For most applications it is enough to play audio via the integrated audio chip on your motherboard. But what if you want to record your guitar, your vocals or another instrument, or play it well? We help you find the perfect audio interface.
Tip 01: Audio Interface
Your PC's motherboard normally contains an audio chip that translates your PC's digital sound into an analog signal for, for example, headphones or external PC speakers. On most motherboards, this audio chip is not of particularly good quality. It is suitable if you occasionally want to play music while typing, but if you want to get really good sound from your PC or get started with recording music yourself, you can't escape better hardware. If you only want a great sound while playing games or listening to Spotify on your PC, then you should pay more attention to the audio specifications when purchasing a motherboard. Some motherboards have pretty good audio chips and digital outputs to connect your PC directly to an amplifier. If you want to make music and record your guitar playing with your PC, for example, you need a device where you can plug in a guitar cable and convert this analog signal into a digital signal for you. Such a device is officially called an audio interface, popularly a sound card. Let's take a look at what an audio interface is all about.
Tip 02: Internal or external
Audio interfaces come in two varieties: internal and external. In the past they were almost only available internally, nowadays most interfaces are external. This is because laptops are powerful enough to serve as a complete music studio, but laptops do not fit such interfaces. Internal audio interfaces still exist as a PCI-e variant, these can of course only be used in desktop PCs. External audio interfaces can have three connections: usb, firewire and thunderbolt. The vast majority of audio interfaces have a USB connection. This is useful because almost all PCs and laptops are equipped with a USB port and the speed of USB is fast enough for audio applications these days. In the past, usb was subordinate to firewire, which is why you still see many audio interfaces with firewire on the marketplace. Thunderbolt is a standard that you mainly find on Apple systems. Because 90 percent of professional music studios run on Macs, you will find many audio interfaces with thunderbolt connections, but mainly for the professional market.
The vast majority of sound cards nowadays have a USB connection Tip 03: Connections
An audio interface always has a few connections. By default, on a simple audio interface you will find at least two audio outputs: one for the left and one for the right channel. In most cases these are two jack outputs (so-called instrument cables), you connect your speakers to these outputs. Sometimes you will find two RCA outputs or XLR connectors instead of jack connections. This last connection can also be found on microphones and is a standard way to connect professional audio equipment. In addition to the two exits, you will often find one or two entrances. These are often XLR connections so that you can easily connect a microphone to them.
Of course you have a USB port (or firewire or thunderbolt) to connect the audio interface to your PC. If you want to DJ with an audio interface, you need four outputs. Two outputs (the left and right channels) to connect to your speakers and two outputs for your headphones to hear your mix before playing it over the speakers. Two? Yes, because headphones are stereo, you also need two outputs for this: one for the left and one for the right. Most interfaces offer headphones as a stereo output so that the left and right channels are combined into one connector. Remember that a stereo headphone jack on an interface is normally just a copy of the two normal audio outputs, if you want to DJ you need two separate channels. The specifications always indicate how many outputs an interface has.
Tip 04: Dac and ad/da
Besides having the connections, sound quality can also be a reason why you want to buy an audio interface. The price of an audio interface varies from a few tens to thousands of euros, in most cases this has to do with the quality of the components. And especially the way in which the interface translates digital to analog and vice versa. You may be familiar with dac boxes from the hi-fi world: these devices translate digital signals into analog signals, to which you can then connect amplifiers and loudspeakers. A similar technique can be found in audio interfaces, only we are talking about ad/da here. Ad/da stands for analog to digital and digital to analog. You often use an audio interface for musical purposes in two directions: your analog signal (microphone, guitar) is converted into a digital signal by the audio interface. In a music program this is digitally processed, the audio interface then sends it out analogously to your speakers. Hence ad/da instead of dac. You cannot determine the quality of the ad/da converters in an audio interface from the specifications, you have to test a device to know how good the converters are.
Sample rate and bit depth
Something you often read when you're delving into audio interfaces is the sample rate and bit depth of a device. The standard sample rate of a CD is 44.1 kHz, of a DVD 48 kHz. Some audio interfaces can handle up to 192 kHz, for hobbyists and semi-pros nonsense, only in professional studios this can be an advantage. The bit depth is important though: 16 bit is standard, but 24 bit (or even 32 bit) is used by most music producers because it is less sensitive to noise in your signal during a recording. The cheapest interfaces only work on 16 bit.
You can connect three types of signals to an audio input of an interfaceTip 05: Audio inputs
There are three different types of signals that you can connect to an audio input of an interface: mic level, line level and instrument level. Mic level is for microphones and has an XLR connection. It is a signal with a low volume and must be amplified by means of a pre-amp (pre-amplifier), a pre-amp is built into an audio interface with an XLR connection. Line level is intended for instruments with high signal levels, such as drum computers, synthesizers and keyboards and can be connected via a jack cable. Instrument level also goes through a jack cable but has a variable signal level. This signal is used by guitars and basses. A line level jack cable is constructed differently than an instrument level jack cable. This is why you will find separate cables for guitars and synthesizers in music stores. If you have an audio interface with one or two audio inputs, these are usually combined jack/xlr inputs. You can plug in an XLR cable from a microphone, but also a jack cable from a synthesizer or a guitar. Your audio interface recognizes whether it contains an XLR cable or a jack cable, but you have to set yourself what kind of jack cable you have plugged in. For this you will find a switch for line or instrument next to the audio input. Some manufacturers indicate an instrument input with a guitar icon.
USB microphone
If you only want to occasionally record your own vocals, you don't necessarily need an audio interface. You can also purchase a USB microphone in this case. A USB microphone already contains an ad converter to convert the analog signal from the microphone to a digital signal. You cannot even connect a USB microphone to an audio interface at all, since an audio interface does not have a USB input. You can of course connect a USB microphone directly to your PC and route the resulting sound to your speakers via an audio interface.
Tip 06: Software
Virtually every audio interface comes with software. This allows you to easily determine which input should have which input volume, or which channel should be routed to which output of the interface. This is especially useful for audio interfaces that have multiple inputs and outputs. Some audio interfaces also have internal effects, such as reverb and echo. Handy, because you don't need a separate program to add reverberation to your voice. These effects are generated by a special DSP (digital signal processor) chip in the audio interface, which is why these effects are also called DSP effects. In the software of an audio interface you also set the sample rate at which the interface should operate and you can save presets for different configurations.
Some audio interfaces also have internal effects such as reverb and echo 48V
In the software or on the front of the interface, you can determine whether the input needs phantom power for an XLR input. Phantom power is also referred to as 48V. The interface now provides some power to the microphone via the attached XLR cable. There are two types of microphones: dynamic microphones and condenser microphones. Microphones of the second category pick up more signals via the diaphragm and almost always need this so-called phantom power to function.
Tip 07: More connections
In addition to the standard inputs and outputs, you will find a lot of other connections on some audio interfaces. The most common is a midi connection, a standard from the early 1980s for connecting drum machines, keyboards and synthesizers to your PC. Adat is also a technology that can be found on many interfaces. This is a digital signal that can send in and out up to eight digital tracks via an optical cable. You can use this to, for example, connect a device with eight pre-amps to your audio interface with one cable. This way you can record entire bands without needing an interface with many inputs. Word clock is intended to synchronize different devices to each other on time. Aes/ebu is a connection for professional purposes, devised by the aes (audio engineering society) and the ebu (european broadcasting union). Yes, that of the Eurovision song contest indeed.
Tip 08: Latency and drivers
If you want to get started recording and mixing instruments, it is important that there is no delay in playing (recording) and playback over an instrument's speakers. In the audio world, such a delay is called latency. The better audio interfaces have minimal latency, cheaper interfaces can have higher latency. But all of them have the property that they have a much lower latency than when you try to record without an audio interface. Every audio interface needs a driver, it is recommended to install the latest driver on your system immediately after purchase. An old driver or one that does not work properly with your version of an operating system is a source of problems such as clicks and higher latency.
Unfortunately for an iPad you need a special mobile interface because of the lightning connector Tip 09: Mobile
If you have a tablet or smartphone and want to make better recordings, you have a lot less choice than if you want to make music with a laptop or desktop PC. The best option for a mobile music studio is an iPad because there are hundreds of music apps in the App Store and iOS is optimized for music applications. In practice, this means that, for example, you are much less affected by latency than with an Android tablet. Unfortunately, the iPad does not use a USB connection but a lightning connector, so you have to rely on special mobile interfaces. Some compact audio interfaces offer you a USB port in addition to a lightning connection, so that you can use the interface with an iPad as well as a PC or Mac. For Android you have a little less choice, although there are more options than a few years ago. Before purchasing, check whether an audio interface is suitable for your type of smartphone or tablet.
Buying tips
We have again selected a few buying tips for you, aimed at the hobby musician. You already have the cheapest audio interface for a few tens, for the most expensive you have to put down a little more than 200 euros.
Behringer U-Phoria UMC22
Price: €35
An audio interface for only 35 euros? Behringer has managed to build a decent interface for this price. The device has two inputs and two outputs and you can connect microphones, guitars and keyboards to it. Of course, some savings have been made, for example, the interface has a maximum quality of 48 kHz/16 bit. However, this is enough if you want to record and mix some stuff at the hobby level.
Focusrite Scarlet Solo 2nd Gen
Price: € 95,-
For less than a hundred euros you have a very cool audio interface from the well-known studio brand Focusrite. The audio interface actually has everything you need if you ever want to record your own guitar playing or vocals. The first audio input is for your microphone, the input has a button to generate phantom power. The second input is intended for guitar, but the switch also allows you to use it for line level devices such as synthesizers. At the back you will find the USB connection and two RCA connections to connect the device to speakers.
Presonus Studio 68
Price: € 239,-
If you really want to get serious about making music, you need an interface with multiple inputs and outputs. This audio interface from Presonus has two audio inputs on the front and two more on the back. So you can connect four instruments (or two stereo instruments) to it. The Studio 68 also has four rear audio outputs in the form of jack connections. All four inputs have a pre-amp, so you can also connect four microphones to them to record drums, for example.
