FILTER SCIENCE

Look up the word Filtering in a dictionary and you’ll find something like this by way of a definition: ‘pass a liquid, gas, light or sound through a device to remove unwanted material.’ Leaving liquids, gases and light to one side, that’s pretty clear, right? We just need to pass our sounds through a device and we’ll remove the bits we don’t want. But hold on, what device? And how do we know which bits to remove? And if we want nice fat, rich sounds, why would we want to remove any part of them?

It turns out that while that dictionary definition is a useful starting point to understanding the process of filtering, it doesn’t even begin to scratch the surface of working with filters when you’re producing tracks. Yes, filters do indeed remove ‘bits’ of your sound; specifically, groups of frequencies which you deem surplus to requirements. It turns out that focusing the sounds we use by stripping them of frequency content covered by other sounds in a mix actually adds more power to our tracks, as the room we make by filtering one sound can be more effectively used by another. Through this article, we’re going to explore different filter types (the ‘devices’ our dictionary mentioned) to discover that filters are capable of extraordinary things, whether you’re looking for attention-grabbing tricks, or more subtle mix shaping.

A filter under the microscope

Taking a tour of a filter plugin is a great way to understand how filters can be used to sculpt your sounds. Pride of place in any filter plugin is reserved for Cutoff, which acts as the point from which frequency content is removed. This is coupled to another variable control, Filter Mode. Most filters offer different filter types designed to help