Computer audio recording requires audio interfaces to primarily convert your analog input sources to digital and vice versa. This piece of equipment is connecting your analog audio inputs like microphones, guitars, keyboard etc convert the analog signals received into digital form and transmit to the DAW running on your computer. Likewise, the digital signals from the computer converted into analog and send the same to outputs that are connected to other devises like powered monitors, amplifiers, recorders, mixing board inputs etc. However, audio interfaces do more than just converting analog to digital and viz. As the audio interface is part of an audio signal chain it will be communicating with devices having digital interfaces like MIDI control surfaces and MIDI keyboards. Another important factor to consider when thinking of an audio interface for your home studio is the capability of the preamp section to capture clean audio. Preamps can influence the nature of the sound captured from your input audio.
What Do You Want to Record?
The ultimate reason why you choose the kind of audio interface best for your home studio is the capability of handling all your present and some of the future audio recording needs. Are you going to record only vocal over a karaoke track? Will you be recording vocal, guitar, other acoustic instruments? Is your primary recording electronic music? How many tracks you would need to record simultaneously? Are you going to work with 5.1 or 7.1 surround sound formats? Answers for all these questions and many more are going to be a major deciding factor for the kind of audio interface you settle in for. The audio interface for a musician creating electronic dance music may be totally different to one used to record a live band. It is always good to keep it simple – buy a piece of equipment that can take care of your present need rather than going for a one with lot of features you may use in the future. Always remember, though audio interface may be the most important piece of equipment in your home recording studio, it will be a part of your audio signal chain and it needs to blend well in the chain and communicate smoothly. Do a compatibility check with the DAW (now a days DAWs are not so specific about the brand of audio interface used) and PC / Mac connections, OS etc.
Audio Interface Inputs and Outputs Count
The number and types of inputs and outputs an audio interface has can directly relate to your recording needs. How many inputs and outputs are ideal for an audio interface depends entirely on your requirement. Typically, audio interfaces have mic, instrument and line level analog inputs. These analog inputs can be either balanced XLR female or ¼” TRS phono sockets or unbalanced ¼” TS phono or RCA sockets. The number of analog inputs you require depends on the number of analog audio channels – like vocals, acoustic guitar, electric guitar, acoustic drums, etc – you are going to record simultaneously. Be aware DAWs can records one track at a time and keep adding new tracks. However, the big trade off is that you end up sending much more time recording tracks. You may need more than one pair of analog outputs on your audio interface to rout the output mixes from your DAW to studio monitors, to headphone amplifies, extra set of monitors and so on. Again, the output connections can be balanced, or unbalanced. Balanced audio connections are preferred due to the noise cancelling technology that avoids any possible disturbances from electromagnetic interfaces. Most audio interfaces come with one or more headphone outputs. For using condenser mics, ensure your audio interface mic inputs have option for providing +48v phantom power.
Another type of typical IN/OUT audio interfaces have is MIDI ports. If you are planning to use MIDI keyboard, MIDI sequencer or MIDI controller, you will require some sort of MIDI connection. MIDI allows you to interconnect several MIDI instruments. Audio interfaces usually come with 5-pin female DIN IN and OUT sockets. However, many modern-day MIDI instruments use an optional USB ports to connect.
You may find additional digital connections like S/PDIF for digital stereo signals or ADAT fiber optic connection capable of passing eight independent channels of digital audio.
Quality Preamps, Sample Rate and Bit Depth
Another deciding factor is the quality of microphone preamps the audio interface has. The primary function of preamp is to increase the gain of weak signals coming from a microphone or similar mic levels outputs. There are basically two versions of preamps – transparent for pure sound the microphone captures and preamps that add ‘color’ to the original sound or in other words enriches timber of your signal.
Sample rate represents the maximum frequency of sound you can record and the bit depth represents the dynamic rage. Standard CD quality audio is recorded in 16bit/44.1 kHz. Recording at higher sample rate it allows higher dynamic range. At 24 bit is considered professional as gives production professionals the range they need to process audio smoothly and can record at 48kHz, 88.2kHz, 96kHz, or even 176.4 or 192kHz.
Audio Interface Computer Connectivity
Computer connectivity is changing very fast and audio interface manufactures have move with the computer technology. That said, what is considered standard - as this article being written – are Thunderbolt, Firewire and USB. Most computers come with USB2 or USB2 whereas firewire is less common and thunderbolt is Mac standard. Thunderbolt is incredibly fast and has the minimum latency. Thunderbolt 3 is about 8 times faster than USB 3. FireWire transfers data at more consistent compared to USB considered slightly more reliable to USB. The advantage of USB is that many interfaces are designed to run on USB power which is an excellent choice for mobile laptop recording.
Latency and Direct Monitoring
Computer Audio Recording suffers from slight delay in playing back what is recorded real time due to analog to digital conversion process. This minute delay is called latency. This will be challenge sometimes for performers as what is recorded is played back with slight but noticeable delay. An audio interface with minimum latency is the preferred one. However, there are several, even entry level, audio interfaces come with ‘direct monitoring’ – routing input signals directly to output channels so that it can be played real-time without any latency. This feature can help performers.
The key to selecting the best audio interface for your home recording studio to define your actual requirements. If you are beginner need only the basic recoding setup, look for audio interface bundles. Many of them come with lighter versions of top-notch DAW.