Baxter said it nicely.
Compression is a must,if you learn this and EQing right you are mostly covered for serious work.
Though a lot of practice is needed.
Imo the only harder thing is mastering reverbs.
With compression you can do so much,tame peaks,play with transients,increase the energy of an instrument,bus or a mix,etc,etc...
So much you can do with it,producing music becomes really fun when things work for you,not against you.

 

Did you understand what I was talking about? I was talking about what it technically does, not about what it is used for! It's important to understand how easy the concepts of effects really are, to not fall into the trap of thinking they're like magic boxes. It's so much easier to use something if you know its inner workings. So, my contribution is not meant to declare any use mentioned in this thread as false or something like that. It is meant to take away all of the possible applications from somebody who already said that he just can't get the concept. It isn't helpful then to talk about transients, if he not even understands how the device's logic works. And I think I've done a very good job in this regard. Don't expect a beginner to draw a Mona Lisa.

 

I agree with you,beginners should focus on the basics and go from there.

 

I would suggest that sunshine's view is still relevant but he's providing the alternate/real world hardware view of compressors. Obviously the hardware and hardware emulations provide a coloration side-effect to the "mathematical" effect which hadnt been mentioned until he said it, and thats information which is useful AFTER you understand the mathematical affect i.e. (threshold/ratio/attack/release/soft-knee/hard-knee/inverse ratios/gating/limiting/parallel comp). Knowing about the coloration and the limits of the mathematics between each compressor can allow you to make a more informed decision on which compressor to pick and for which use a compressor is suitable for.

Useful reading:
http://www.soundonsound.com/techniques/parallel-compression

 

Last edited: Jul 22, 2016

Mastering compression is a long process, but for newbies a basic grasp of what to do can help shorten that gap. Experimentation alone does not teach anything. Here is my understanding on how compressors operate. This is what I wish someone had told me in 2007. I don't mean to say I've already learned my way up compression, but it is how I understand matters at this point in time:

What It Does
Unlike what it is usually claimed, a compressor is barely used to control volume levels. It is more frequently used to add character or coloration to the source material. In that way, it is more akin to a transient shaper than a gain knob. Varying levels of compression will push a track forward in an in-your-face kind of sound.

Basic Use of Controls

• The input knob adds character. The more you drive it, the more "effect" you hear. Keep it moderate.
• Ratio is how aggressive the compression will be. Higher ratios mean more radical effect.
• Use a fast attack to tame transients and a slow one to maintain the integrity of the source.
• A fast release will prevent the compressor from muddying your signal. A slow one will add sustain. The right balance will pump in consonance with the tempo of your song.
  
• The threshold works in tamdem with the needle or LED indicator. The higher the threshold the more the needle will move. Here's your compression aim: When your input and output levels are right, if you want more or less compression, you'll think of moving the threshold.
• The output knob will compensate for the drop in level caused by the compressor. It may be used as a volume control to make the track louder, though it is wiser to use it to match the volume level when the plugin is bypassed.
• Knee refers to how aggresively the compressor will act upon source material. It can be soft knee (less steep compression curve) or hard (steeper compression curve).

Kinds of Compressors and Use

• FET (1176 style): Great for fast transient material (drums, bass). It helps a track sit well in a mix at moderate level, and it makes it pump or distort musically at extreme levels.
• Optical (LA2A style): Great for everything (especially vocals and bass). It gives a track a lush, softened attack. It is subtle in nature and harder to drive.
• Mu (Fairchild type): Great for clean but somewhat colorful compression even at extreme levels (vocals, mixbus). They are tube-type compressors and have lots of pleasant character. For vocals and acoustic instruments, you can add a fair amount of compression without messing it up. On a mixbus it is used for "massaging" the two track gently.
• VCA (SSL-G, API 2500): Great for the mix bus (mix bus, anything really). VCA compressors are solid-state kind instead of tube emulations. Emulations of these kind of compressors are colorful sounding, but they have a different tone from tube-style plugins.

How to Go about It

• Set up threshold and output to 0 (no gain or reduction) and ratio to 1:1. If there are attack and release controls, set them up to the middle, neutral position (knobs at 12 o'clock).
• If you use the emulation of a classic compressor, set the track output to -18 on a VU meter plugin before the compressor.
• Raise the input until it matches the level of the track with the compressor bypassed.
• Decide on a ratio (1:4 is considered gentle and enough for most uses) and lower the threshold until you see the needle/LED reach -3 to -7.
• If the audio source has lots of fast-peaking transients, move the attack to a fast position. If you want the compressor to ignore fast peaks, move it to a slow position. Tweak to taste.
• The realease knob goes along with the tempo of your track. A fast release will correspond to fast-tempo music. A slow relasease will cause the sustain to linger. Match by ear.
• Some compressors have automatic attack and release (LA2A), determined by the input stage, and others have fixed attack/release values (Fairchild). Yet other compressors have a release control automatable to the BPM of the song (H-Comp). Stick to those if you can't hear attack and release values or if you can't make sense out of them. The effect of the attack/release relationship is subtle anyhow.
  
• Use the output control to compensate for the reduction in level caused by the compressor. Ideally, it should match the level of the signal with the compressor bypassed. You might want to use it to increase gain too, but depending on the compressor used, distrorsion (sometimes not a pleasant one) might be increased.

Final note

• Compressors are tone machines and it takes familiarity to use them, just like an effects processor for guitar. If you have a variety of compressors, you'll have a seasoned sonic palette. Furthermore, compressors like the one in Logic can change type and react like a FET, opto or VCA, for example.
• Low ratios (1:4) and moderate threshold settings (-3 to -7) will cause a compressor to work at its best. Sometimes we need further taming of peaks in a signal or a more radical effect. In such a case, it is better to add a second compressor right after it at moderate levels than to burden one with extreme settings. In this scenario, it is typical to combine types of compressors. For example, a FET type can be used just to catch the highest peaks and prevent clipping, with an Opto compressor right after it to add color to the signal.

 

Last edited: Jul 22, 2016

@tulamide . . Sorry if I ruffled your feathers. Definitely, folks starting out should learn the basics when starting out, and yes, you really gotta walk before you can run. When I read

it put me instantly into reflection mode because I hardly use compression as a means of level management. Your statement felt to me so cut and dry with a unmoving finality to it, and even though your intent was to keep it simple for the OP, that statement in and of itself, even within your context would be (no pun intended) limiting even to a beginner as it wouldn't be telling the whole truth.

I have edited my original post, ridding it of my thoughtless, subjective statement while leaving the educational aspect intact.

 

Hey @superliquidsunshine , I understand you. If I would read the sentence you quoted from me, on its own, I would instantly react. I would mention all the things that were already mentioned in this thread and more. That's why it is so important to not take one sentence out of its context, but leave it in its paragraph. I said, that this is what it technically does. And since I'm programming VSTs in my spare time, I can assure you that it is exactly its functionality, its inner workings. But it's of course not all, that it can be used for! And with the digital era, the possibilities increased with new techniques that weren't possible before (read-ahead, up/down-sampling, etc.)
I think, we're still good? If not, I'll dedicate my next song to you - and use a compressor as a sound-sculpting-device

 

Wow.. I'm so thrilled by all the replies, I will take some time to go over them all, and properly check through what you guys have said.

I really appreciate the help and it means a lot that you have taken your time to share knowledge with me.

Respect brothers and sisters!!!

 

@tulamide.. go ahead and make that song in his honor anyway aite..

that was the most superliquid compressor tutorial I have ever read.... nice one @superliquidsunshine

your words flow like owsley white lightning...