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We all know the key to getting your songs to sound professional in the modern day is difficult, especially for any of you beginner producers out there, but one way to really get your tracks sounding good is compression. Most of you will know what compression is so if you do just skip down to the types of compressors. For those of you that don't I will quickly explain.
Compression is a way of controlling the dynamic range of a signal. Dynamic range is the difference between the loudest and the quietest parts of an audio signal. A compressor basically reduces the gain of a signal’s loudest parts (above a threshold) in order to make the whole signal louder rather than just having sound peaks. It does this using a few different parameters that can be adjusted in order to get the sound you are wanting.
- The attack parameter controls how long the compressor takes to apply the compression
- The release parameter controls how long the compressor takes to bring the gain of the signal back up after the compression happens.
- The level at which the compression begins being applied, usually measured in dB. Once the level of an audio signal rises above this level the compressor will activate and in turn begin the compression of the signal.
- The amount of compression that will be applied. measured like, 2:1 4:1 10:1 etc. If compressor is set to 2:1, when the level of the audio signal goes above the threshold the compressor will reduce the signal by 2dB for every 1dB over the threshold the signal gets.
If this still doesn't make sense go do some research and come back once you understand it.
Types of compressors:
Compressors themselves aren’t all the same, there is 4 main types of compressors that all work in a slightly different way and using the right compressor for your sound is a crucial part of making it sound good. These compressors can be found in either analogue gear and emulation software, with the latter being the way cheaper and more accessible option. If you don't want to spend any money you can get free software compressors, but to anyone looking at getting into audio production in any of its form, I would definitely recommend Getting a good compressor VST.
So, let’s look at the different types of compressors:
Tube Compressor / Valve Compressor
The Tube compressor (also known as a valve compressor) is probably the oldest type of compressor. The tube compressor has a much slower response than most other types of compressor, meaning the attack and release are much slower than other types. This means that tube compressors are much less versatile than other types of compressor, so why use one? Well the reason that people love tube compressors is because of their unique sound, the tube compressor applies a small amount of second order harmonics to the final gain stage due to the random movement of electrons. The compressor only adds around 0.02% of distortion but our ears pick up on it and actually favour the sound. although it’s not very versatile the sound of the tube amp is second to none. Tube amps are great at providing warmth to drums, vocals and bass.
Optical Compressor (Opto)
An optical compressor is a type of compressor that controls the dynamic range using a light element and an optical cell. as the amplitude of the audio signal increases it makes the light brighter, causing the optical cell to respond by attenuating the signal. The of this light sensitive element basically tells the compressor how much and how quickly to compress the signal.
The reason that people love optical compressors so much is because they all provide their own character. Within an optical compressor there is a lot of different elements that provide different characters. for example, different light sources get brighter and duller at different speeds, also some resistors will act differently dependant on the material there made out of. This difference in material and the behaviour of the material means that the attack and release times aren't linear and will differ from compressor to compressor. Due to a huge range of choices when it comes to the light source and resistors, it means that the sound and behaviour of each compressor can massively differ.
The optical compressor does usually have a slower response than most other types of compressor but that’s not always a bad thing. This behaviour of optical compressors can often result in a very musical compression sound. It’s generally very good for vocals, lead instruments or any other sounds that can use an intangible rounding.
-The FET compressor, which stands for "Field Effect Transistor", Is a compressor that imitates the sound of a tube compressor using a transistor. The FET Compressor uses a feedback design which usually provides it with a smoother sound. FET Compressors are incredibly fast, clean and reliable with a very fast response time which makes them really versatile and good in most situations. Usually these are best used on things like Vocals, Bass, Guitar and Keys, but are also often used to bring out excitement on room mics.
VCA Compressors, which stands for "Voltage Controlled Amplifier", Such as API 2500 or the SSL G Bus are incredibly versatile compressors. They boast a very fast and punchy sound with very low distortion which provides a very 'clean' and transparent sounds. Due to the fast reaction times most mix bus compressors are VCA style. Due to the very low amounts of distortion VCA compressors are incredibly good when pushed to the more extreme settings which also makes it a good option for parallel compression.