A compressor is a piece of equipment that helps with a many situations.  It is used to control the volume of a source without having to constantly adjust the fader.  This unit can only reduce the volume so setting it can take some trial and error.  Correctly setting up and using one can help almost any type of instrument or voice.  Take a look below for some terms you will want to know and some helpful tips.

Terms you will want to know

Threshold

This is the amount of input it takes for the compressor to kick in.

Ratio

This is the amount of input compared to output shown using a colon.  For example a 2:1 ratio will allow 1 dB of audio to pass through for every 2 dB of audio sent to the unit.

Good starting ratios

– Vocal 2:1

– Kick drum or bass guitar  4:1 – 10:1

– Other instruments 2:1 and work up from there as needed

Hard knee

This is a way to describe the compressor kicking in at the set ratio when the threshold is met.  Some compressors have a button for this setting and others you may need to adjust the attack.  It is called this because when it is graphed it looks like a knee.

Attack

How fast the compressor kicks in

Limiter

This is always an extremely high ratio.  Sometimes expressed as high as 30:1 up to infinity:1.  This essentially makes a point that no matter how much sound is put in then it will not get much beyond your set threshold.

Gate

This may be on some compressors.  This acts as a mute. It has it’s own threshold setting and will keep the channel muted until the gate threshold is met.

Tips on Getting Started

Bass player

When mixing with a bass guitar they may already have a compressor.  Many bass players use them to help them when they change from playing steady bass notes to louder slap bass licks.

Vocal

Make sure you don’t set you compressor to where it compresses too much.  When the person stops signing and the compressor allows more sound to go through it again it could cause feedback quickly!

Limiters

Use limiters to help protect speakers from getting damage.

Gates

Good for reducing the extra tones coming from a tom that just resonates for too long.

Compressors are great pieces of equipment and are used by the novice and professional alike.  I have seen some techs use a compressor on just about every channel to help keep volumes at a set range (generally the 80-90 dB range) however this takes skill to achieve a polished result using this technique.  too much compression and the music can sound squashed or unnatural and not enough it just gets out of control.  This technique also costs money to buy the right equipment to do the job.

So get started trying out on your equipment!  Trial and error is the best way to find out how to get them set just right. 

If you don’t have your own equipment call me now and I will help you pick the right compressor for your needs.  910-658-7893.  You can also email me the details and I will send you my recommendation.  ryan@brackmanconsulting.com