Compressors: How Do They Work?
Most bass players have heard of compressors but not many really know what they do.
They come in several different forms but all serve the same basic function.
Whether it's a cheap stomp-box compressor or a fancy high-end rack mounted version the idea is essentially the same: to compress your bass signal's dynamic range.
The question is, why would you want to do that?
The bass guitar as a very wide sonic footprint that can be hard to control when mixing that signal with other instruments. A compressor can help control the sound more easily by limiting the range of the signal.
In other words, compression makes the louder notes more quiet and the quieter notes louder, balancing the overall sound of the bass. This makes it much easier to mix the bass with the other instruments without losing the powerful low end the bass produces.
This is one reason why so many bass players love tube amps. They have a natural compression effect that increases the harder you push the tubes. In fact all of the early compressors used in studios were tube powered models. That great Motown bass sound is not from an old Ampeg B-15, it's from an old tube compressor plugged direct into the mixing board.
How it's Used
Compression is almost always used on bass to some degree in the studio, however in live situations it's not quite as common. Some bassists like to use it live because it can make your tone sound fatter and punchier while adding sustain. This can help your bass stand out more in the mix.
There are others however that do not like to use compression live because they feel it interferes with their playing dynamics and limits the bass range too much. They also don't like that some compressors will lower the volume and even kill some of the mids from the bass tone. A good quality compressor however won't do this, in fact it should add more punch to your bass sound.
I remember when I first heard about compressor pedals soon after I started playing bass. I was completely obsessed with them for a several years. I've probably gone through at least a dozen different brands of compressor pedals from a simple one knob version to a complex tube powered model with many different setting options.
The main thing I learned from using all those compressors is that a little goes a long way. Over doing it with too much compression can squash your tone and render it lifeless.In fact at this moment I don't even own a compressor, although I am seriously thinking of getting one again soon. While there not for everyone their certainly very useful.
The bottom line is that for electric bass a compressor is a very valuable tool even if you don't use it all the time. It's not as flashy or fun as most effect pedals but in the long run it's far more useful. I would strongly advise that you check one out soon and see if compression is for you.