Understand the Proximity Effect in under 5 minutes

The Proximity Effect

This is a useful bit of information for recording in general because it can get more / or be causing more bass in your recordings. You will need to understand The Inverse Square Law.

NOW LETS TRY TO KEEP THIS SIMPLE

This effect only works with directional microphones. (see Polar Patterns) There is a time delay in a sound wave hitting both sides of the diaphragm.

Firstly there are two types of pressure at play and one is being compensated for and the other is not.

1. Frequency Pressure

This is easier to imagine when you see a long, slow bass sine wave and the difference to a high frequency sine wave which has loads of shorter, faster waves. Now imagine a diaphragm and a long slow wave hitting the capsule. The pressure changes are slow and not very intense. Where as 20kHz for example, would have 20,000 waves hitting the capsule in a second. This makes it more intense.

This has to be corrected within the microphone to give an even frequency response in terms of this pressure otherwise you wouldn't get any bass response and everything would sound horrible. Again because, 4kHz would be 8 times as intense as 500Hz. So now the bass frequencies have been boosted and the higher treble frequencies reduced to an even line we move onto the second pressure.

2. Inverse Square Law

This is the rule about how sound is strongest at its source and diminishes over time and space. Now the microphone is already boosting bass and reducing treble because of the frequency pressure differences but the pressure from being closer to the source is not taken into account. See inverse square law for more info

The Proximity Effect

So now the proximity effect happens as a result of the microphone being closer to the source because the microphone takes the increase in pressure as if it was frequency pressure and so boosts the bass frequencies and keeps the treble and higher frequencies down. Therefore leaving you with an increase in bass artificially.

Leave a comment if this helped you.