compressors and limiters in plain english please?? :)

[jdom1023]

i have just really begun recording with my digi 001 and my macintosh G4.

i have a general working knowledge of sound recording. i know that what is being altered is the "signal" which is generated by the instruments or voices we record.

if you could answer this in simple terms i would greatly appreciate it:

1. what i am wondering is....what exactly does a compressor do? why would you want to compress a signal anyway?

i have seen so many compressors and have heard folks talk about compressors and how they sound good...i am just curious what makes compression so crucial to recording. please forgive my ignorance....like i said, i am a newbie to recording.

2. is a limiter the same thing as a compressor? if not, what is the difference between the two?

3. i am wondering, once i learn what a compressor does, which compressor plug ins should i spend my money on?

any and all helps will be greatly appreciated.

God Bless,
jdom1023
[img]images/icons/confused.gif[/img]

[Kickin.da.speaker]

1. A compressor automatically turns down the level when the signal gets too loud (above a preset threshold). The whole point behind compressing a signal is to reduce its dynamic, ie the difference between its quietest passages and its loudest passages.
One good example is listening music in your car. You have the sound of your engine, so you want the quietest passages to be louder than the engine so you can hear them. But then the loud passages can be way too loud, and will distort your audio system, or at the very least hurt your ears. If the audio has been compressed, then there won't be that much difference between the quiet and the loud, and you won't have to reach for the volume knob every 3 seconds (ever tried to listen to classical music on the freeway? [img]images/icons/wink.gif[/img] ).

2. No. A compressor progressively attenuates the level of a signal above a given threshold. A limiter abruptly limits the level of a signal above a given threshold to that precise threshold. Let's try an example:
Your orginal signal is based on a loudness scale going [0,2,4,6,8,10].
A compressor with a ratio of 2 and a threshold of 6 will give you a scale going [0,2,4,6,7,8].
A limiter with a threshold of 6 will give you a scale going [0,2,4,6,6,6].
Basically, a limiter is a compressor with an infinite ratio.

3. Learn with whatever you have. Then I'd say look into the Waves stuff, although I've never heard it myself.

A good link to learn more: http://www.waves.com/htmls/service/t...icks/hutch.htm

I'm sure others will ship in and give you other explanations, more simple or more detailed, but I hope this helped a bit. Good luck!

[where02190]

Comps and limiters are dynamics controllers that you can set to (your own) predeterminted parameters.

Compressor-small dynamic control.

Limiter- large dynamic control.

Hope this is helpful.

[JasonRomney]

My sound professor explained compressors to me this way:

"This little box is a compressor. A compressor is essentially an automatic volume control. Pretend that there is a little man inside there listening to your sound. When it gets too loud, he turns it down. When it gets back to the quiet part, he turns it back up. You can teach him what he should consider as "too loud" (threshold), you can tell him how much he should turn it down when it gets too loud (ratio), you can tell him how quickly to turn it down (attack), and you can tell him how quickly to turn it back up (release)."

Kind of silly but we certainly got the point.

[SoundWrangler]

Imagine the changing dynamic levels within your audio source as a Very Small Person, hopping up & down.
Now, imagine placing a trampoline over that VSP's head. That's a compressor. Tightening the trampoline is like increasing the ratio on a compressor, since it will have less "give" as it elastically (proportionately) prevents the VSP from jumping as high as it would have otherwise. Reducing the height of the trampoline is like lowering a compressor's Threshold - the onset of the level-reducing effect begins sooner.
Now, instead of a trampoline over the VSP's head, imagine a ping-pong table. That's a limiter! [img]images/icons/smile.gif[/img] While you can also adjust the threshold on a limiter (i.e., the height of the ping-pong table), once your dynamic range reaches that threshold it is abruptly stopped (ouch!) & no further travel is possible.

[pk_hat]

Originally posted by JasonRomney:
My sound professor explained compressors to me this way:

"This little box is a compressor. A compressor is essentially an automatic volume control. Pretend that there is a little man inside there listening to your sound. When it gets too loud, he turns it down. When it gets back to the quiet part, he turns it back up. You can teach him what he should consider as "too loud" (threshold), you can tell him how much he should turn it down when it gets too loud (ratio), you can tell him how quickly to turn it down (attack), and you can tell him how quickly to turn it back up (release)."

Kind of silly but we certainly got the point.

<font size="2" face="Verdana, Arial">I think that's about as clear an explanation anyone can hope for. Very well done.

[supercell]

I Love it

Originally posted by JasonRomney:
My sound professor explained compressors to me this way:
"This little box is a compressor. A compressor is essentially an automatic volume control. Pretend that there is a little man inside there listening to your sound. When it gets too loud, he turns it down. When it gets back to the quiet part, he turns it back up. You can teach him what he should consider as "too loud" (threshold), you can tell him how much he should turn it down when it gets too loud (ratio), you can tell him how quickly to turn it down (attack), and you can tell him how quickly to turn it back up (release)."
Kind of silly but we certainly got the point.

[jdom1023]

kickin',

thanks a ton for the insight on compressors and limiters. that makes tons of sense...especially with the example of the radio in the car....great picture of it for me.

thanks again and God bless,
jdom1023

[pk_hat]

and for the holy grail of "how to" sites:

www.studiocovers.com

Enjoy...

[Integrator]

Just remember that while compressing something, like a snare drum will add "punch" to the sound, when you use the make up gain to bring the level back up to a useable level, you are also brining up the noise floor.

So if you crunch TOO hard, of use too much make up gain, you could actually be adding more noise.