What is Compression?
You can think of a compressor plug-in as a virtual studio engineer with his hand on the volume knob - if the volume is too loud, he (or she, we don't discriminate!) will turn down the volume by a defined amount, depending on how loud it is.
This results in quieter sounds appearing louder, without increasing the volume of the sounds that are already loud. This is used often on vocals in popular music, where it can considerably increase their clarity.
What can you do with Compression?
There are several controls found on conventional compressors...
Threshold - This is the level in decibels (dB) above which the volume is compressed.
Attack - This is how fast the compressor kicks in after hearing a sound over the threshold - if it is long enough, this can result in really punchy initial hits, then compressing the tail ends of sounds; very useful on percussion.Release - This is how fast the compressor kicks in after hearing a sound under the threshold, increasing the volume to the threshold level.
Soft/Hard Knee - This determines how smooth the compression is - the "Knee", or response curve, is less audibly noticeable when it is smoother, but takes longer to compress the signal as a result.
Gain - This allows for the entire volume of the signal to be increased or decreased.
Some useful techniques
1. Side-Chain Compression
By running another signal into a compressor with a "Side-chain" function, you can achieve a pumping effect used in countless electronic music productions, where a kick drum, for example, will make the rest of the music duck down under it rhythmically as it is played.
2. Over-Compressed drums
Want that insane, loud drum sound? Try a really high ratio, a really low threshold, a really fast attack and as much gain as you can get away with without the sound clipping and distorting. The result? A crazy, noisy sound that is great for more energetic music!
3. Glitchy Percussion
Where compression is conventionally used to bring up the tail end of drum hits, you can do quite the opposite - by reducing the threshold considerably with a high ratio and having a short attack that allows just a fraction of the signal through, you can get some sweet clicky, glitchy percussion!






























