An audio interface proves to be one of the most essential tools in your studio setup, linking your DAW’s internal sound engine and the sound that is emitted from your output (headphones/studio monitors). When you think about the process of music making, you never think about the complexity of certain processes. The role of an audio interface is important, since it converts the digital numbers that occur within your DAW into analogue sound. Today, some of the best audio interface models are the ones that are able to process these signals flawlessly.
Why is this important ? If you don’t have a true sound representation, mistakes will be unavoidable at the mixing stage. Before going into detail about what an audio interface is, it is important to consider the criteria which will allow you to be able to make your choice. To choose an audio interface, you will have to look at different input and output configurations, connection types, formats and consider what you will use the audio interface for (record vocals, mixing, etc.) ?
In this article, we will try to simplify the role of an audio interface in your home studio by thoroughly analysing its characteristics. In the second part, we will give you a list of the best audio interfaces, accompanied by an accurate product description.
What are the properties of an audio interface ?
The primary role of an audio interface is its capacity to allow you to connect your audio equipment (microphones, headphones, studio monitors) to your computer. By doing that, an audio interface converts unreadable analog signals into digital audio information which can be processed by your computer. For this transmission of digital audio to be made, a connection must be used (e.g. Thunderbolt, USB, FireWire, or a special PCI/PCIe card). In turn, the audio interface performs this same process in reverse. It receives digital audio information from your computer and converts it into an analog signal which is the sound that comes out of an output. Most audio interfaces will provide some general connectivity options. These include line-level analog inputs and outputs, one or more microphone preamplifiers, sometimes digital inputs and outputs such as AES, S/PDIF or ADAT.
How to choose the appropriate I/O configuration ?
A basic 1 to 4 channel desktop input configuration is present on the list we constituted for you. Nonetheless, if you are looking for more channels, we have assembled a collection of the best high end audio interfaces on today’s market. If you are a solo guitarist or bedroom music producer you might need 2 channels or more. If you are going to use a condenser mic, your interface preamps will need to be equipped with phantom power* connectivity. In addition, if you’re using instruments, make sure to have an instrument-level input. It is also worth mentioning that line-level inputs and outputs are great for hooking up outboard processors, headphone amplifiers and studio monitors.
What are the different computer connectivity options ?
Thunderbolt connectivity has the advantage of unbelievably high speed and low latency*. Today, it has become the new reference standard for audio interface connectivity. The latest version, Thunderbolt 3, can be found on the newest Macs and is twice as fast as Thunderbolt 2 and more than 8 times faster than USB 3. It is able to support speeds that can go up to 40 Gbps and cable lengths of up to 100 meters (using optical cable). Recently, many high-end interfaces that now support Thunderbolt. Notwithstanding, only Mac users can benefit from this connectivity.
In comparison to USB, the advantage of FireWire is that it transfers data at more consistent rate. This is useful when you’re recording more than one channel at once. If you don’t record several channels at once, there is no real necessity to acquire this connectivity option. A disadvantage could be that there are less interfaces that use FireWire than USB. There are also less computers that come equipped with FireWire ports. For instance, if you own a PC, you might need to install an additional FireWire card.
The advantage of USB connectivity (3.0, 2.0, and 1.1) is that it is the most popular option out there. Hence, there are many interfaces designed to run on USB bus power (rather than an external power supply), which is excellent if you plan to record record with your laptop whenever you’re on the road. The disadvantage is that this option is probably less qualitative than the previous two options.
Next to the 3 options that are mentioned above, there is also a small selection of PC Express and PCMIA card-based interfaces, which are specifically designed for laptops.
What are bit rates ?
Similar to sampling frequency whereby the sample rate determined the precision of the recorded sample, the bit rate determines the magnitude precision and dynamic range of the audio. It accomplishes this by taking periodic measurements of the waveform (i.e: 1 bit = 6 dB which means that 16-bit audio has a total dynamic range of 16 bits * 6 = 96 dB).
Notwithstanding, digital noise floor is pretty high, and the remaining dynamic range is pretty small. If you work at 16-bit, the quieter sections of your audio will tend to be noisy. With 144dB of range, 24-bit audio gives production professionals the range they need to process audio smoothly. Therefore, 24-bit is considered the professional standard and is highly recommended.
An illustration of sound quality and bits.
Best Audio Interfaces On Today’s Market
Focusrite Scarlett Solo (2nd Generation)
On the top of our list comes one of the best options for beginners. The Focusrite Scarlett Solo (2nd generation) comes at a very attractive price and is one of the leading interfaces on the audio interface market. We decided to review the “2i2 – 2 mic Pres” version because it is the most popular and easy to master of all the different versions. Providing 2 inputs (which both accept XLR mic cables and ¼” instruments cables) and 2 outputs, the connectivity options are various and rather complete. Moreover, this audio interface supports 192kHz sampling at 24-bit. For those of you who plan to use microphones in their setup, the 48V phantom power switch is a perfect option. There is also a direct monitor switch for monitoring without latency.
Furthermore, users will be surprised by the low latency and increased sample rates this machine can offer. Sound-wise, the Scarlett Solo is bright and crisp with no noise. Acoustic instruments such as guitars sound clear and natural. The frequency spectrum accounts for clear highs and solid lows. Another advantage with this device is that you get a considerable amount of free (and useful) software. Indeed, the device comes with Softube’s Time and Tone bundle, the Focusrite Red Plugins, and Novation’s Bass Station virtual synthesizer with 2GB of Loopmasters samples. Moreover, you will get 12 creative pack plugins.
Pros & Cons
Native instruments is not an unknown brand in the world of audio equipment. In fact, a lot of quality products have been manufactured by this brand. If MASCHINE (Midi controller) with its fantastic built-in sounds was a stellar product, we also appreciate the dedication of this company to deliver authentic sample libraries. Respecting this logic, the Komplete Audio 6 interface offers a solid 24-bit depth with sample rates of 48kHz. In terms of connectivity, you get 4 analog ins/outs, a digital in/out and a MIDI in/out. The front panel offers 2 mic preamps which are multifunctional jacks. If you use a mic cable, this KOMPLETE Audio 6 will automatically detect mic level signal. If it’s not the case, you’ll need to specify what type of signal line or instrument level using the built in control.
When talking about controls, it is important to indicate that they are solid and seem durable. The monitor section features an analog volume knob which delivers refined level control. There is also a direct monitor function which allows you to use the monitor in low latency (and lets you hear the input before the signal is sent to your computer). On the back panel, you will find the USB port and a very useful 48 volt phantom power, designed for condenser microphones. On a side note, we really appreciated the fact that Native Instruments also decided to feature Komplete elements and Komplete audio 6 with 30 days free trial of Cubase.
Pros & Cons
If the option we mentioned above might be better for some, the older audio interface remains a great option for those of you who are looking for a first audio interface and more specifically for guitarists. Another advantage is that you won’t have to spend as much as for the newer version. When it comes to sound, you won’t be let down either by this relatively old device. The bit depth can be either set to standard (16-bit) or professional (24-bit). Besides, there are a variety of samples rates which are available for use: 48kHz, 88.2kHz, 96kHz, or even 176.4 or 192kHz.
As with the more recent version, the Scarlett Solo already provided a full 48 phantom power on channel 1 at the time. A notable feature of this device is that it provides zero latency monitoring. The nice metal chassis makes the overall design of this elegant audio interface very qualitative. Each channel of this audio interface possesses different functions. For instance, the first channel corresponds to an XLR input (to plug in your mic) and a gain control. Conversely, the second channel features a 6.3 mm input which is intended for instruments (guitar), a gain control and switch to alternate between instrument and line (microphone). Finally, it is worth mentioning that the direct monitor on/off switch allows you to turn on and off zero latency monitoring.
Pros & Cons
The most valuable product on our list is certainly Behringer’s U-PHORIA UMC404HD. “Euphoric” or “ecstatic” are certainly words we would use to describe our reaction when we discovered this audio interface. The connectivity of this machine is very complete, providing 4 inputs / 4 outputs plus 1x MIDI I/O with ultra-low latency to your computer. Moreover, the MIDAS designed Mic Preamplifiers, accompanied by 48V of phantom power are one of the strong aspects of this device. Analog inserts for the use of external effects such as compressors are also available. Another source of satisfaction is the sound quality which goes from 24-Bit to 192 kHz resolution for professional audio quality. The preamps which are featured offer plenty of gain and are warm, smooth and clean.
The multitude of knobs and buttons are intuitive to use. Rather rare, all the preamps can be bus powered. That means that you can power the interface from your laptop. The overall built quality of this machine is very satisfying. All the controls (volume, gain etc..) feel very solid and smooth. If the construction may appear as small, the great build and finish quality compensates for the criticisable size. In addition, a very complete selection of downloads and softwares are comprised. The bottom line is that if you need a couple of extra preamps, which are unavailable on other inexpensive interfaces which usually only provide two, the Behringer UMC404HD is an unquestionably righteous choice.
Aimed at Apple users (Mac, iPad) and beginners, the Focusrite iTrack Solo is a great choice when you start your music production journey. Entirely encased in aluminium, one gets the impression of a quality which lacks with other audio interfaces (i.e: the all-plastic M-Audio Fast Track). The Build quality is solid. Controls feel tight, precise and provide a satisfying experience for every user. The front panel features a microphone input (XLR), an instrument input (¼’ unbalanced), 2 gain knobs, 2 gain halo signal indicators, a 48V phantom power switch, a direct monitor switch, and a large monitor level dial (controls headphone and line level outputs). On the rear panel, you will get 2 unbalanced monitor outputs, a device link port (to connect iTrack Solo to iPad), a USB 2.0 Port.
Things that this interface won’t provide are dual mic preamps or stereo inputs . If you need those, you’ll have to look at a more expensive interface. Sound-wise the device doesn’t really match its competitors but provides a generally honest and overall reliable sound representation. Softwares that are included are Ableton Live Lite 8, Focusrite’s Scarlett plug-in effects suite, 1GB of royalty-free Loopmasters and a copy of Novation Bass Station. If it’s not a product for all music producers, it is important to notice that the Focusrite mic preamp sound clean, warm. To conclude, the direct Monitor button lets you record and monitor audio directly, so there’s no comb-filtering effect from the latency.
Pros & Cons
Our final choice is the PreSonus AudioBox USB. We decided to feature it because we believe that it is one of the best audio interface for any beginner in the world of music production/recording. The amount of features that are offered at this price range make it a very complete device. What we appreciate is that the sober and elegant design is perfectly associated with the solid built quality of the hardware. The hardware components cover all the requirements which are necessary for music production. You will get 2 dual-purpose front-panel input channels, possessing both high-quality mic preamplifiers. There are also 2 combo mic/instrument inputs which are included. A particular feature is the individual channel-trim control displaying a 0 to +35 dBu mic gain range.
Once again, the very popular 48V phantom power switch for condenser microphones is provided. With the AudioBox USB 96, the mixer control blends the input signal with the computer playback stream to allow zero-latency monitoring. Other connectivity options include the USB 2.0 port, 2 combo XLR/¼” mic/instrument inputs, 2 balanced ¼” main (L/R) line outputs 1 stereo ¼” headphone output and a MIDI in/out. When it comes to sound, the PreSonus’ preamps are quite transparent, making them versatile with all musical elements (vocals, guitars, drums). The featured softwares (Presonus DAW) and the Studio One 3 Artist are very helpful and complete for any user. Nevertheless, if you already have a DAW you won’t really need them.
Pros & Cons
What does sample rate mean ?
Each sample is a digital snapshot of the captured audio. The CD standard (44.1kHz) takes 44,100 digital pictures of the incoming audio every second. Digital to analog conversion only needs two samples (the top and the bottom) of a wave form to generate a frequency. Therefore, the 44.1kHz sample rate is theoretically capable of reproducing frequencies as high as 22.05 kHz.
The uppermost range of human hearing (young females) is 20kHz, so technically, 44.1kHz is more than enough to capture and reproduce every sound you can hear. However, there are additional considerations that may or may not suggest higher sample rates capture valuable information. That’s why most audio professionals choose to work with 48kHz, 88.2kHz, 96kHz, or even 176.4 or 192kHz.
Furthermore, it is necessary to note down that higher sample rates and bit depths consume more disk space and limit your track count. Hence, you’ll need to work within the limits of your equipment. Last but not least, the most important thing to remember about sample rate and bit depth is that they are much less significant than the quality of the digital converters you use !
How can we define converter quality ?
Analog to digital (A/D), and digital to analog (D/A) converters are the devices that convert the incoming analog audio signals into digital data, and the digital data from the computer back into analog audio output signals. Just as important as bit rates and sampling depth, the quality and accuracy of the converters in your interface is quintessential. This is where a gap of quality can be visible between two different audio interfaces. As a consequence, more important price tags generally equate to better quality converters.
What is latency ?
A very important notion which you will come across at numerous times when using your DAW interface is latency. Latency is the amount of time it takes for a signal to go through your audio interface, get processed by the computer and then sent back to the unit where your headphones are connected. The audio chain works as follows:
Audio Interface > CPU > Audio Interface > Headphones
We went over the best possible audio interfaces you can find on the market. As you noticed from our analysis, there is no best audio interface. There will always be an advantage from one audio interface to another. However, always remember to consider your needs. What is the primary purpose of your purchase ? We have mentioned that the audio interface is an important tool to have in your home studio, therefore we would advise you to consider well all the options that are available, and to never underestimate the importance of an audio interface in your home setup. Finally, this article was meant to focus on the best audio interfaces without really going into detail about their price range. Nonetheless, as this is an article which was aimed at beginners, we tried to retain the price tag in the lower ranger whilst going through the main functions of this very important device.
Latency*: Latency refers to a short period of delay (usually measured in milliseconds) between when an audio signal enters and when it emerges from a system. (Source: wikipedia)