# Explanation of a compressor

Discussion in 'Compressors / Limiters (analog)' started by jdsdj98, Sep 16, 2002.

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1. ### jdsdj98Active Member

Joined:
Jun 8, 2002
Location:
Denver, CO
Not too sure if this post belongs here, but I just thought of something that always gives me trouble when trying to help folks out.

I recently did a couple of live sound gigs for a local band who has decided to bring in a friend of theirs to do sound. They've asked me to come give him a few pointers, as he's being trained "from the ground up." (sounds like a recipe for disaster)

One thing I've always had trouble explaining is how a compressor works. It never ceases to amaze me how many musicians (guitar players, esp., of which i am one) and audio/engineering newbies say, "yeah, a compressor makes things louder, right?" So I say, "well, no and yes" and draw out a graph of input vs. output and blah blah blah and eventually realize that all I really did was confuse them. What's the simplest way anyone has come up with to explain this concept to someone who doesn't understand it?

2. ### mrbeecroftGuest

I don't think it's much good drawing graphs for musicians because they dont think of music the same way as an engineer. Music to them is dots on a page or frets and strings and notes and beats and chords and melodies, not frequency and amplitude and phase and dynamic range stero image etc. One explination I liked (I'm not sure where I heard it) was actually describing limiting.

Imagine that a system is capable of producing a maximum volume of 100%. A guitatist is playing a soft passage which is taking up 80% of the volume. The guitarist then strikes a big meaty power chord which would take system up to 130%. This would break the system. Very bad - speakers will blow and light bulbs will shatter and the ground will split in two. Slot a limiter infront of the system though, and the limiter will automatically turn the volume down to make sure it never exceeds the system's 100% limit. When the power chord rings out, it will turn the volume back up. You can play your soft passages nice and loud, and then strike your big meaty power chords and the limiter will always make sure nothing bad happens. So it doesnt make anything louder, it makes things quieter, but that allows you to keep the average volume higher by riding closer to the maximum level.

I'm sure it was explained to me much better than this. I hope that this was clear enough. Compression is a tricky one. If you can get them to understand limiting, then compression should be easy enough, and limiting is easier to explain as it doesnt involve ratios.

Tom

3. ### RL WallGuest

I'm a musician, and I like it when you explain stuff in terms of pizza and rootbeer.

2 to 1 compression: Shake a can of rootbeer. See, it doesn't get any bigger or smaller, but it feels a lot tighter, doesn't it? :c:

or:

Imagine being able to cram all the flavor of a whole pizza into only one slice! Well, if you get an LA2A or an RNC, bring it over and I will cook you up a Thick Crust Bass Tone you will never forget !

4. ### mrbeecroftGuest

Aaaaaah so all the RNP fuss is over a Really Nice Pizza!