a bit. The good thing is that most modern interfaces are meant to last, provided that you take care good care of them. If you’re not moving around then that’s not an issue but if you have somewhat of a mobile rig then you may want to pay special attention to how well the unit has been put together.
The Audient Evo 4 is a compact 2×2 USB audio interface that produces amazing audio considering its price point. It is a class compliant interface that features a maximum 96kHz sample rate and a 24 bit depth.
The Evo 4 has a very intuitive and extremely beginner-friendly design. The back panel features 2 TRS/XLR jack inputs, 2 balanced line outputs and a USB-C port that doubles as the unit’s power supply. On the other side, the front panel contains a dedicated JFET instrument input and a ¼’’ headphone output socket.
The main panel of the Evo 4 contains all of the unit’s controls, along with a halo LED meter. The largest control on this panel is a touch sensitive dial which can be used to control I/O levels. You can dictate what functionality the dial performs by toggling any of the buttons which let you alternate between adjusting output levels, channel 1 and 2 input gain, and output audio source. You will also find a 48V phantom power button and an auto gain feature button on that same panel.
Physically speaking, the Evo 4 is extremely compact and light, which makes it excellent for on-the-go purposes. It has a very simplistic yet elegant design which we thought really highlights its user friendliness. The large dial is exceptionally satisfying to use especially when combined with the responsive LED halo. However, we did feel that Audient compromised a bit on durability because of the unit’s flimsy plastic build.
For such a small box, the Evo 4 is packed with incredibly powerful components and has a ton of different functionalities. For starters, the unit’s mic pres offer a 58 dB gain range which is remarkable considering its price tag. We tried recording with some of the most gain-hungry mics (Shure SM7B and the Heil PR40), as expected, the Evo 4 was able to effectively drive them while maintaining an extremely transparent signal throughout. The best part? we didn’t have to manually set the gain settings since toggling the auto gain feature automatically sets the optimal gain levels for any mic/instrument you want to hook up. We also noticed that the Evo 4 has one of the flattest frequency response curves (0.1 dB deviation) which is remarkable.
The unit also has powerful AD and DA converters that provide an incredible 113dB of dynamic range. For playback purposes, this is more than enough to reproduce unscathed signals from your PC’s audio stream. Recorded tracks sounded extremely granular and detailed when transmitted through studio monitors.
Audient has been around for more than 2 decades. Their products have always been great and the Evo is no different! Prior to its release, Audient had great success with their budget-friendly iD interfaces (they have a large following in the audio interface market). The Evo line consists of the Evo 4, Evo 8, and the Evo 16. The main difference between the 3 models lies in their number of I/Os. The Evo 8 has 2 extra line outputs, 2 extra XLR/TRS mic inputs, and 1 additional headphone socket. The Evo 16 features 2 headphone sockets, 8 input channels, and 8 output channels in addition to ADAT I/O. However, all 3 units contain the same components, similar controls, and produce the same sound quality.
There is no denying that the Evo 4 provides amazing performance considering its inexpensive price. However, we believe that the product could’ve been improved in some ways. For instance, the unit’s gain, sampling rate, buffer settings reset whenever we reboot the device. This issue can be especially frustrating for those who have to frequently move around.
Additionally, the unit features a dedicated headphone socket, however, the volume controls are poorly designed. If you have both monitor and headphones connected to your device, the Evo will playback via both simultaneously, with no practical option for muting a single channel. You’ll have to physically untether either your monitors or your speakers to prevent a channel from playing audio.
Overall, the Evo 4 is an extremely powerful audio interface that performs exceptionally well considering its price. It is an extremely beginner-friendly unit that contains advanced tools such as the auto gain feature and the gesture-controlled knob. The Evo 4 is easily one of the best portable class-compliant audio interfaces we’ve tested. That is why we recommend it as a risk-free purchase that can provide full return on your investment.
The Evo 4 has an auto gain feature which means that you don’t have to manually set the gain levels.
The unit’s preamps offer a lot of headroom.
The Evo 4 has a remarkably flat frequency response.
You can easily travel with the Evo 4 because of how small and light it is.
The unit’s converters are extremely powerful.
The unit is made of flimsy plastic.
You can’t control the headphone output level separately.
The unit’s settings reset whenever rebooted.
The Motu M2 is a powerful class compliant audio interface that has 2 ins and 2 outs. It is a compact unit that features a maximum 192kHz sample rate and a 24 bit depth.
On the front side, you’ll find 2 Line/XLR jack inputs that each have a MON button, gain knob, and 48V power toggle. You can monitor these inputs through a full-color LED display that provides an accurate metering of their levels. Next to it is a large monitor knob, a ¼’’ headphone socket and its dedicated volume controller.
The back panel of the Motu features MIDI I/O socket, 2 balanced monitor outputs and 2 unbalanced ones. It also contains a power button, a kingston lock socket, and a USB-C port which is also the unit’s sole power supplier.
The M2 is a small and lightweight unit that is perfect for traveling purposes. It’s fully enclosed in rugged metal, it can take a bit of a beating. The unit has a beginner friendly UI and the hardware controls are well-spaced which facilitates the fine-tuning process.
The Motu M2 has some of the best specifications we’ve seen on a mid-range audio interface. The converters offer a dynamic range of 115 dB which is one of the highest measurements we’ve had. This means that they can capture audio with impeccable detail with almost zero noise. Additionally, the M2 has a relatively flat frequency response in the audible 20Hz-20kHz range. As a result, everything recorded is reproduced with extreme accuracy.
Using the Shure SM57, we were able to record some professional quality tracks which sounded clean and vibrant. We were mainly using a 96kHz sample rate and 64 buffer speed and didn’t face any noticeable delays. However, since the unit only provides 50dB of gain, we had to crank the gain knob all the way up to get decent results. Nonetheless, our recordings were crystal clear and pristine. The unit’s preamps also feature remarkably low THD+N which means that the audio doesn’t clip/distort even at high gain levels.
As far as compatibility is concerned, we ran most of our tests on an iPhone device with no compliance issues. We were easily exporting our recordings into the IOS version of GarageBand after only wiring both units through a camera lightning to USB adapter and a USB powered Hub. However, we noticed that during M2’s boot up phase, any recording would sound extremely distorted. Even though this issue only occurs on iPhone, it still ceases once the M2 fully-boots.
One thing that shouldn’t go unnoticed with the M2 is its loopback connectivity feature. This feature allows you to easily run live streaming/podcasting setups through your device and gives you the option to merge your PC’s audio stream with your input source.
The M-series includes 2 different models which are the Motu M2 and the M4. While both units have the same build quality, design and components, the M4 features extra I/O channels. You’ll find 2 additional line inputs, 2 balanced line outputs, and 2 unbalanced line outputs. Moreover, the M4 features an input monitor mix knob unlike the M2. Otherwise, both units utilize the same drivers, offer the same specification, and work perfectly fine on IOS devices.
The Motu M2 is one of the most well-polished devices we’ve tested. However, while it doesn’t have any major performance issues, we still picked up on some of its flaws. For instance, the M2 would exhibit strange behavior once phantom power is activated. To be more specific, the unit produces an audible low frequency noise when hooked up to a dynamic mic. However, this issue isn’t a concern with condenser mics since they draw phantom power, so make sure to toggle off 48V if you want to connect a dynamic mic.
Moreover, you won’t be able to operate the M2 on an iPhone unless you install a firmware update which can only be done through Mac/PC. Nevertheless, this firmware update will prevent any instability issues or random audio clicks/pops.
Overall, the Motu M2 offers amazing sound quality for a mid-range audio interface. With the M2, you get a remarkably flat frequency response, an incredibly low THD+N, and a ton of dynamic range. The unit is also one of the few audio interfaces that work on iPhone devices with no notable issues. That’s why if you’re looking for an inexpensive audio interface that will allow you to record professional grade tracks on your iPhone, we recommend that you go for the M2.
MOTU M2 Benefits
The Motu M2 offers an incredible dynamic range of 115dB.
The unit has a very flat frequency response which corresponds to extreme accuracy.
The M2 works with all devices including iPhone.
The preamps have a very low THD+N (Total Harmonic distortion and noise).
You can podcast/live-stream with the Motu M2 because of its loopback connectivity feature.
MOTU M2 Drawbacks
You will hear an audible low frequency noise if you record with a dynamic mic while phantom power is active.
The device requires a firmware update to be used which you can only install through mac/PC.
The audio will be extremely distorted during the bootup on iPhone devices.
The iK multimedia iRig Quattro is an incredibly versatile audio interface that is specifically tailored towards mobile users. It is a small unit that features 4 inputs and 2 outputs.
Because space is at premium with the iRig Quattro, you’ll find controls/sockets on all 6 panels. On the side panels, you’ll find 4 XLR/TRS combo jack inputs, 2 unbalanced line inputs, a ⅛’’ input socket, and 2 phantom power toggles for channels 1-2 and 3-4. You’ll also find 2 XLR outputs, a ⅛’’ stereo output, ⅛’’ MIDI I/O sockets, and a ⅛’’ headphone jack.
The back panel contains a battery compartment in case you want to use the unit in standalone mode. You can alternate between battery and USB power through a switch on the unit’s front side panel. That same panel contains the USB-C port, a 9V external power socket, and a MIDI host socket.
On the main panel, you’ll find 4 separate gain knobs, a headphone output volume controller, a volume encoder for the line outputs, and a large metering screen that indicates battery life, gain level, and phantom power state. You’ll also find 5 functionality switches that activate direct monitoring, loopback connectivity, audio limiting, stereo mode, and the built-in microphone.
Build wise, the iRig Quattro has a very compact form which makes it ideal for portability purposes. The unit is enclosed in a durable high quality plastic and the knobs are quite satisfying to use.
Unlike most interfaces, the Quattro works right out of the box, so we didn’t have to install any firmware/driver updates. The device is also class-complaint which means that it works with any device including iPhones. Our experience using the Quattro with an iPhone was overall smooth and effortless. We were able to send and receive tracks through the iPhone version of FL studio without facing any major latency/software issues.
In terms of sound quality, the Quattro is equipped with respectable components. The AD and DA converters offer a dynamic range of 103dBA which means that they can capture audio with a fair amount of detail. They can also process audio at a maximum sample rate of 96kHz and 24 bit-depth. To test them, we hooked up an electric guitar and set our sample rate to 96kHZ with a 248 buffer speed. The round-trip latency was discernible yet very small. However, the tracks were clean, noise-free, and didn’t contain any unwanted artifacts.
The unit’s microphone preamps offer around 54dB of gain range which is more than enough to drive any mic. We tested them with a Sennheiser MK 4 which produced transparent and noise free audio. We then gradually increased the gain setting to reach a point where audio starts to distort. Once the LED display indicated Clipping, we used the limiter switch which immediately reduced the gain by -12dB and prevented further distortion.
Even though iRig Quattro is overall well-made and doesn’t have any major performance issues, we still think that it could improve in certain aspects. For instance, the Quattro is considerably more expensive than units with comparable sound quality even if it has a lot more features. Moreover, the unit has quite a displeasing design and it lacks any touch of modernism.
Compared to the iRig Duo, the iRig Quattro underwent major improvements both performance wise and in terms of sound quality. For instance, the Duo can only sample audio at a 44kHz sample rate and the converters offer less dynamic range. Additionally, the Quattro is equipped with slightly cleaner and more powerful preamps, even though both offer a similar gain range.
Most importantly, the DUO only features 2 inputs instead of 4 and it doesn’t contain a USB socket, so you can only connect it to your phone through MIDI. The Quattro also features additional functionalities like audio limiting, direct monitoring, and a built-in mic. However, both units are compatible with iPhone devices.
Overall, the iRig Quattro is an extremely versatile unit that works incredibly well with iPhone devices. Even though sound quality isn’t the Quattro’s strongest suite, it still emerges as one of the most adaptable interfaces in the market. With the Quattro, you’ll get a ton of power options and a lot of hardware controls that are packed into a compact and lightweight unit. That’s why if you’re looking for a powerful portable audio interface to use with your iPhone, we recommend you pick the iRig Quattro.
The Quattro provides good sound quality.
You can power it through 3 different options.
The unit has a lot of hardware controls which are great for live performance.
You can use the Quattro with any mobile device including iPhone devices.
The Quattro is compact, light, and features a standalone mode which makes it great for on-the-go purposes.
The Quattro is a bit expensive.
The unit has an unpleasant design.
According to the scoring model, there is only a 0.3 point variance between the highest and the lowest average scores. The competition was pretty close across all categories. If you analyze the chart further, you will find the highest variance in the Sound Quality and Additional features categories. The iRig Quattro comes out on top when it comes to Additional Features, yet it scores the lowest in Sound Quality where the M2 prevails. Meanwhile, the Evo 4 exhibits a stable behavior scoring 8 in 4 out of 5 categories.
The Motu M2 remains consistent throughout as it doesn’t score below 7.5 in any given category. The unit even scores the highest (9.5) in Sound quality which is arguably the most important category. On the other hand, the M2 loses out in the input/output category because the iRig Quattro offers more I/O channels comparatively. However, unless you want to record a full band, the 2 inputs and 2 outputs that the M2 provides are enough for most purposes, especially if you are using an iPhone!
We would like to mention that the iRig Quattro rivals the M2 with an average score variance of only 0.1. The Quattro also scores the highest in both the Input/Output and Additional features categories which is a testimony for its versatility. The unit is the only one to offer multiple power options including battery power which can be incredibly useful for portability purposes. While the Quattro does come at a hefty price, it still provides a lot of value because of its incredible features. In terms of versatility and portability, the Quattro is undoubtedly the best of the bunch.
However, when it comes to the overall best iPhone audio interface, the M2 emerges as the clear winner. Leading with an overall score of 8.2, the unit displays remarkable capability in all 5 categories. With an exceptionally low noise-floor, incredibly powerful converters, and extremely useful additional features, the M2 has everything you need to record great tracks. The unit is fully compatible with iPhone, so you won’t face any driver or latency issues. We recommend the M2 as an extremely price efficient audio interface that you can’t go wrong with!
In most cases, you can find this information on the audio interface’s product page. However, not all audio interfaces that claim compatibility are actually optimized with IOS devices. The best approach is to find user-tested product reviews either through YouTube videos or trusted audio blogs.
Most iPhones feature a lightning port which means that you will need a lightning to USB camera adapter in order to connect both devices (A Lightning-to-USB cable doesn’t work). Moreover, If an audio interface is exclusively powered through USB, your iPhone won’t have enough power to drive the interface. In that case, you will have to buy an additional powered USB hub which you can then use to power your interface.
The main thing you should look out for when choosing an iPhone audio interface is device compatibility. Audio interfaces that are fully compatible with iPhones are hard to come by. You can find a lot of audio interfaces that work with iPhones, however, most of them are either plagued with driver issues or are extremely unstable. Some newer audio interface models also have features/controls that can be exclusively accessed through a PC/Mac software. For that reason, you need to make sure that your interface has sufficient hardware controls or at least supports a basic IOS version of its control software.
Other than the issues of connectivity and power consumption which can be easily resolved, you won’t find any major limitations when using an audio interface with an iPhone. However, if you’re planning to export and edit tracks on an IOS DAW, you will probably have access to less controls, but you can still perform basic tasks. You will also have to figure out how to change sampling rate and buffer speed settings through the DAW.