Do I need an audio interface for music production?
Yes, you will struggle with a number of issues without one. An audio interface will increase the efficiency and quality of your audio processing, such as audio playback, audio recording, and a decreasing latency time when working with MIDI.
What is an audio interface?
An audio interface is known as a digital-to-analog converter, it converts digital audio information to analog audio information and vice versa. Your computer will process and store your audio as digital data (1’s, and 0’s) and your amplifier and loudspeaker need an analog signal to reproduce the sound wave for you to hear.
You will already have a digital to analogue converter built into your motherboard or even a dedicated sound card to do this processing, however onboard sound cards, or even separate gaming sound cards, are not built to provide the same quality and efficiency for audio input and output, and most certainly won't give you MIDI latency times you will enjoy working with.
Secondly, an audio interface can provide more input and output options, such as multiple microphone inputs and line-level inputs, which can be useful for recording multiple sources at once. Finally, an audio interface can provide additional features, such as phantom power to microphones and preamps which can improve the quality of your recordings and playback.
What is Latency?
Latency is measured in milliseconds (ms) and measures the difference in time between a MIDI trigger and the loudspeaker's audio response. The faster the latency the better the feel and experience of using a MIDI keyboard. A latency time of 20ms or lower is acceptable but 10ms and lower would be even better.
The latency time can also change depending on the computer processing speed (CPU Speed, Hard Drive Speed), the software being used (Operating system and DAW), and your audio settings, such as Sample Rate and Bit Depth.
What is Sample Rate?
As we have learnt, the job of the audio interface is to convert digital to analogue for playback and convert analogue to digital when recording. When recording an analogue signal, snippets of the audio signal are captured and converted to digital data, the sample rate is the measurement of how many data recordings are taken per second. A typical Sample rate is 44.1khz which means every second 44100 data points are captured from the analogue signal and converted to digital.
Higher sample rates capture more information, especially at higher frequencies. A waveform needs to be measured at least twice per cycle for the frequency to be accurately captured in digital data. If the top of our hearing range is 20khz then having a sample rate at 40khz would capture a 20khz waveform twice and accurately represent it digitally. The differences between an audio file recorded or played at 44.1khz and 96khz could be obvious to dogs and cats, but not so much for standard human hearing. The biggest reason for using a higher sample rate is to reduce the artifacts created when digitally processing audio, however most plugins support oversampling which resolves this potential issue.
It is easier to imagine this process when converting an analogue incoming signal to digital, but sample rate also has an impact on the audio output. If your audio settings are set to a higher sample rate, then equally your audio interface will need to convert more data to represent the digital data as an analogue sound wave. The faster the sample rate, the more data is captured and this will give you a more accurate representation of the original analogue sound, however, the more data we capture the more processing power is required and more hard drive space is needed.
Using a higher sample rate could have additional benefits in future-proofing your music, as technology becomes faster and hard drive space becomes cheaper. However, currently, most music is uploaded and listened to at 44.1k on today's listening platforms. Despite this, with the introduction of 4K televisions and advancements in technology, it is reasonable to expect that platforms will incorporate higher sample rates in the future.
What is Bit depth?
Bit depth is the measurement of the dynamic range, which is the difference between the loudest and quietest parts of an audio signal. A higher bit depth means that more detailed volume data can be stored.
The most commonly used bit depth options include 16-bit, 24-bit, 32-bit, and 32-bit float.
- 16-bit audio can store 65,536 possible values per sample and has a dynamic range of around 96 decibels, making it suitable for CD-quality audio.
- 24-bit audio can store 16,777,216 possible values per sample, providing a much wider dynamic range of about 144 decibels, which is ideal for high-resolution audio recording and production.
- 32-bit audio uses a fixed-point representation with over 4 billion possible values per sample, resulting in even greater precision than 24-bit audio. It is commonly used in professional recording and mixing.
- 32-bit floating-point audio uses a floating-point representation, allowing for even greater precision and a near-infinite dynamic range. This format is commonly found in high-end audio workstations as it has the added benefit of stopping your digital signal from clipping.
Tips for buying an Audio Interface
There are several factors to consider when buying an audio interface for music production. These include:
- The number and type of inputs and outputs: Consider how many audio sources you will need to connect to your audio interface and what types of inputs and outputs they require (e.g. microphone, line-level, instrument). Make sure the audio interface you choose has enough inputs and outputs to accommodate your needs.
- The quality of the preamps and converters: The preamps and analog-to-digital converters in an audio interface are important for the sound quality of your recordings. Look for an audio interface with high-quality preamps and converters if you're planning on doing a lot of recording.
- The connectivity options: Consider how you will connect your audio interface to your computer. Most audio interfaces use USB or Firewire, but some newer models also support Thunderbolt or Ethernet connectivity. Make sure the audio interface you choose is compatible with your computer and supports the connectivity options you need.
Overall, it's important to carefully consider your needs and research the different options before buying an audio interface. By finding the right interface, you can ensure you have the right equipment to record and produce high-quality music.