USB-C audio interfaces are by far the most popular in the market. They’re more progressive units which succeeded the once established USB-B port standard in audio interfaces. Almost all newly released interfaces feature a USB-C port, however the connection itself has no impact on performance. It is instead an agreed upon convention since newer technology is moving towards USB-C ports.
USB-C offers some extra perks which include bi-directional charging. This means that you can have a double-end USB-C cable and either ends can be connected to both the host or the receiver. While, the port type doesn’t really speak to the unit’s transmission speed, it instead determines how fast the connection is, and can hence drastically affect latency.
A USB 2.0 port (480 Mbs/s) is much slower than an advanced USB 3.2 port which can deliver up to 20 gigabytes per second. In most cases this means that you’ll have less latency using an interface with a version 3.0 USB-B compared to a version 2.0 USB-C interface. However, there are interfaces with a USB 2.0 port that outperform several USB 3.0 interfaces in terms of latency.
When choosing a USB-C audio interface, you should focus on getting the basics right before nitpicking on extra features. Your most important criteria should be finding an interface with enough I/O channels to house all your synths/instruments/mics. As a general approach, try to find a unit with more input channels than you initially need so you’ll have room for future expansion (two to four inputs is the minimum). That way you won’t have to buy a separate unit when you purchase additional gear.
Sound quality is one of the most important aspects when choosing an audio interface. You want transparent preamps that can drive any input without generating noise. You should also look for powerful converters that can retain a lot of details whether from your PC audio stream or input channels.
Depending on your use case, you may also consider more advanced features on your interface. For instance, If you’re planning on live-streaming or podcasting, then you want loopback connectivity and some additional hardware controls. On the other hand, an onboard DSP can be extremely valuable if you want to record while running several heavy plugins. There’s also ADAT/SPDIF for future expansion.
Nonetheless, try to not exceed your budget by going for excessive features that you might not need. Instead, focus on more premium converters and preamps because those are what make the most difference!
Best USB-C Audio Interface Reviews
Universal Audio Apollo Twin X DUO Heritage Edition
The UA Apollo Twin X Duo Heritage Edition is a high-end USB-C audio interface that features 10 ins and 6 outs. It’s a relatively compact unit that’s used by a lot of professional audio engineers.
On its backside, you’ll find most of your ports which include: 4 TRS line outputs, an optical input port, and 2 TRS/XLR combo inputs. You’ll also find a power switch, a 12V external power port, and a USB-C socket which features TB3 capability. On the other side, the front panel features a dedicated instrument input socket and a ¼’’ headphone output jack.
The main panel of the Twin X Duo contains most of its controls. Its main component is the large dial which can be used for different functions such as controlling gain levels, headphone output levels, etc. The dial sits between a bunch of LED meters which you can use to gauge your mic in gain levels, line gain levels, and monitor output levels. Below this knob, you’ll find 8 buttons that can be used to toggle different features like Phantom power, Pad, Dim, Mute, Talkback and stereo. In addition to the monitor and input buttons which you can use to cycle through the channel allocated to the gain knob.
In terms of build-quality, the Twin X Duo is very durable and quite hefty considering its compact form. We also like its minimalistic design which highlights its functionalities without over cramming the panels with redundant controls.
As for its sound quality, the Twin X Duo is equipped with some of the most powerful components in the market. For starters, it features 2 incredibly powerful UNISON preamps that allow you to emulate some of the most popular preamps such as Neve, Manley and Helios.
To test the unit out, we hooked up an MXL V250 condenser mic then started gradually increasing its gain level. Sure enough, the DUO produced zero noise throughout and gave us a lot of gain to play with. Even at very high levels, we didn’t lose the slightest on sound quality nor did we run into any sort of unexpected behavior.
To access the UAD plugins, we launched UA’s extremely intuitive software which gives your control over EQ, Compressors, Emulators, and other plugins. We then chose to run a NEVE preamp plugin because of our prior experience using a NEVE 1073. We were impressed by how accurate the emulation was. It is more or less an exact replica of the actual thing down to the smallest detail, with very subtle difference that will not be visible to the untrained ear. The two additional DSP cores had the unit running at zero latency throughout.
The Twin X DUO features a maximum sample rate of 192kHz which can be partly attributed to its incredibly powerful converters. Those converters provide a remarkable 127 dB of dynamic range which translates to extremely detailed and pristine audio. Our unit was capturing our mic recordings with extreme clarity and incredible vividness without forgoing any detail in the process. It even handled running on a 192kHz sample rate and a 32 buffer speed with almost no latency.
While we did enjoy using the Twin X DUO we can’t say that it’s all round perfect. For instance, even though we had no issues using the UA software on Windows, we can’t say the same about its setup. We had to spend some time installing and uninstalling obscure driver packages trying to get our DUO to work, because the official drivers didn’t work on our unit. However, we didn’t face any such issues on mac where the drivers were well optimized.
Additionally, after some recording sessions, the TWIN X DUO can sometimes become incredibly hot (more than 100 degrees F). The metallic design doesn’t help either because you can literally burn your fingers if you touch the panels. If you’re recording back to back, it would be a good idea to install some sort of external cooling system to combat this issue.
The Twin X DUO was released alongside 2 different models which are the SOLO and the QUAD. The main difference between the QUAD and the DUO is their DSP power where the number of each model actually corresponds to the number of Sharc chips each unit contains. The SOLO however also has less I/O channels and a completely different design. Albeit, all units are equipped with the same components and have fairly similar performance otherwise.
Overall, the Twin X DUO is a professional level audio interface that is one of the most powerful in the market. With its UNISON preamps, incredible converters, and remarkably low latency, the DUO emerges as an all inclusive, powerful unit. We highly recommend the DUO if you’re looking for a USB-C interface to supplement your production skills.
Twin X DUO Benefits
It features 2 Extremely powerful and quiet UNISON preamps.
Its converters are very detailed and accurate.
The unit has amazing built quality
The DUO has incredibly low latency because of its built-in DSP and TB3 technology.
You get access to UAD plugins.
Twin X DUO Drawbacks
Its official Windows drivers might not work.
The unit can get extremely hot, so you might need an external cooling system.
The SSL2+ is one of the most popular mid-level USB-C audio interfaces in the market. It is a 2×4 interface that features a 192kHz sample rate and a 24 bit depth.
On its back panel, you’ll find all of its ports which include an MIDI I/O port, 2 XLR/line combo inputs, 2 balanced Monitor outputs, and 2 Unbalanced RCA outputs. You’ll also find the USB-C port which is used to power the unit (USB Bus-Powered).
The main panel of the SSL2+ features separate controls for both input channels which include a gain knob, a 48V button, a Hi-Z toggle, a line button, and a legacy 4K mode switch. You can also monitor the gain levels for each input using the 5-level LED meters (10 dB sensitivity).
Additionally, the panel features a large blue monitor dial that can be used to control the output volume. Next to it are 2 headphones volume encoders labeled Phones A and Phones B and a monitor mix which allows you to dial between your PC’s audio stream and the input channels. There is also a stereo button next to the monitor mix and a button labeled 3 and 4 next to the Phones B knob which lets you indicate which headphone mix is being affected by it.
Buildwise, the SSL2+ has a relatively compact tabletop form. There isn’t really anything special about its design, but it’s enclosed in a durable material nonetheless. The unit’s controls are well-spaced and its knobs have quite a nice feel to them, but we would’ve preferred if they were a bit larger so that we’d have a much easier time dealing with precise values.
As for sound quality, the SSL2+ is equipped with 2 powerful preamps that provide a 62 dB of gain range with a 130.5 dBu. This means that the SSL2+ can drive almost any instrument/microphone. For starters, we tried recording using a Shure SM7B which resulted in pristine and very clean output. We then hooked up a guitar to the 2nd channel which the SSL2+ also handled extremely well.
The SSL2+ features the 4k Legacy mode which is an emulation of SSL’s 4k series. Toggling this effect produced a slight enhancement in harmonic distortion and a small boost to the high-end. It worked especially well when we tried recording vocals using condenser mics like an AT2020 because of the warmth it adds. However, while it is a nice addition, we can achieve the same effects in a DAW so it’s really more of a marketable feature.
The headphone amps on the SSL2+ are fairly powerful and provide enough amplification to drive most headphones. For referencing, we used an AT MX40 and an AKG K271 which we only had to keep at 50% volume. We did however have to crank the volume up to 80-90% when using a pair of high impedance DT 990s (250Ω), but the output was otherwise solid and clear. Having 2 headphone channels is also extremely useful in cases where you want to have a 2nd person listen through.
While we believe that the SSL2+ is an overall well-polished unit, it does have some drawbacks. For example, we don’t think that the gain meters have any practical use because of their extremely low measurement sensitivity. Intervals of 10 dB are simply too big for you to gauge any proper information about your inputs. Additionally, our unit’s buttons aren’t properly fitted so they have a bit of wobble to them. Our 4k button even fell off at some point and we had to manually place it back in its socket. However, everything else about its build quality seems great.
When SSL announced their first series of mid range audio interfaces, they dropped both the SSL2+ model and the SSL2 model simultaneously. The SSL2 is a cheaper model which contains the same preamps, converters, headphone amps, and circuitry as the SSL2+. Both units also have the exact same design and build quality. The only difference between both models however is their number of I/Os. Unlike the SSL2+, the SSL2 features a single headphone output, no MIDI connectors, and doesn’t have any unbalanced outputs. Otherwise, both units sound the same and contain the same features.
Overall, we believe that the SSL2+ is one of the best audio interfaces competing in the mid range market. It’s a relatively small unit that is packed with powerful converters, preamps, headphone amps, and boasts an incredibly small latency. We definitely recommend the SSL2+ as a risk-free purchase that you can’t go wrong with.
The SSL2+ contains transparent preamps that provide a lot of headroom.
You can monitor through 2 different headphones.
It features a built-in 4k legacy emulator which adds some pleasant effects to your recordings.
The headphone amps can power almost any microphone.
It has a compact form, perfect for traveling purposes.
The gain meters are useless because the levels are too far apart.
The buttons are wobbly and poorly fitted.
The Motu M4 is one of the most praised mid-level audio interfaces by pro and home producers alike because of how much it offers for its rather inexpensive price. It’s a powerful USB-C audio interface that features 4 input and 4 output channels.
Its backside contains most of its I/O ports which consist of: 2 TRS line inputs, MIDI I/O sockets, 4 balanced line outputs, and 4 RCA (unbalanced) line outputs. It also features the power switch and a USB-C socket which doubles as the unit’s sole power source.
On the front panel, you’ll find a ¼’’ headphone jack and its corresponding volume controller. You’ll also find 2 Line/XLR combo input jacks each with its own 48V toggle, gain dial, and MON button. Moreover, this panel contains a large monitor knob, a full-color LCD metering screen, and a monitor mix knob which you can use to select output audio sources.
Physically speaking, the Motu M4 has a very compact form which is perfect for traveling purposes. It is enclosed in a high quality black metal so it can take a bit of a beating. However, it is still relatively light and can be held with a single hand.
The Motu M4 is one of the only audio interfaces in its price range that features a Full color LCD display. We expected it to be more of a gimmicky tool, but it turned out to be functional and extremely detailed. It indicates gain and output level with incredible precision even though we noticed that it has a slight delay.
As for its sound quality, the M4 is equipped with some high fidelity converters that can capture audio with extreme detail and precision. They can process audio at a maximum sampling rate of 192kHz and a 24 bit depth. When recording through the M4, we set the sampling rate to 192kHz and chose the lowest buffer speed. These settings would usually overwhelm most interfaces, and you’d normally get some pops and cracks. However, the M4 reliably produced artifact free tracks with no noticeable latency. Even for basic audio playback purposes, the M4 was extremely granular mainly because of the powerful DAC.
As for its preamps, they’re fairly powerful, transparent and provide a lot of headroom. We were able to drive most dynamic and condenser mics and the output was transparent and artifact-free throughout. The unit can also handle high impedance headphones such as the DT990 which we only had to keep at 50-60% volume during mixing. We did however feel like the M4 added some sharpness at higher volume levels, but we don’t think you’ll ever need to use more than 80% amp power .
Furthermore, the M4 features loopback connectivity which enables you to listen to your recordings in real-time. This feature is a must have if you’re want to podcast or live stream with your unit.
Prior to the release of the M-series, Motu had a track record of producing only high-end audio interfaces. However, as their first attempt at creating a mid-level interface, Motu dropped 2 different models which are the M2 and the M4. As the name suggests, the main difference between both units lies in their number of I/O channels. The M2 has 2 less line inputs than the M4 and has half as much balanced and unbalanced line outputs. The M2 also lacks a direct monitor mix knob. However, we couldn’t find any major disparity in their performance as they’re equipped with the same preamps, converters, and have the exact same features.
As much as we enjoyed using the M4, it does fall short in some regards. For instance, channels 3 and 4 don’t really comply with the established +4dBu output like inputs channels 1 and 2. They have something more around the +12 dBu range. That’s why we had to plug our +4dBu Fx unit to channels 1 and 2 which takes up the XLR sockets. Moreover, we dislike that there is no fast or practical way for us to control output channels 3 and 4. You won’t find a hardware option to control them which can be especially irritating in live situations.
Overall, the Motu M4 has established itself as one of the best mid-range audio interfaces in the market because of how powerful it is. With its transparent preamps, fast converters, and exceptionally detailed metering screen, you’re bound to get your money’s worth with the M4. So if you’re looking to add a powerful mid-range interface to your home studio go for the Motu M4.
MOTU M4 Benefits
The M4 has powerful converters that are used in some professional audio interfaces.
It contains transparent preamps that can drive almost any mic.
You can monitor through any high impedance headphone with no issues.
It features a detailed full-color LCD screen which you can use to gauge your I/O level with extreme precision.
It’s compact and light which makes it perfect for portability purposes.
MOTU M4 Drawbacks
Channels 3-4 do not comply with the +4dBu specification.
You won’t be able to vary the gain on channels 3-4 using a hardware knob.
According to our scoring model, you’ll see that there is a big amount of variance (1.6) between the highest and lowest scoring units. If you analyze the charts further, you’ll find that there are at least 2 points of variance within any given category. However, the Connectivity, Additional features, and Input/Output categories have the highest variance of the 5 categories. We could attribute the high variance in those categories to the Twin X DUO which outscores the SSL2+ and the M4 by a huge margin. Both of which have very similar scores in all 3 categories.
As you can see, the Twin X scores the highest in 4 out of 5 categories. It also aces the score in 3 categories which are Sound quality, Connectivity, and Additional features. With its TB3 connectivity and Built-in DSP, the DUO boasts almost zero latency. Moreover, it has some of the best preamps and converters in the market which is why it also outclasses both the SSL2+ and the Motu M4 in that regard. However, it does score the lowest in the Price to Performance category, but it’s only because of the diminishing returns on high-end units. So you’ll still get your money’s worth with the DUO.
We should also mention that both the Motu M4 and the SSL2+ can be solid choices if you’re on a tight budget. As you can see, both units have the same overall score (7.5) which means that they both offer very similar attributes. Additionally, they score exactly the same in 2 out of 5 categories which are connectivity and performance. In fact, the average deviation across their individual categories is only 0.4 which is extremely small. Nonetheless, both units are very powerful and offer a lot of commendable features considering their prices, so you can go for either and expect a similar high-grade performance.
However, based on our scoring model and extensive testing, the overall best USB-C audio interface is without a doubt the Twin X DUO. With its compact form, the DUO provides you with incredible sound quality, lots of additional features, and enough I/O channels to record anything. It’s one of the most powerful audio interfaces in the market which also allows you to run onboard plugins with zero latency. We can testify to the incredible work that UA has put towards perfecting their unit. That’s why if you’re looking for the best interface to improve your production, we would recommend you go for the Twin X DUO.
Frequently Asked Questions
Does a USB-C Audio Interface improve latency?
In most cases, yes. A USB-C port will have improved latency but that is not to say that there aren’t USB-B/USB 2.0 units out there that aren’t latency free, one such example is the RME Baby Face Pro. At the end of the day latency depends on how well the unit is built. A manufacturer that puts some love and care into their units will always address latency, regardless of the port type.
What is the most important aspect when choosing a USB-C Audio Interface?
Port type is one criteria of choosing an audio interface. The other main criteria include the I/O configuration and additional features such as on board DSP etc. Most modern interfaces are perfect for home production. Once you get past a certain price point, you’ll notice subtle differences in sound quality and you’re mostly paying for additional features at that point.
How much should I spend on a USB-C Audio Interface?
A good budget for an Audio Interface is anything $250 or more for home production, whereas a professional studio would spend quite a bit more, somewhere around $1500 to $2000 would be more than enough. Anything beyond that would either have a specific use case or you’ll have diminishing returns past that point.
What are other beneficial features of a USB-C Audio Interface?
It’s a modern port, so you can hook it up to most devices. Even if you are on the go and outside of your personal studio you can still take it with you without worrying about compatibility. Other than that USB-C audio interfaces come in a variety of classifications, so you have a wide range of interfaces at your disposal to choose from.