Understanding Digital Audio and Midi in The Home Recording Studio

When it comes to producing music in a home studio, one of the most important things you need to understand in regards to editing or signal processing capabilities - is the distinctions between audio and midi. This article will give you an understanding of audio, digital audio, and midi in the home recording studio.

Audio and Midi are very different in what they are capable of from a production standpoint, and their overall nature. Knowing these differences is an essential part of understanding how digital music is produced.

By the time we’re done, you will learn:

• The practical and technical differences between audio, digital audio, and midi.

• Why you need to understand the distinctions.

• How sound gets into and out of your computer.

Audio Audio = sound waves. In audio production audio must be harnessed, manipulated, and edited through tangible electronic equipment. So audio must be turned into an electrical signal before can do anything with it in terms of music production and engineering.

In this case, audio refers to analog signals that are vibrations emitted from a voice, instrument, or any acoustic source. It is transformed into an electrical signal, which, prior to digital conversion and storage onto your computers hard drive is known as an analog signal.

Digital Audio When an analog audio signal is converted through an analog to digital converter it is sampled in large amounts and becomes a stream of binary code. Basically, this means it is a digital representation of the original sound. Think about it like a photograph... When you take a picture you are recording a digital representation of the thing you see. This analogy works perfectly to understand digital audio.

MIDI (Musical Instrument Digital Interface) is a computer-generated data protocol that triggers tones and tells them when to start and stop, how loud to play these tones, (velocity) and other informational commands. It is important to understand that MIDI is not audio, and cannot be processed or edited the same way.

MIDI has been used since it was introduced in 1983. The last couple of decades have made it a standard computer format that is universally compatible. Midi has become very efficient for composing digital music since it uses much less hard-disc space or processing power than audio file formats.

In Practice

Whether you use an internally installed soundcard and a mixer, or an audio interface, or some combination, you are recording acoustic audio through a microphone, or an instrument direct.

That sound is being transformed into binary numbers called digital audio once it passes through your converters. (either standalone, or through your audio interface)

The digital audio that is stored onto your hard disk goes through processing within your daw, which can be written directly to the original sound sample, (destructively edited) or simulated in real-time monitoring without actually changing the original file but will be mixed down and become a part of the new file you create when you bounce the mix to disc.

The sound goes from that file, to the soundcard where it is turned back into analog audio and played through your studio monitors-arriving back at your ears as audio.

This means that your recording technique, signal chain through digital audio conversion, your ear and mixing technique, editing skills, plus the accuracy in your monitoring system, all play an integral role in your ability to produce a professional audio recording.

Now with MIDI... MIDI is just instructional data that commands digital audio to do something. Play, don’t play, how long, how hard, which notes, etc.

Summary

Audio is not midi. Midi is not audio. Repeat that to yourself a few times to let it sink in.

Audio = sound. MIDI = data. Digital Audio = Digital representation of analog audio signal.

MIDI tells digital audio samples what to do.

Audio and midi are different in their inherent nature, form, and the way they can be handled and processed during production in a home recording studio.