Improve the impact of your basslines by quickly learning the basics of bass compression

If you've ever visited a professional recording studio, you may have noticed the large amount of outboard equipment that many studios still employ. Nestling alongside a traditional mixing console, there will probably be an abundance of outboard rack units, offering a host of external processing. It’s likely that many of these will be compressors.

There was a time when compressors were only available in hardware, meaning that you would need a single compressor per track - which could feasibly add up to a large number of units.

Today, as we’re operating largely in the plugin-heavy DAW-domain, the landscape has changed significantly. No longer do you have to have an external compressor (although many of us still do) and now you can use as many as you like from within your storehouse of plugins and emulations.

First and foremost, compression is all about dynamic range. The vast majority of compressors offer the same basic set of controls. Some compressors extend a little further, but a basic set of half a dozen controls will likely always be available.

But why is it necessary to compress? Let's suggest that you are working within a conventional song style, with a basic band lineup of drums, bass guitar, guitar, and vocals. While all of these elements would benefit from degrees of compression, there are two elements that will benefit above all others.

Firstly, the vocal part will probably want to sit dynamically above the band elements, and secondly, the bass part provides the perfect foundation for a traditional song format. There is no better way to accentuate this foundation than applying a touch of compression to the bass.

So let’s concentrate specifically on the bass, focussing on appropriate settings and styles of compressor that bring something to the bass party.

Most compressors, whether hardware, software or in pedal-form, typically present some form of metering, either in the style of LEDs or as a needle on a meter.

Despite these being analog elements, it is very common to see a VU meter facsimile on a plugin compressor.

So, let's go through it step-by-step, assuming no prior knowledge.

Apply your chosen compressor plugin to your bass channel (we're using Logic's in-built compressor) and play your track.

The chances are, the compressor metering will not be doing very much at this stage. This is because we need to adjust the control known as Threshold.

Think of this control as being a monitor for the level of the signal entering the compressor circuit. The level has to reach the point of threshold, before the compressor begins to work.

Consequently, reducing the threshold level, should elicit a twitch of the metering, at which point the compressor will begin to do its thing.

Increasing the threshold will probably prevent the compressor from doing anything, unless it is exposed to a very high level of signal.

As a starting point, decrease the threshold point so that the metering starts to twitch.

The meter will probably be displaying something known as Gain Reduction - there may even be a switch to activate this mode.

The greater the movement of the meter, the harder the compressor is beginning to work, but what is it actually doing?

Once your bass signal has extended past the threshold point, it begins to limit the signal.

We can control the amount of compression, which is dictated by the Ratio control.

Working in tandem with the threshold, an increase in the amount of ratio will dictate a greater level of compression, lowering what would be the level of output if the compressor were not in place.

If you are working with some form of synth-bass, in a style such as EDM, you will want a relatively low threshold point, with a relatively high ratio.

This will create a bass track which is as flat as a slab of concrete and the perfect foundation for a commercial EDM track - quick to take effect and heavily compressed!

If, on the other hand, you are working in a more acoustic environment, you may want to increase the level of threshold, and reduce the ratio of compression.

This will elicit a more natural response, which for an acoustic setting is exactly what you want. You don't particularly want to hear what the compressor is doing, you just want to keep your bass under control should the odd rogue peak emerge in the bass part.

You may also find a control described as Make-Up Gain; think of this as a secondary volume control, which allows you to increase or decrease the volume outputted, post compressor circuit. This can be particularly useful - especially for very heavily-compressed bass parts - when you want to balance against a drum part.

There are three other controls that will often present themselves in a compressor environment; firstly, the Knee control dictates how subtly or heavily the compression will take effect at the point of threshold.

A subtler iteration is described as soft-knee compression, although you can increase the Knee control to generate what's known as hard-knee compression. The latter being particularly useful for more electronic forms where more literal application is required.

You should also see Attack and Release controls; the Attack control is used to set the time that it takes for the compression to take effect once the signal reaches the threshold.

Setting this value too low can sound very unnatural, but offset by just a few milliseconds, and it will definitely have a positive effect in most instances.

Similarly, the Release control dictates how long the compression will take to subside. This can be particularly useful for pad-like basses, which might have a prolonged sustain at the end of each note.

You would be forgiven for thinking that all compressors are equal. Unfortunately, they really aren't, as alongside their basic compression duties, they often have a sound of their own.

The 1176 FET compressor, is a particularly agile and impressive unit and plugin for keeping control of the rapid transients that can occur in bass sounds, particularly electric guitar and double bass. This front-end-attack agility will keep any fast bass parts under control, while also colouring the bass signal in a really pleasing way.

Similarly, the LA-2 Compressor is another studio legend which lends itself to bass frequencies. It is well known for being slower off the mark when it comes to handling quick transients.

Hence, it has become very commonplace to use these two compressors in tandem, with the 1176 first, followed by the LA-2.

It's the perfect pairing, and is available in numerous forms virtually from many plugin companies, particularly its architect, Universal Audio. It has a lovely virtual version of both the 1176 and the LA-2A.

You will also note that many included DAW compressors adopt similar descriptions in an attempt to clone these hardware staples.

As with all signal processing, there is no substitute for taking your eyes away from the screen - and using your ears to ascertain what’s needed. As it differs track-to-track.

Zone in on the type of bass sound that you want, and if necessary, don't be afraid to add a back-end EQ after the compression part of the signal chain.

With so much beautiful colouration from the likes of the 1176, it is possible to overcook a signal, and the added bonus of backend EQ, will provide a useful level of control for easing a too-present bottom-end.