What is an audio interface?

An audio interface is the bridge between your instruments or microphones and your computer. If you want to record your sound, for example, if you’re a music producer needing to record a track or a content creator recording a podcast, you’ll need an audio interface.

It allows you to connect various audio sources, including microphones, electric guitars, keyboards, and other instruments, and convert their analog signals into digital information (1s and 0s) that your computer can understand. It does this while ensuring your recordings are clear and precise.

Once your computer has processed this information, the audio interface converts the digital audio signals back into audio signals, i.e., waveforms that you can listen to through your headphones or monitors – all whilst maintaining the quality of the original sound.

Audio interfaces have another key use – they boost microphone signals, which is vital for recording. Microphones often produce weak signals that need to be amplified to a suitable level for recording. The preamps in an audio interface boost these signals without introducing noise or distortion, resulting in a clean, professional sound.

To find the right audio interface for you, check out our guide to the best audio interfaces on the market right now.

Microphone preamps

A high-quality preamp is crucial for achieving the best sound in your recordings. As we’ve discussed, an audio interface amplifies weak signals from microphones, ensuring they’re strong enough for clear and precise recording – they use preamps to do this.

Microphone preamps are a key thing to consider when looking for an audio interface. In this regard, we recommend the Presonus Quantum ES 4 for its custom MAX-HD preamps with +75 dB of gain. These are the result of decades of research and design, and they amplify microphone signals to an appropriate level whilst always maintaining the quality of the original sound source.

The Focusrite Scarlett Solo is another audio interface known for its preamps. Its preamps can be enabled with Air mode – ideal for recording acoustic guitar or soft vocals in which you need some added brightness and openness.

Preamps with emulation capabilities are also worth considering. The Universal Audio Volt range, for example, includes an inbuilt vintage mode that emulates classic microphone sounds. This allows you to achieve a variety of tonal characteristics without needing multiple microphones.

Having such versatility takes a simple box that boosts and converts audio signals and turns it into something that lets you experiment with different sound profiles.

Each audio interface’s preamp is unique to itself, so it’s important that you find the right one to suit your recordings.

Things to consider when buying an audio interface

Inputs and outputs

One of the first things you should look at when choosing an audio interface is the number of inputs and outputs it has – does that match with how many you need? Think about the instruments and microphones you plan to use. If you’re recording multiple sources simultaneously, look for interfaces with multiple inputs.

Outputs are equally important for connecting speakers and headphones. Ensure the interface provides enough outputs for your setup, including main outputs for monitors and additional ones for headphones or external processors.

Phantom power

Phantom power is essential if you use condenser microphones as these require external power to operate.

Most audio interfaces offer phantom power, but it’s important to check that the interface can supply +48V phantom power to accommodate your microphones. This feature is usually switchable, allowing you to turn it on or off as needed for different types of microphones.

Preamp quality

The quality of the preamps in your audio interface is vital for capturing clear and noise-free recordings. High-quality preamps amplify the signal from your microphones without adding unwanted noise or distortion.

Sampling rate and bit depth

Sampling rate and bit depth determine the audio resolution and quality.

Higher sampling rates (e.g., 96kHz or 192kHz) and bit depths (e.g., 24-bit) capture more detail and provide better sound quality, which is needed for professional or high-fidelity recording purposes.

Sound quality

This is subjective, and it’s important to remember that an audio interface isn’t a solution for better sound quality. Rather, the quality of the microphone preamps and the sampling rate and bit depth will tell you how well the interface retains the clarity of the original sound source.

You want something that converts your musical signals precisely, without adding distortion – this is the point of an audio interface, to keep your recordings clean and ready for editing in your DAW.

Latency

Latency refers to the delay between inputting sound and hearing it through the interface, so it goes without saying that this delay should be as short as possible.

Low latency is crucial for real-time monitoring and recording – look out for these words when choosing an audio interface! It’s often achieved through efficient drivers and hardware design, and some interfaces offer direct monitoring, which bypasses the computer to provide near-zero latency, allowing you to hear yourself without delay during recording sessions.

Features for monitoring

Monitoring your sound is crucial when it comes to capturing professional recordings.

Most interfaces will have some form of monitoring outputs, as mentioned earlier, such as speaker outputs or headphone outputs, but you should also look for independent volume controls for managing different mixes and direct monitoring options for latency-free monitoring.

Build quality

As with anything you buy, you should look for the quality of the build and craftsmanship.

If you plan to use the interface in different environments or transfer it regularly, it needs to have a robust, durable construction. Metal chassis, sturdy knobs, and high-quality connectors are all good things to look out for as they contribute to a longer lifespan and better performance.

Interfaces with auto gain

Auto gain is a feature that automatically adjusts the input level to the optimal setting, ensuring your recordings are neither too quiet nor too loud. This is great for beginners as it simplifies the setup process, getting rid of the need to manually set gain levels. With auto gain, you achieve the right balance quickly, preventing distortion and maintaining sound quality.

An excellent example of an audio interface with auto gain is the Focusrite Scarlett 4th Gen – one of the most popular audio interfaces on the market.

The auto gain feature in the Scarlett 4th Gen ensures consistent levels without you constantly making technical adjustments. It’s a great choice for both new and experienced musicians and producers – who doesn’t want a speedier setup?

What is loopback?

Loopback technology is a feature in some audio interfaces that allows you to route audio signals from your computer back into the interface. This can be particularly useful for musicians and content creators. For guitarists using pedals and effects, loopback enables you to integrate these external effects seamlessly with your digital setup.

You can record the processed signal directly, making it easier to capture your unique sound. A great example of an audio interface with loopback functionality is the Steinberg IXO range. These interfaces offer high-quality sound and robust features, including loopback, making them ideal for both music production and live performance setups.

The Steinberg IXO12, for instance, allows you to easily route audio for various applications, ensuring flexibility in your recording process.

Loopback is also excellent for streaming. It lets you capture and mix different audio sources, such as your microphone and computer audio, and send them to your streaming software. This is perfect for live-streaming performances, podcasts, or gaming, where you need to manage multiple audio inputs seamlessly. You can use loopback functionality to incorporate background music, for example, which is ideal for gamers.

It can also be very useful for live musical performances, allowing you to route all your audio through the interface and broadcast it live to your fans.

Features of a budget audio interface

If you’re looking for an affordable interface, keep an eye out for the quality of the basics. e.g., good preamps and support for 24-bit/96kHz audio quality. An excellent example is the SubZero AI1 2-Channel USB Audio Interface found in the SubZero BASE-1 2-Channel Audio Interface Bundle.

Budget interfaces like the SubZero AI2 are well-suited to home studios, podcasting, and beginner musicians. They offer a good balance of quality and affordability, making them ideal for those just starting out. It’s a good idea to also look for interfaces with easy-to-use software, sturdy build quality, and USB connectivity for convenience.

Affordable audio interfaces are perfect for small-scale recording projects and provide a cost-effective way to achieve decent sound quality.

Features of a high-end audio interface

High-end audio interfaces come packed with advanced features that cater to professional recording needs. They often include multiple types of digital inputs and outputs, such as ADAT and SPDIF, which allow you to integrate additional gear and expand your recording capabilities. These interfaces also boast superior preamps, high-resolution audio conversion, and robust build quality.

A prime example of a high-end audio interface is the Universal Audio Apollo Twin X DUO Gen 2. It includes Unison-enabled preamps for precise emulation of classic analog hardware, Auto-Gain functionality, and bass management. The Apollo Twin X  DUO Gen 2 also supports Thunderbolt 3 connectivity for ultra-low latency and quick data transfer.

These premium interfaces are ideal for professional studios, serious musicians, and audio engineers who demand the best performance and flexibility.

FAQs

What does an audio interface do?

An audio interface converts analog signals from instruments and microphones into digital signals that your computer can process. It also converts digital audio from your computer into analog signals for playback. This ensures high-quality recording and playback, providing better sound clarity and control.

Do you really need an audio interface?

You need an audio interface if you want to record high-quality audio and use professional microphones or instruments with your computer. It significantly improves sound quality compared to built-in computer sound cards and provides essential inputs and outputs for recording and playback.

Do audio interfaces improve sound quality?

Audio interfaces improve the quality of your recordings, more so than your computer’s sound card. It does this through better analog-to-digital and digital-to-analog conversions. However, it’s not a solution for poor-quality microphones or sound sources – the aim of an audio interface is to ensure clear and accurate recordings.

Final thoughts

Finding the right audio interface can significantly improve your recordings, and if you’re new to this world of audio gear, we hope our guide has taught you everything you need to know! We’ve covered various options, from budget-friendly models to high-end choices with advanced features. Each offers something unique, catering to different needs and preferences.

It’s important to consider exactly what you need for your setup. Whether it’s auto gain for ease of use, loopback for integrating effects, or top-notch preamps for superior sound quality, there’s an interface that suits your needs.