How to Choose an Audio Interface

We’ve broken down everything you’ll need to know to help you pick a great audio interface and packed it into a quick 5 minute read!

The audio interface is at the heart of most recording setups and is designed to process audio at a higher quality than your computer’s sound card. An interface allows you to connect all the key components of your set-up - your microphones, guitars, monitors, headphones, computer etc - and allows them to communicate and send information to and from one another.

Each interface will feature a different number of inputs and outputs for plugging in various bits of gear; some interfaces come with just 1 input, others offer far more. You'll also find inputs for your headphones and volume controls for your monitors.

Preamps

Microphone inputs on audio interfaces will feature a preamp to help boost the signal up to a suitable level for your computer to then work with.

In a nutshell, more preamps available will mean a higher price point. Better quality preamps also mean a higher price but also means better quality audio.

Imagine you’ve got your favourite high-quality microphone going into a low-quality preamp on your interface - it’s going to undoubtedly have a negative impact on your sound. Better mic preamps mean clearer and more accurate recordings.

Digital Audio Conversion

The main job of an audio interface is to convert analogue audio signals (from your microphone, instrument etc) to digital signals and vice versa. The quality of the converters handling these processes can have a big impact on your sound. Check out the Ultimate Guide later on for more information on this process!

Inputs & Outputs (I/O)

The number of inputs and outputs you will need is dependent on what you want to be able to record. Some interfaces feature as few as 1 or 2 analogue inputs, others offer up to 8 or 16.

More inputs often equal a higher price, but it doesn’t always ensure higher quality per input. Some interfaces may offer less features but at a higher quality. Quantity and quality do not always correlate.

It’s also worth considering future proofing your setup – you may only think you need 1 or 2 inputs right now, but in a year or two, you may want to record bigger sessions. It could be worth looking at options with more ins and outs, just in case.

Make sure you don’t get fooled by the number inputs and outputs listed on an interface. Very often this number includes the digital inputs as well as the analogue ones – which are the ones you’ll be plugging mics and instruments into. Focus on the number of XLR/mic inputs, as these will be your bread and butter for most situations.

We go into more detail about the different types of analogue and digital inputs later in the Ultimate Guide!

Audio Interfaces have a variety of ways to connect to your PC or Mac, the main connection types to look out for are USB and Thunderbolt.

Make sure the option you’re considering is compatible with your computer before you purchase!

All computers come with USB ports, whereas Thunderbolt connectors (which reuse the USB-C connection) are more commonly found on Macs. USB 2 is far more common but it’s slower when it comes to data transfer.

Thunderbolt is becoming the gold standard for home and pro recording as it comes out on top for data transfer speed, which means less latency and faster, smoother recording and playback.

If your computer offers a Thunderbolt connection type, it might be worth the extra cost.

Extra Software

Many interfaces come with software that can be very useful, especially if you’re still getting started or finding your feet.

A lot of interfaces come with a light version of popular Digital Audio Workstations which is a great way to see which software suits you best before investing.

Other brands often include their own instrument and effect plug-ins, such as Universal Audio. It’s worth checking out what extra software comes with an interface as it could make a big difference to your overall music making experience, especially if you’re getting started or looking to expand your arsenal of software!

On-Board DSP

DSP stands for digital signal processing. As we mentioned in the previous section, many companies have made a big name for themselves in the plugin market by offering a wide range of tools for helping to shape your sound, often emulating famous hardware effects.

On-board DSP gives the user the ability to run these plug-ins and similar software on the interface rather than using up processing power of their computer, which means your computer can focus on processing other things.

Stick around until the Ultimate Guide below for more information on DSP!

Focusrite

Focusrite is one of the leading manufacturers of audio interfaces and studio hardware, catering to both the seasoned professional and the home studio hobbyist with high-quality, reasonably-priced gear. AS such, Focusrite is often the entry point for many musicians looking to build a project studio from scratch. Focusrite’s rich history began in 1985 when Sir George Martin asked legendary console designer Rupert Neve to create a mic preamp with EQ for the console at Air Monserrat. As the company grew, the ISA design was then used in Focusrite’s Studio Console, of which only 10 were made; a few are still in use today. From entry level interfaces to professional studio solutions, compact desktop boxes and rackmount hardware; Focusrite has plenty of options to suit any recording setup.

Behringer

Behringer believe in producing life-changing products at a price point that gives anyone the ability to fulfil their musical dreams. Founded in 1989, as a fledgling musician and sound engineer, Uli Behringer couldn’t afford the necessary equipment for his own studio. Initially building products just for himself, he soon began supplying them for his friends, too. Thus, Behringer was born, along with its philosophy to continue to produce products at prices that everyone can afford. To this day Behringer continue to produce great, affordable products across a range of categories and audio interfaces is no exception with plenty of options that anyone can get their hands on.

Universal Audio

For more than 60 years, Universal Audio have been at the forefront of creating recording equipment. Founded in 1958 by Bill Putnam Sr., Universal Audio has been synonymous with innovative recording products since its inception. Putnam was the inventor of the modern recording console, the multi-band audio equalizer, and the vocal booth, and he was the first engineer to use artificial reverberation in commercial recording.

In 2012, Universal Audio introduced Apollo audio interfaces, providing analog studio sounds and realtime workflows via onboard UAD digital signal processing. More recently in 2021, with the introduction of Volt bus-powered USB audio interfaces, Universal Audio presented classic analogue sounds and workflows at an even more accessible price point. Volt’s Vintage Preamp and all-analogue 76 Compressor provide powerful tone shaping tools that add tons of classic character and polish to your tracks.

Audient

Audient was founded in 1997 and its headquarters are based in the UK. Its mission is to make professional audio quality available to everyone. A dedication to designing products that balance quality and simplicity, including analogue recording consoles, audio interfaces, mic pres and monitor controllers, has seen Audient build a strong community of music makers in professional and home studios across the globe. Audient also operates its sub-brand, EVO which aims to make recording both easy and accessible to creatives.

Apogee

In 1985, Apogee developed technology that addressed the inherit brittleness and distortion heard on the new listening medium of the day, compact discs (CDs). Apogee’s unique 924 and 944 anti-aliasing filters were used in high-end Sony and Mitsubishi digital recording systems to make the CD format sound warmer and more like analogue. Apogee continues to innovate with technologies and products that push the envelope. From the groundbreaking 924 and 944 filters to leading the studio-quality home recording revolution with Duet and Ensemble to MiC and JAM - the first pro products for iOS recording - Apogee creates cutting-edge tools that artists, audio professionals and audiophiles love and trust.

PreSonus

PreSonus Audio Electronics Inc was founded in 1995, on the principle of designing innovative audio products that provide professional sound quality and features without sacrificing affordability. For the last 25 years, their goal was simple: build innovative solutions for musicians, content creators, producers, and audio engineers. Today, PreSonus is a leading designer and manufacturer of both recording and live-sound hardware and software solutions. Whether you're a first time, bedroom player just looking to record a few ideas or a full time professional producer, PreSonus have an interface to suit your needs.

Solid State Logic (SSL)

Solid State Logic was founded in 1969 by the late Colin Sanders CBE. The company’s first products were switching systems for pipe organs for which Colin coined the phrase 'Solid State Logic' as a descriptor. Colin then started Acorn Studios in the village of Stonesfield, Oxfordshire, where he lived, and began making his own consoles. By 1976 he had built the first A Series console; a total of two were made and sold. SSL 2 and SSL 2+ are more than just audio interfaces, they are the centre of your new Solid State Logic studio. Class-leading mic preamps, Legacy 4K analogue enhancement, studio-quality monitoring and the incredible SSL Production Pack software bundle. SSL have been designing cutting-edge mixing consoles and processing tools for the world's finest recording studios for over four decades. Now you get all that hit-making know-how in your own personal studio.

Steinberg

Steinberg audio interfaces are the result of Steinberg and Yamaha’s combined 165 years of creating world-leading musical instruments, electronics and software. Together they have produced the UR, UR-C, UR-RT and AXR series interfaces which all have exceptionally high audio quality, flexibility and reliability at heart of their design. Whatever and wherever your production needs, Steinberg have an audio interface that will surpass your expectations.

Antelope Audio

Antelope Audio has more than 20 years of experience in manufacturing innovative digital audio equipment with a signature high-definition sound. Their Thunderbolt & USB audio interfaces range from portable desktop devices for the home studio to rack-mountable 64-channel converters for large professional studios, broadcast houses, post production (incl. Atmos) and live venues.

Manufactured in the EU, with hand-built discrete microphone preamps, pristine digital-to-analogue conversion, industry-leading clocking technology, a powerful control panel and DSP FX, these devices are for those who want the best of audio quality with plenty of flexibility and features at a reasonable price.

What are the main input types?

There are 3 main types of analogue inputs – Mic level, Line level and Instrument level. Some interfaces come with inputs capable of receiving all 3 of these signal levels, often on the front. However, these signal levels are not equal in strength.

Mic Level

A Mic level input often comes in the form of a 3-pin XLR female input and is designed to receive signals that are relatively low in strength. You will often find preamps on these inputs designed to amplify the input signal from low level (Mic level) devices, such as dynamic mics or acoustic pickups, to a Line level signal. These inputs will often feature an optional 48V of phantom power for powering condenser mics.

Line Level

Line level is the signal strength required by your DAW to record. As well as Mic level inputs, you’ll often see additional inputs labelled as Line level. These are designed to be used with a range of equipment, such as studio outboard gear (like compressors) and synths that have a higher output level.

Instrument level (Hi-Z)

An Instrument or Hi-Z input is perfect for plugging in guitars, basses, and other similar high impedance instruments. Some interfaces will offer the option of switching specific inputs between line and instrument level, either via software or a physical switch.

What is a Word clock?

A word clock is a precise oscillator used to sync multiple digital audio devices. In most home studio settings, the audio interface clock operates as the master clock for any additional devices, keeping everything in sync with each other. However in pro studios, which often require more complex signal routing, many engineers choose to use a stand-alone device.

Analogue-to-Digital / Digital-to-Analogue Converters

AD Converter

Analogue to digital (AD) converters transform analogue audio signals, such as the output of a preamp or other piece of outboard gear, into digital audio signals that can be processed by your computer.

An audio interface converts analogue signals from instruments, microphones etc. and converts them into a digital signal for your computer to process.

DA Converter

Digital to analogue (DA) converters work in reverse, converting digital audio signals, such as those played by your DAW or web browser, into analogue audio signals that can be recreated by your studio monitors or headphones.

They also perform the opposite process, converting digital signal from your computer to an analogue signal to be played through your monitors or headphones.

What is Sample Rate?

Sample rate is a measurement of how many samples your DAC takes per second when sampling audio. DACs take tens of thousands of ‘digital snapshots’ each second when sampling an analogue audio signal. The more samples the DAC is able to capture, the more accurately it can recreate the audio signal in the digital domain.

By using a higher sample rate, your DAC can capture more information and more accurately recreate the audio signal. However, using high sample rates comes at a cost. It also creates more stress on your processor, restricts the number of channels you can work with, and creates significantly larger audio files.

By adjusting the sample rate and bit depth of your DAC, you can control the quality of your digital audio recordings and find a happy medium but it’s best to initially record at the highest possible level available.

What is Bit depth?

Bit depth controls the amount of dynamic range in a digital audio recording, or the amount of space between the loudest and quietest sounds. Most professional DACs operate at the following bit depths:

• 16-bit

• 24-bit

• 32-bit float

A bit is a binary digit, or a single unit of code. A bit only has two values: 1, or 0. On, or off. With multiple bits, you can create more combinations, resulting in more values and more accuracy.

The minimum standard bit depth for CD-quality digital audio is 16-bits but using a higher bit depth offers greater dynamic range, improved signal-to-noise ratio and more headroom. Higher bit depths allow you to make the loud moments louder and quiet moments quieter without introducing additional noise.

DSP

DSP stands for Digital Signal Processing. Some audio interfaces offer the capability to run plug-ins and effects via DSP instead of relying solely on your computer. By lifting some of the processing workload from your computer and letting your DSP device handle it, you can expect a smoother computer performance and lower latency overall.

Many brands such as Universal Audio and Antelope are known for their DSP capabilities and it’s a key selling point for many adopters. It can definitely be a crucial factor to consider when comparing prices of interfaces, especially if you’ll be using an older computer with less internal RAM.