Do Audio Interfaces Affect Sound Quality?

Maybe you’re a podcaster with a growing audience or an aspiring musician with lots of original content to record, and you’re thinking of buying an audio interface to up your game. But you’re not sure if it’s the right move. You’re wondering: do audio interfaces affect sound quality? 

Audio interfaces affect sound quality to some extent through amplification and conversion. However, all midrange interfaces have adequate circuitry to prevent distortion and quality loss. So, more expensive options don’t usually make a notable difference in sound quality except when recording music.

In this post, you’ll discover how an audio interface can affect sound quality and why an expensive one doesn’t necessarily provide better sound quality. You’ll also learn about the options that affect an audio interface’s price and more.  

Audio Interface

What Does an Audio Interface Do?

An audio interface is a specialized device that lets you record audio and play it back without delay. It converts the analog signal from a microphone or musical instrument to a digital signal you can manipulate on your computer. 

Most audio interfaces let you connect at least a microphone, an instrument, a pair of headphones, and studio monitors to your PC. All modern audio interfaces connect to your PC via a USB cable, but many also support FireWire, Thunderbolt, and PCI connections.

Why Do I Need an Audio Interface?

Not everyone needs an audio interface. However, the device is most useful for users who need high-quality audio, like music creators, podcasters, and game streamers. 

An audio interface has two primary advantages. 

Firstly, you can record sound with better quality since the regular sound card, microphone, and headphone jack on your PC aren’t designed to deliver the best audio experience. They’re fine for enjoying music and attending online meetings, but you can’t expect them to capture noise-free audio or play crystal clear music. 

Secondly, audio interfaces offer more inputs, outputs, and extensive features that give you much more versatility and control over the audio signal. For example, you can connect a guitar or keyboard to your audio interface and use the on-device switches to remove noise or add special effects.  

Do I Need Audio Interface if Not Recording?

All computers include built-in sound cards with decent quality. If you rarely record anything, an audio interface would be an unnecessary expense because it won’t enhance your sound quality. Instead, you should consider investing in better headphones or speakers. 

On the other hand, if you’re an aspiring musician or podcaster, an audio interface lets you capture crisp, noise-free signals that your audience will enjoy. 

What Factors Affect Audio Interface’s Sound Quality?

To understand how an audio interface improves audio quality, you need a bit of technical knowledge about how the device works. 

An audio interface acts as an interpreter between the world analog signals and the digital world of computers. Our vocal cords and musical instruments generate waves that pass through the air to reach our ears. Computers can’t process these physical waves since they only understand zeros and ones. An audio interface can handle both formats and convert them to one another. 

Here’s the analog-to-digital conversion process that takes place inside your audio interface: 

  1. The interface receives the analog signal from an audio source such as a microphone or instrument. 
  2. It amplifies the incoming signal to boost its strength and enhance conversion quality (preamp). 
  3. It takes rapid snapshots of the analog signal and creates a digital replica that the computer can process (conversion). 

Once the audio reaches your computer, you can modify it in any way you like by adding effects, increasing or decreasing the volume, and removing some parts. You can even overlay multiple signals and play around with the tones. The possibilities are endless!

Your audio interface also needs to convert the digital audio on your computer back to an analog sound you can hear through your headphones or speakers. The process is similar to the last one but in reverse.  

As you can see, each step in the conversion process can affect sound quality. However, the effect is more pronounced during the analog-to-digital conversion. 

Here are the most important parameters that impact sound quality:

Microphone Preamplifier

The microphone preamplifier (preamp for short) takes the microphone signal and boosts its level to make it compatible with various audio equipment and software. 

Why is that necessary? 

The reason is that a microphone’s signal is only around 0.001 volts, while most audio equipment works with 1.2-volt signals.  

So, nearly all sound systems, including your audio interface, need a preamp to make the recorded sound audible, which is why most devices come with built-in preamps. 

The circuitry that amplifies your input signal has a massive impact on its quality. A cheap preamp can ruin your signal, while a sophisticated one with various control options can capture all the details without causing any distortions. The difference is more noticeable if you’re making music. 

What’s more, not all preamps work well with all instruments and microphones. Some are specifically designed for instruments like guitars, while others are general-purpose. Specialized preamps tend to be more expensive and could cost up to $2000.  

Analog to Digital Conversion

Once the input signal is amplified, it’s ready to be digitized. The process involves taking successive snapshots of the incoming signal and noting its properties, such as amplitude. 

Two different parameters impact the converted signal’s quality.  

Sample Rate

The sample rate is the number of times we take snapshots of the signal and record its value. It depends on the signal’s frequency. It has to be twice as much as the signal’s frequency if we don’t want to lose any details during conversion. 

Since the human ear can hear frequencies between 20 Hz to 20 kHz, the maximum necessary sampling rate is 40 kHz. However, the industry standard is 44.1 kHz to avoid frequency overlaps. 

Lower sample rates will reduce quality, but higher ones won’t improve it since the extra details are imperceptible. That’s why larger numbers like 96 kHz and 192 kHz are primarily marketing gimmicks! 

Bit Depth

The signal snapshots need to be stored as bits, and this is where the concept of bit depth comes in. It refers to the number of bits you need to store each snapshot. 

At a 44.1-kHz sampling rate, you can store the details using 16 bits, hence the term 16-bit encoding. However, most current standards use a 24-bit encoding, which allows for more details, but its file size is also 50 percent larger. The larger encoding space doesn’t improve sound quality either. 

Watch this video if you’re interested in technical details about the analog-to-digital conversion process:

Latency

Latency refers to the time it takes for the audio signal to enter the audio interface, go through the computer, return to the interface, and move to your speakers or headphones. 

The signal goes through a few layers of processing before being reproduced by the speakers. So, a bit of latency is unavoidable. However, excessive latency makes it hard to work with your signal in real-time because you may hear the input signal a couple of seconds after it’s recorded. 

Audio interfaces use different analog or digital mechanisms to minimize or eliminate latency. These include using faster ports and cables, adding extra processing power, and making their software more efficient.

Cheap vs. Expensive Audio Interface

Audio interfaces can range from below $100 to over $4000. Of course, the more expensive options come with more capabilities, and specifications do matter. But if you’re just starting your audio recording journey, you probably won’t have to spend much more than $100.

Does a Better Audio Interface Affect Sound Quality?

Buying a better audio interface doesn’t necessarily affect sound quality since most modern audio interfaces come with adequate preamps and converters, and they have virtually zero latency. 

So, unless you’re a professional music producer or a sound engineer, the sound quality of a more affordable audio interface won’t be that different from an expensive one. For example, the distortion levels might be a few thousandths of a percent different, but that amount isn’t really audible when you’re recording a podcast or streaming a game. 

The difference becomes only slightly evident if you’re creating music. Higher-end audio interfaces tend to capture more details and produce smoother signals—i.e., less noise and clipping. As a result, the output will sound a bit clearer and more pleasing. 

Here’s an interesting video comparing a $200 interface with a $2000 one with the help of a sound engineer, a DJ, and a regular music fan:

As you can see, even professionals have difficulty differentiating between the output of a cheap audio interface and an expensive one. 

However, that doesn’t mean you should buy the cheapest option. Consider your usage as well as the device’s inputs, outputs, and features. Also, never go over your budget just because you want a cool gadget. You’re not likely to get much extra value from a feature-packed device if you’re not a pro and don’t know how to use it. 

What Factors Affect Audio Interface’s Price?

Sound quality is only one of the factors that determine an audio interface’s price. Here are some of the most significant ones:

Inputs and Outputs

Analog

In general, you need as many inputs as you have audio sources. And it’s better if all those inputs come with preamps. 

If you’re recording one person or a single instrument, such as a guitar, one input is enough. However, a device with two input options lets you record an instrument and a person simultaneously or have a guest on your show if you’re a podcaster. 

Most products on the market come with two to eight inputs, but specialized interfaces offer even more than that. The more inputs and outputs your device has, the more expensive it’ll be. 

Besides the number of inputs, you need to consider their types. Input interfaces fall into three categories:  

  • Instrument-level for a guitar or bass
  • Microphone-level for different types of microphones
  • Line-level for keyboards and external audio hardware such as a mixer

Moving on from the inputs, you need at least a pair of stereo outputs to let you hear the signal via your studio monitors. You also need dedicated headphone outputs for when you want to listen to the audio more carefully. 

If you’re going to share the signal with someone else, you’ll need additional headphone outputs. Finally, pro users should consider audio interfaces that offer separate line outputs, giving them the freedom to connect external hardware to the interface. 

Some audio interfaces have MIDI ports, which let you connect MIDI gear such as a keyboard.  

The video below demonstrates a basic audio interface setup:

Digital

As your studio grows, you may need a more versatile architecture to handle complex projects with a dozen audio sources. So, you’ll need additional channels on your audio interface. The ADAT format is the de facto technology for expanding your audio interface. 

Audio interfaces that include an ADAT port start at around $300, but they can support up to 18 channels once expanded. So, if you’re optimistic about the future, the additional investment may be worth it.  

On-Board DSP

A digital signal processing chip enables you to process the signal inside the audio interface. In other words, the signal won’t have to travel to the PC before you can manipulate it. Here are some of the benefits of DSP: 

  • Eliminates signal latency
  • Frees up your computer CPU so that you’ll have more processing capacity for larger projects
  • Lets you run special plugins and effects embedded in the interface

Depending on the number of cores in the chip, a DSP chip can add up to a few hundred dollars to your audio interface’s price tag. So, it’s not great for beginners. 

Extra Functionality

High-end audio interfaces include various controls that give you more room for creativity. However, the additional freedom will cost you extra. 

For example, the Audient EVO 4 includes two preamps, automatic gain settings, and a loopback function that’s great for podcasting and streaming. 

On the other end of the spectrum, the TASCAM Celesonic US-20×20 can function as a standalone mixer for live shows, and it’s loaded with onboard features for equalizing and compressing your audio. 

Bundled Software

Audio interfaces often come with software that lets you record and process sound—aka a Digital Audio Workstation or DAW. They may also include additional plugins, loops, sound effects, and free subscriptions to audio libraries and relevant platforms.  

For example, the Universal Audio Apollo Twin comes with a free version of the LUNA Recording System, the company’s proprietary environment for recording, editing, and mixing music. The software is packed with valuable features, and there are many additional plugins you can buy. 

These software perks help you get started quickly and unleash your creativity. However, if your audio interface comes with professional software, it’ll most likely cost more, even if the ads say the software is free. 

Other Factors That Affect Quality in the Signal Chain

The audio interface is only one of several factors that determine sound quality. To produce great recordings, you need to pay attention to numerous other details, including the following: 

Instrument and Amplifier Setup

A guitar with dead strings or a piano with a cracked soundboard can’t produce quality sound, even if you have the best audio interface. That doesn’t mean you should buy the most expensive instruments on the market. Instead, you should make sure your instruments are tuned correctly. 

If you’re using an amplifier, check your levels before recording and make sure your input gain is optimal. The meters on your recording software should be in the green zone; otherwise, you risk clipping your signal, which ruins your audio quality.

Recording Environment

Ideally, you should record in an acoustically treated room so that you don’t get an echo when the sound waves hit the surrounding walls. You can achieve this by covering the walls with acoustic panels, such as the Burdurry Acoustic Panels. A rug or sofa can also muffle the sound. 

You also need to put your microphone in a proper position, which requires knowing its polar pattern. You shouldn’t speak or play directly into the microphone. Also, keep the microphone between two to five inches away from the audio source.  

Monitoring System

If you’re serious about recording high-quality audio, you need to make sure it sounds exactly right. Regular computer speakers or earbuds don’t let you hear the recorded sound accurately. So, you may end up publishing low-quality audio without realizing it. 

Recording without a decent monitoring system is like taking pictures with a dirty lens!

Final Thoughts

An audio interface is an essential piece of equipment for any recording environment. It lets you capture high-quality sound and record multiple sources simultaneously. 

However, you don’t need the most expensive audio interface to get the best sound quality. All audio interfaces that cost more than $100 offer acceptable quality. So, it’s not about how much you spend; it’s about finding a suitable device for your specific situation.  

Audio interfaces vary in price because they include different inputs, outputs, and features. Basic devices usually have two inputs and two outputs, while high-end products can feature 20 inputs.