The word distortion has different meanings depending on who you ask.
For some, they immediately think of “distorting words or phrases” wherein someone takes what you have said and twists it into something else. For others, they picture a distorted image.
A guitarist sees distortion as an effect for applying to their guitar’s sound. A sound tech sees distortion as a bad sound reflecting a problem in the audio system.
Reasons For Distortion
Audio distortion occurs because:
—A microphone or sound source, like a computer, is being overloaded with sound. Regarding microphones, the microphone can’t handle the volume level which it’s detecting and thus distorts the sound that it’s sending into the sound system. In the case of other sound sources like a computer, you might push the volume level within the computer software past a point which the computer’s hard can handle. Thus, it sends out a distorted sound.
—Loudspeakers are being pushed beyond their limits. Working in live audio production, you might have the occasion of working on equipment not set up to handle loud volumes that your gig requires. Pushing loudspeakers to produce louder sounds than they were meant to produce will lead to a distorted output.
—Faulty equipment. Equipment can fail in a variety of ways. For example, an effects processor could fail and you’d no longer hear any sounds passed through it. However, it could also fail and you’d hear a distorted sound passed out of the processor.
Sound Source Distortion
The most common reason for distortion is an input overload like the microphone overload mentioned above. Mic’ing an instrument, or even a vocal, is more than sticking a microphone right up to the sound source. You have to use the right type of microphone for the job.
You also have to set it up in a way that best captures the sound. A distorted sound can be resolved by placing a greater distance between the sound source and the microphone. Or, it could be resolved by switching the type of microphone.
For example, placing a condenser mic up to a kick drum can cause distortion so you could either swap it for a dynamic microphone or, in the case of large-diaphragm condensers (LDC), move them a few feet away from the microphone. I’m not saying the live environment is the right place for an LDC but you do see how the microphone type and location can stop / prevent distortion. (Check out The Six Types of Kick Drum Microphones.)
Distortion from a sound source, like a computer, usually happens when the sound within the source (computer, CD player, etc.) is driven to a higher output level than what the hardware is able to handle. I find this can easily happen with computers because there are two volume settings which can get changed; the operating system’s volume control and the volume control of the software used to play the sound.
You can even go one level deeper and look at the volume of an individual track in a multi-track audio program. Start by checking the operating system’s volume is at the normal level, then go to the software program and then down into the individual track volume.