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Best audio interfaces 2022: 17 USB and Thunderbolt options for Mac and PC

Plugged in Arturia Minifuse 2 audio interface on a wooden surface
(Image credit: Arturia)

Getting hold of one of the best audio interfaces is one of the most important moves you can make as a home producer. In most situations, an audio interface is integral to any home recording setup, and if you spend any time at all making music on a PC or Mac you’ll want to grab yourself one. Having one of the best audio interfaces will enable you to get high-quality audio in and out of your computer, and to connect other essential studio gear and instruments during your recording sessions.

Once you’ve decided on the right audio interface, there’ll be no stopping you. You’ll be able to record electric and acoustic guitars, microphones, synths and any other musical equipment with an output, straight into a DAW of your choice. 

The market is awash with audio interfaces, all of which offer different features to turn your head. So, how do you choose the best audio interface for you and your studio? We'll tell you everything you need to know about what you need and why you need it, and we’ll also recommend some of the best audio interfaces you can buy right now. With options covering everything from multi-input Thunderbolt options, to great entry-level USB audio interfaces. We've also got the best audio interfaces for Mac users and audio interfaces for PC. There should be something for you here. 

We’ve included some expert buying advice at the end of this guide, so if you’d like to read more about the best audio interfaces we'd recommend you start there. If you’d rather get straight to our product choices, keep scrolling.

Best audio interfaces: Our top picks

If you’re looking for the best audio interface on a budget, then our go-to is the  Audient iD4 MkII (opens in new tab). It’s a simple, straightforward 2-in/2-out USB device that looks, sounds and feels great. It enables you to plug in microphones and instruments, and offers great value for money - so for those who’re buying their first audio interface, it’s a truly excellent choice.

If two inputs and outputs seems a bit restrictive, or you’ve got a bit more cash to splash, we’d take a look at the third-generation version of the Focusrite Scarlett 4i4 (opens in new tab). A USB-C audio interface that gives you double the number of inputs and outputs of the Audient, and sounds great. Focusrite makes some of the best interfaces on the market for the money, so if you’re looking for something solid, durable and easy to use, then you can’t go too far wrong with the 4i4.

Also consider the SSL 2+ (opens in new tab), a new 2-in/4-out audio interface that gives you at least a flavour of that magic 'SSL sound' at a remarkably low price.

At the top end, consider Universal Audio’s UAD Apollo Twin MkII, a 2-in/6-out audio interface that also enables you to use UA’s range of excellent DSP-powered plugins.  

Best audio interfaces: Product guide

The best audio interface for smaller budgets

Specifications

Connectivity: USB 2
Audio resolution: 24-bit/96kHz
Analogue inputs: 2
Analogue outputs: 2
Digital connectivity: None
MIDI I/O: No

Reasons to buy

+
Great value for money
+
Excellent preamp
+
Well thought-out

Reasons to avoid

-
Not much to complain about

Arguably the best audio interface you can buy for less than $200, The iD4 MkII is a simple two-input/two-output offering featuring a mic preamp – complete with phantom power for using condenser mics – as well as an instrument level DI for plugging in your guitar or bass, plus a smart scroll wheel enabling you to tweak settings in your software. On top of this, there’s a main output for your speakers and dual headphone outputs.

The whole thing is powered via USB-C and, with Apple’s camera connection kit, it can also work with an iPhone/iPad. However, for us the studio devilry is in the detail: Audient has really thought about everything with value and usability in mind, making what is a budget solution feel anything but inexpensive in use. The Audient iD4 MkII is, quite simply, the best USB audio interface we’ve tried at this price for a long time.

Read the full Audient iD4 MkII review

Get 'that SSL sound' at an amazing price

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Analogue outputs: 4
Digital connectivity: None
MIDI I/O: Ye

Reasons to buy

+
Great signal path for the money
+
The 4k button does add a 'sound'
+
Solid build quality

Reasons to avoid

-
You might not like the RCA outputs

A compact interface with pro features and connectivity, the SSL2+ promises an affordable version of ‘the SSL sound’, bringing the feel of a gazillion recordings made in 7-figure recording studios within reach of everybody.

This is the big brother to the standard SSL2, the main difference being that the 2+ adds two outputs to the 2-in, 2-out configuration of the 2, MIDI In/Out plus an additional independent headphone out (with both being able to monitor different mixes). There's also the 4k button which adds some extra presence and high-end zing (and, more importantly, makes you feel that little bit more 'pro').

There are two combi mic/line inputs with Hi-Z (impedance) options for switching between guitar and bass signals or those from synths or drum machines. A +48v option also allows the connection of both condenser and dynamic mics.

With great monitoring and recording quality and a flexible I/O configuration, the SSL 2+ comes highly recommended.

Read our full SSL 2+ review

A great competitively-priced option with plenty of connectivity

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/192kHz
Analogue inputs: 4
Analogue outputs: 4
Digital connectivity: None
MIDI I/O: Yes

Reasons to buy

+
New, improved preamp design
+
‘Air’ transformer stage emulation
+
MIDI I/O is useful

Reasons to avoid

-
4 combination inputs would be great

In our experience, Focusrite’s Scarlett USB interfaces have traditionally combined excellent sonics and audio flexibility at affordable price points, and the third generation units keep up the good work.

All units in the range have received physical and technical upgrades, with improved preamps (now up to 56dB gain), balanced connectivity throughout, and the inclusion of Focusrite’s ISA transformer preamp emulation option (Air). On the bus-powered Scarlett 4i4 you get two mic/line/instrument inputs with gain, two line-level TRS inputs and four TRS outputs.

The 4i4 supports Focusrite’s Control application, which means that a number of settings can only be made in the software. The app also handles low-latency monitoring.

As we’ve come to expect from the Scarlett series, in practice the sonics are neutral and the drivers reliable. The Air option tilts the frequency response towards high frequencies, and this can be great for taming undesirable proximity or adding high frequency lift.

With a decent software bundle included, this is a solid upgrade and a great affordable audio interface.

Read our full Focusrite Scarlett 4i4 3rd Gen review

High-quality audio and DSP-powered plugins

Specifications

Connectivity: Thunderbolt
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Analogue outputs: 6
Digital connectivity: Optical Toslink
MIDI I/O: No

Reasons to buy

+
Incredible audio quality
+
Superb UAD-2 plugins

Reasons to avoid

-
Thunderbolt only at the moment
-
No MIDI

Still a desktop-format 2-in/-6-out interface with 24-bit/192kHz capabilities, the Apollo Twin MkII would be almost indistinguishable from the original were it not now black rather than silver. It connects to your Mac or PC via Thunderbolt (there’s no cable in the box), but it has to be powered from the wall. The back panel and front edge house the inputs and outputs, while the top panel centres on a satisfyingly oversized knob. 

Also a DSP box for powering UAD plugin effects (you can choose from Solo, Duo and Quad options), the Apollo Twin MkII features the same game-changing Unison preamps as its predecessor, fed by the Mic/Line and Hi-Z ins. These enable a gradually expanding subset of UA’s classic hardware emulation plugins to be inserted directly into each input path. 

This is a musically empowering hardware/software hybrid that's capable of elevating even the humblest of home and project studios to genuinely professional-quality heights, and certainly one of the best audio interfaces you can buy.

Read our full Universal Audio Apollo Twin MkII review 

A compact, slick 2x2 audio interface at a competitive price

Specifications

Connectivity: USB 2
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Digital connectivity: None
MIDI I/O: No

Reasons to buy

+
Super compact
+
Very slick and stylishly designed
+
Decent five-part input metering

Reasons to avoid

-
No scaling on the controls

Komplete Audio 2 is a two-input, two-output design with two identical mic/line/instrument inputs. Connections are on space-saving combi XLRs with individual selector switches to select between line and instrument. 48V phantom power, meanwhile, is engaged globally via a single switch. 

In addition to the inputs, the front panel includes a hardware monitoring balance knob (Input/Host) and headphone output with independent control. 

The main output level is controlled from a large output level knob on the top panel. Here you’ll also find the input meters, alongside phantom and USB indicators. Round the back you’ve got the USB B connector, a pair of balanced outputs on TRS 1⁄4-inch jacks and a Kensington Security slot. 

This one makes our best audio interface list because in action the performance of the Komplete Audio 2 is as slick as its looks, and though the features are basic, it does its job admirably. And when you consider the excellent software bundle, it's great value.

Read our full Native Instruments Komplete Audio 2 review

Compact USB interface, plenty of features, incredibly intuitive to use and looks and sounds great

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Analogue outputs: 2
Digital connectivity: USB hub
MIDI I/O: Yes

Reasons to buy

+
Compact with small footprint
+
Solid sonics
+
Extensive and useful software bundle

Reasons to avoid

-
USB hub only suitable for low usage devices

MiniFuse is Arturia’s super compact interface range and we have the mid-sized MiniFuse 2 on test. It's a 2-in/2-out, USB powered unit with mic/line/instrument options for both inputs, MIDI I/O and a headphone output. It also incorporates a USB hub, although the power draw must be 250mA or less.

MiniFuse 2 has its own Control Centre software and is bundled with an Intro version of Arturia’s excellent Analog Lab, four effects, Native Instruments Guitar Rig LE and Ableton Live Lite, plus three month trial subs to Splice Creator and Auto-Tuner Unlimited.

The MiniFuse 2 sounds pretty good, with nice clean main outputs and plenty of volume from the headphones. The instrument inputs sound great and it’s good to see two identical mic/line/instrument inputs. But it’s the overall functionality that wins through, with plenty of backlit buttons and illuminated controls so it's obvious what’s going on. 

There are cheaper 2-in/2-out options, but MiniFuse 2 is a feature-rich device with extras that you don’t always get at this price. Factor in the impressive software bundle, generous five-year warranty and a choice of colours and you have a pretty decent package for the money.

Read the full Arturia Minifuse 2 review

One of the best compact audio interfaces around

Specifications

Connectivity: USB 2.0
Audio resolution: 24-bit/96kHz
Analogue inputs: 2 x XLR-1/4" combo (mic/line)
Analogue outputs: 2 x 1/4" TRS
Digital connectivity: None
MIDI I/O: No

Reasons to buy

+
Great, clean sound
+
Single dial makes it simple to operate
+
You’ll like the Monitor Mix solution
+
Sturdy build

Reasons to avoid

-
No angled front

The compact Evo range was launched at the NAMM Show 2020 to much acclaim.

You’ll find two combi mic/line inputs around the back of EVO 4, and one instrument level input at the front for connecting guitar or bass (which then overrides the first input around the back). 

Two speaker outs complete the connections and a central main dial controls the level of that output plus a number of other levels determined largely by which buttons on the top of the panel you press, these being 1 and 2 (for the input levels), and output (bottom right) plus a final button that means the dial adjusts the mix between the input and DAW. Using the headphone socket means the main dial controls this level.

The one-dial solution is beautifully implemented and designed to help make EVO a clever, compact desktop solution that sounds great.

Read the full Audient Evo 4 review

This mid-priced interface runs rings around more expensive devices

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Analogue outputs: 2
Digital connectivity: Stereo S/PDIF in/out
MIDI I/O: No

Reasons to buy

+
Solid build quality
+
Clean interference-free audio
+
Extensive visual feedback

Reasons to avoid

-
Fairly heavy

Revolution 2x2 incorporates Black Lion Audio's circuit design expertise into a 2-in, 2-out audio interface with a decent software bundle, including Presonus Studio One Artist, iZotope Elements Suite, Brainworx bx_ digital and Lindell 6X-500.

Revolution 2x2 is packed with quality components and even includes branded USB cables. Meanwhile, a new Macro MMC clocking circuit and PG-I power filtering and decoupling system prioritise audio fidelity. 

Visually, we think the unit is pretty understated and the feature set quite straightforward. Even so, nice touches include two identical mic/line/instrument inputs and zero-latency monitoring with mix control and input mono option.

The black design is nicely offset by backlit buttons, two-tone input level LEDs, a green USB indicator and multipart output level LEDs, so you have plenty of handy visual feedback and it really looks the part. We also like the smooth controls, chunky Monitor output knob and mostly solid build quality.

Revolution 2x2 looks unassuming, but is solidly built, easy to set up, surprisingly portable and brings crystal clear audio. It's extremely worthy of your time.

Read the full Black Lion Audio Revolution 2x2 review

9. M-Audio M-Track Solo and Duo

With a decent spec, these entry-level M-Tracks offer fantastic value

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/48kHz
Analogue inputs: 4
Analogue outputs: 4
Digital connectivity: None
MIDI I/O: Yes

Reasons to buy

+
Decent preamp design
+
Light and portable with solid build quality
+
Very affordable

Reasons to avoid

-
No MIDI connectivity

M-Track Solo and Duo are entry-level, USB-powered, audio-only interfaces with 2-in 2-out connectivity. Their feature sets are slightly different but underlying specifications are very similar. Solo includes one mic/line channel with switchable phantom power and one line/instrument channel. The main outputs are on unbalanced RCAs and the front headphone output is on an 1/8” mini-jack. Duo has a pair of mic/line/instrument inputs with switchable phantom power. Outputs are on balanced 1/4” TRS jacks, the headphone output is a 1/4” jack, and there are separate headphone/output level controls. 

A decent bundle of software includes the AIR Music Tech Xpand!2 synth, Eleven Lite guitar amp sim and 20 Avid plugins, as well as Pro Tools First M-Audio Edition and MPC Beats. Despite the amazingly low price, both units look well made and the black finish, recessed rubberised knobs and functional selector switches feel solid. 

Both interfaces use M-Audio’s Crystal Preamp design, and this provides you with plenty of clean neutral gain, great for lower output dynamic mics or weedy passive guitars. Both can sound pretty nasty when they’re overloaded, and so we kept well away from the red clip LED. 

M-Audio’s no-nonsense interfaces are simplicity itself, and weighing up the options, for the sake of an extra tenner we’d definitely go all out for the more flexible M-Track Duo.

Read the full M-Audio M-Track Solo and Duo review

Handy software control alongside a rock-solid audio performance

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Analogue outputs: 4
Digital connectivity: ADAT interface
MIDI I/O: Yes

Reasons to buy

+
Crystal clear mic preamps with plenty of headroom
+
Air transformer input emulation
+
Useful JFET instrument inputs

Reasons to avoid

-
Bus powering requires a 15W USB-C connection

Clarett is Focusrite’s premium USB range with three models and a decent bundle of software including Focusrite’s Red 2 and Red 3 plugins and Plugin Alliance’s bx_console Focusrite SC. Clarett+ focuses on improving audio performance rather than expanding that feature set.

The Clarett+ 2Pre on test has two mic pres with combo mic/line/instrument inputs, four balanced outputs, MIDI I/O and ADAT for a total of 10 ins and 4 outs. It is USB 2.0 compatible, with connection via a USB-C port that supports bus powering but from a device that provides 15W (or use the included PSU instead). Focusrite's Control software is easy to use and also available as a simplified iOS app, so you can control levels, including your low latency monitoring mix from your phone.

Clarett+ has improved independent A-D and D-A converters, slightly better noise figures throughout, and improved dynamic range. The mic inputs are silky smooth and have plenty of headroom, and the outputs are crystal clear and suitably noise-free. If you want to add some life to your input, the Air option does just that. Also excellent are the two JFET instrument inputs, substantially better than a regular instrument input.

The Clarett+ 2Pre is a reasonably simple interface with some very handy features, that offers subtle yet welcome improvements over its predecessor.

Read the full Focusrite Clarett+ 2Pre review

Great interfaces with hard-to-resist recording history magic on top

Specifications

Connectivity: USB-C
Audio resolution: 24-bit/192kHz
Analogue inputs: 2 (one for the 176)
Analogue outputs: 2
Digital connectivity: None
MIDI I/O: Yes

Reasons to buy

+
Classic UA recording channels and Vintage and 76 Compressor embellishments
+
UA quality at an affordable price
+
Attractive, intuitive, easy to use, plug-and-play design

Reasons to avoid

-
No scope for expansion beyond the limited I/O

The Volt range has the affordable market in its sights, and here we're looking at the Volt 176 and 276. These look very different to other UA interfaces and have a very different remit. There’s no plugin hosting, onboard software processing nor Console software. These are plug-and-play, with UA’s excellent preamps and, in the case of the two units here, the benefit of onboard analogue processing.

Each has combo XLR/TRS inputs on the front (just one for the 176), phantom power, instrument switches and a headphone port. Round the back you’ll find stereo outputs, the USB connector and MIDI In/Out ports. Both interfaces are bus powered with an external option and bundled software that includes Ableton Live Lite, Melodyne Essential and assorted instruments and effects like LABS from Spitfire Audio. 

With the 76 Compressor you choose 1176-style Vocal, Guitar, Fast or Off one-button compression, each delivering a characteristic flavour without going overboard. The Vintage option provides the tube emulation, gentle saturation, and top-end lift of UA’s classic 610 channel. 

The Volts are a radical departure for UA, but they deserve to shake up the budget interface market with a great design, a plug-and-play workflow and hard-to-beat audio conversion. It's bad news for other affordable interface makers: these are great!

Read the full Universal Audio Volt 76 series review

A hard-wearing 2-channel interface with high audio quality

Specifications

Connectivity: USB 2
Audio resolution: 24-bit/192kHz
Analogue inputs: 2
Analogue outputs: 2
Digital connectivity: None
MIDI I/O: Yes

Reasons to buy

+
Up to 24-bit/192kHz operation
+
Robust build quality
+
MIDI input and output

Reasons to avoid

-
Zero latency control affects monitor output

With high-quality Onyx mic pres, balanced analogue connectivity and operation up to 24-bit/192kHz, the bus-powered Onyx Producer 2.2 audio interface is more than capable of getting clean signals in and out of your DAW. There are two identical mic/line inputs with combination XLR/jack connectors. Each has a manual green backlit switch to select a Hi Z instrument, and there’s a global backlit switch for 48V phantom power. 

Input signals can be monitored with zero latency using the Input/DAW Mix knob, and rounding off the front panel are a large Monitor level knob and headphone output with level knob. Round the back you’ll find a pair of 1⁄4-inch jacks for the monitor output, and also a pair of MIDI connectors (In and Out), which is very handy. Throw in the robust metal case and you’ve got a compact workhorse device that should last for years. You also get a DAW, Tracktion T7, in the box.

Read our full Mackie Onyx Producer 2.2 review

A rugged 2-in/2-out audio interface with Yamaha preamps

Specifications

Connectivity: USB-C
Audio resolution: 32-bit/192kHz
Analogue inputs: 2
Analogue outputs: 2
Digital connectivity: None
MIDI I/O: Yes

Reasons to buy

+
Built to last
+
Yamaha preamps
+
Built-in DSP processing

Steinberg has pimped-up its UR range of audio interfaces, introducing USB 3.0 models for PC, Mac and iOS. The UR22C, on test here, is the most affordable of these.

Each of the interfaces offers USB Type-C connectivity (or USB 3.1 Gen 1 SuperSpeed, to give it its official title) and operates at 32-bit/192kHz audio resolution. There’s MIDI I/O, too, as well as DSP that provides zero-latency effects that can be used when monitoring. These can be accessed via the dspMixFx mixer.

Unsurprisingly, the UR22C is a 2-in/2-out audio interface. You get a couple of balanced Neutrik combo inputs, each of which sports a Yamaha D-PRE mic preamp, and two balanced line outputs.

With its rugged metal casing, the UR22C is the best audio interface for you if you want something that can be slung in a backpack without fear.

Read the full Steinberg UR22C review

One of the best audio interfaces if you need a portable powerhouse

Specifications

Connectivity: USB 2, Lightning, USB OTG
Audio resolution: 24-bit/48kHz
Analogue inputs: 2
Analogue outputs: 2
Digital connectivity: None
MIDI I/O: Yes

Reasons to buy

+
Completely portable
+
Works with mobile devices
+
Record two channels simultaneously

Reasons to avoid

-
There are better options if you don't need portability

The follow-up to the original iRig Pro Duo, the new version offers two analogue combo inputs so that you can connect and simultaneously record your favoured combination of instruments and mics. These inputs come with updated Class-A preamps, adjustable gain (increased for this model) and phantom power. There’s MIDI I/O, too, along with two balanced 1/4-inch outputs and a headphone output.

You can engage the direct monitor switch for latency-free monitoring of the incoming signal, and the iRig Pro Duo I/O comes with a USB-C cable for easy compatibility with modern devices (Lightning and USB-A cables are supplied, too). There are new dedicated PC drivers as well, along with a refreshed rubberised finish.

The iRig Pro Duo I/O can be bus-powered or run on two AA batteries and ships with a large bundle of software. It’s compatible with iOS, Android, PC and Mac so could be just the thing if you need to record on the move and in your studio.

Read the full IK Multimedia iRig Pro Duo I/O review

A classy audio interface with a wealth of connectivity options

Specifications

Connectivity: USB 2
Audio resolution: 24-bit/192kHz
Analogue inputs: 4
Analogue outputs: 4
Digital connectivity: ADAT I/O and S/PDIF I/O
MIDI I/O: Yes

Reasons to buy

+
Great sound
+
Loads of connectivity
+
Stylish design

Reasons to avoid

-
Pricey compared to similar models

AudioFuse is an attractive and portable Mac, PC and iOS-compatible interface with a raft of features. Despite its compact frame, we found there to be plenty of connectivity on offer. Along the front edge, you’ll find combi inputs and two fully independent headphone feeds. In turn, these can accommodate both mini-jack and 1/4-inch plugs. 

At the back, there are speaker outputs for two pairs of monitors, line level connectors, MIDI In/Out ports (which, due to size restrictions, have been replaced by mini-jack connectors, which you’ll find in the box) and - for digital interfacing - both S/PDIF and ADAT In/Out. There are also inserts for inputs 1 and 2, allowing you to track through hardware compressors or channel strips. 

AudioFuse connects via USB 2, but USB connectivity goes further; Arturia has built a USB hub into it, providing three extra USB ports. AudioFuse provides a beautiful and contemporary approach to USB audio interfacing with a great design, compatibility with a huge range of possible audio sources, a great sound and a highly tactile control set.

Read our full Arturia AudioFuse review

A premium audio interface with onboard DSP

Specifications

Connectivity: USB 2 and Thunderbolt
Audio resolution: 24-bit/192kHz
Analogue inputs: 8
Analogue outputs: 8
Digital connectivity: S/PDIF, ADAT
MIDI I/O: No

Reasons to buy

+
Crystal clear discrete mic preamps
+
Excellent selection of onboard processing
+
Highly flexible routing
+
Compact desktop footprint

Reasons to avoid

-
Expensive

Antelope Audio is one of a small group of manufacturers that produces premium audio interfaces with onboard processing. In 2019 it launched an improved architecture, Synergy Core, that uses both FGPA and DSP chips to deliver near-zero latency onboard processing during recording or mixing. 

Zen Tour is its 8-in/14-out compact desktop-style interface and this has now been upgraded to Synergy Core with 2 FGPA and four DSP chips delivering up to 256 FX instances.

On the front you get four DI inputs (switchable to line level if required), two individually configurable HP outs and two handy transformer-based re-amp outputs, so you can send your DI back to a guitar amp input. 

On the back are four combi XLRs for mic/line ins, one pair of monitor outputs on 1/4” TRS jacks, S/PDIF in/out, ADAT in/out and eight line-outs on 25-pin D-type. 

Zen Tour Synergy Core comes bundled with 36 effects, including preamps, EQs, compressors, guitar amps and support for Antelope’s Edge and Verge modelling mics. The design of these is first class, with some classic hardware emulations.

We found it also delivers fantastic fidelity, with discrete ultra-linear preamps and premium clocking courtesy of Antelope’s acoustically focused clocking. 

Zen Tour Synergy Core is an incredibly capable unit that is pretty easy to use and sounds fantastic.

Read our full Antelope Audio Zen Tour Synergy Core review

Steinberg is offering a genuine high-end audio interface alternative

Specifications

Connectivity: Thunderbolt 2
Audio resolution: 32-bit/384kHz
Analogue inputs: 28
Analogue outputs: 24
Digital connectivity: ADAT, S/PDIF, AES/EBU I/O
MIDI I/O: Yes

Reasons to buy

+
Great performance and loads of I/O
+
Intuitive setup

Reasons to avoid

-
No Thunderbolt cable included
-
Front panel configuration is fiddly

Steinberg entered the Thunderbolt audio race with the the AXR4, a rack-mountable interface aimed at professional producers and engineers. This 28-in/24-out box offers latency-free DSP-powered monitoring and effects, stacks of I/O and plenty of routing flexibility. Up front you’ll find four Neutrik combo inputs and two headphone outputs, while the back panel houses eight TRS line inputs, eight TRS line outputs and two sets of ADAT I/O doubling as S/PDIF. 

The second pair provides an alternative AES/EBU Sub-D connector. MIDI I/O sits alongside word clock I/O, while two Thunderbolt 2 ports enable computer connection and daisy-chaining of up to three interfaces. The four hybrid mic preamps benefit from refined transformer circuitry and Rupert Neve Designs SILK processing, while DSP effects include the VCM 276 compressor, VCM EQ601, the Sweet Spot Morphing Channel Strip and the REV-X reverb. 

The Steinberg AXR4 oozes quality from every pore, making it a serious contender in the pro audio interfacing arena.

Read our full Steinberg AXR4 review

Best audio interfaces: Buying advice

Best audio interfaces: A pair of Focusrite interfaces stacked on top of each other

(Image credit: Future)

Do you need an audio interface?  

If you are a musician who wants to make great quality recordings and listen back to them on decent speakers, then you really need an audio interface. They allow you to record any audio into your computer or smart device – from strumming guitars and your singing through to a complete band or orchestra – and then mix that audio into a song in your DAW and hear the results back through pro-grade speakers.  

How many inputs and outputs do I need?

When choosing the best audio interface for home studio and beyond, the first thing you need to work out is the number and type of inputs and outputs you need. If you only want to plug in one microphone or instrument at a time – if you're a solo producer who generates most of their sounds inside the computer, this is probably you – just one or two inputs will be plenty, but if you want to record a live band, you’ll need to think about much more than that. Multiple outputs can also be useful if you want to set up separate headphone mixes (if you're a DJ, for example) or send audio elsewhere for further processing.

What types of inputs and outputs do I need?

On most audio interfaces you’ll typically find both XLR and 1/4-inch inputs, often combined into combo connectors so that you can plug mics, guitars, synths and the like into the same input. Many interfaces also offer a phantom power option, which is required if you want to use certain microphones.

Some audio interfaces also have MIDI I/O on them, which could save you from having to buy a separate interface for external MIDI gear. If you only intend to use a MIDI keyboard, though, remember that this could plug into one of your computer's other USB ports, so MIDI I/O might not be an essential requirement.

Best audio interfaces: Universal Audio Apollo

(Image credit: Future)

How to connect your audio interface 

Most audio interfaces connect to your computer by USB or Thunderbolt or by using a Lightning adaptor with iOS devices. The cable required for connectivity usually ships with the interface but not always with Thunderbolt 3 and Lightning, so do check what you get in the box. 

Most interfaces are class-compliant, so will work out of the box –  just plug them in and start using them straight away. Some come with extra software you will need to access some of their more detailed functions and routing. Many, especially mobile interfaces, are bus-powered so you don't have to plug a mains power supply into them.

Specs always include the numbers of audio inputs (as XLR or 1/4-inch jack or a combination of the two) and audio outputs. Inputs indicate the number of instruments or microphones you can connect up to record simultaneously. Check the interface has a phantom power option if you want to connect up a condenser mic which requires external power. The number of outputs refers to the number of connections available to your studio speakers or other hardware boxes, including outboard effects. 

What is low latency recording? 

You’ll find that most contemporary audio interfaces offer a low-latency recording option, which means you can stay in time with your project when you’re adding more tracks. Some interfaces also promise latency levels that are low enough to use effect plugins in ‘real-time’ on the input as you record, while others have their own DSP processing built into them. 

Best audio interfaces: Mackie Onyx Producer 2.2

(Image credit: Mackie)

What should I expect to pay for an audio interface? 

In the end, the best audio interface for you will at least partly come down to price, so you’ll be pleased to know that our list of recommendations in this guide covers a broad range from beginner to pro. We’d also recommend reading our guide focused specifically on the best budget audio interfaces if you have less to spend.

Interfaces are serious pieces of kit that should keep the audio signal quality high throughout the recording process, but you needn't pay serious money for them. If you are an in-the-box producer, you might only need one input at any one time to record, plus a couple of outputs to your speakers. Even a singer/guitarist can get away with just two inputs, and a decent 1 or 2-input/2-output audio interface only costs from around $/£50 up to $/£200. Add more inputs and better quality preamps on these  – which will give you a better quality audio recording – and you could pay anything from $/£200 to $/£700 for a medium-sized interface capable of recording all of the outputs from a band, for example.

Pro grade interfaces with fast connectivity, the ability to power software (see Universal Audio) and digital inputs and outputs can tip into four figures – sometimes up to $/£2,000 – but you might not need any or all of the extras they offer. Many interfaces support an array of digital ins and outs like ADAT and S/PDIF, for example, two digital standards you only need to take into consideration if you have other audio gear with these inputs and outputs included.

There are many companies making audio interfaces but some brands that score consistently well in our reviews and we stand by in terms of build quality, features and value for money are Apogee, Audient, Focusrite, Native Instruments, Steinberg, SSL and Universal Audio. 

How we test audio interfaces

Audio interfaces are essentially devices designed to record audio into your computer DAW, and play it back out. The key factors when testing them are how easily they do this and the level of audio quality they are capable of delivering while doing so. 

Many audio interfaces are 'plug n play' so will automatically be picked up by your computer and DAW when you first connect them, so setting up should be easy. Your DAW should then list all of the audio interface's physical inputs and outputs, often as selectable options on its input and output channels. 

Sound quality is determined by an interface's A-D/D-A convertors, sample rates and frequencies quoted in their specs (24-bit/96kHz, for example). We test for sound quality by recording several sources via the interface's mic and line inputs, and judging the playback quality against that expected from the specs. We also compare the same material recorded with our reference audio interfaces that we use on a daily basis. 

Some audio interfaces come with extra bespoke software that lets you select input and output configurations and might also add other routing options or even effects. How easy this extra software is to use is also an important factor. 

We also consider latency when testing interfaces. This is the time it takes for audio to go into and out of your computer DAW via the audio interface. If this is slow, the latency figure is high so can result in a delay between you playing a note and then hearing it. This is obviously not practical if you are recording some playing and attempting to be in time with your DAW playback.

Read more about how we test music making gear and services at MusicRadar.

Andy has been writing about music production and technology for 30 years having started out on Music Technology magazine back in 1992. He has edited Future Music, Keyboard Review, MusicTech magazines and currently runs Computer Music which he helped launch back in 1998. He owns way too many synthesizers.