Compression 101

so i just got home from a digital recording class im taking and we just went over compression. i understand that compression effects the dynamic range of a sound, bringing down the highs, and raising the lows depending on ratio and threshold. i get the idea of attack and release as well, however, i dont understand its practical uses in production, what it does sonically, and when to use it properly. ima try to be as articulate as possible..

1) my question is, is what is the sonic aesthetic of compressing something? in class, we bussed 5 drum track mics to an auxiliary track, where we then compressed. before compression, the kickdrum was a bit muddy and it's velocity was not consistent. after compression, the compression made the overall beat feel a bit more thuddy and hit harder (if thats the right word to use). what was the purpose of this?

2) i realized that the point of the aux track is so all the drums have the same compression settings, making things neater. in hiphop production, do we compress individual tracks with diff settings, or have the same compressor settings for all the drum tracks like my lecturer demonstrated in class?

3) when do YOU use compression in producing your beats?


good looks mpc-fam, i understand by the book what compression does, but i still dont get its real life purpose, sonic-effect, and when it is necessary to use it for hip hop production!

tunnelno5 wrote:so i just got home from a digital recording class im taking and we just went over compression. i understand that compression effects the dynamic range of a sound, bringing down the highs, and raising the lows depending on ratio and threshold. i get the idea of attack and release as well, however, i dont understand its practical uses in production, what it does sonically, and when to use it properly. ima try to be as articulate as possible..

1) my question is, is what is the sonic aesthetic of compressing something? in class, we bussed 5 drum track mics to an auxiliary track, where we then compressed. before compression, the kickdrum was a bit muddy and it's velocity was not consistent. after compression, the compression made the overall beat feel a bit more thuddy and hit harder (if thats the right word to use). what was the purpose of this?

2) i realized that the point of the aux track is so all the drums have the same compression settings, making things neater. in hiphop production, do we compress individual tracks with diff settings, or have the same compressor settings for all the drum tracks like my lecturer demonstrated in class?

3) when do YOU use compression in producing your beats?


good looks mpc-fam, i understand by the book what compression does, but i still dont get its real life purpose, sonic-effect, and when it is necessary to use it for hip hop production!

Basically you are reducing the dynamic range of the signal. Lowering the peaks (threshold) and then raising the overall level. This is used for a few things. 1) being to gain more overall constant level of the signal. 2) when reducing the dynamic range you are 'tightening' up the signal.

As far as bussing is concerned, yes you want to be able to apply different compression setting to individual elements of your material. (at least in the mixing stages.) (Eventually one might compress the stereo buss (2 track). And then of course heavy compression aka limiting during the mastering stages. (20:1 or greater).

Busses are not only for organization but also to eliminate using to many voices and help not bogg up the CPU. Not to mention being able to ultimate control over dry and wet signals.

this could go on forever. Just remember at the end of the day there are only a few knobs / buttons on a typical compressor. Truly understand what is going on with each and you will experiment your way to greatness. Once you rise from the smoke look into multi band compressors. Thats where all the magic happens!!

Cheers and happy recording!

becareful with compression though! Alot of people forget that it all starts with your source. You will be raising the noise floor of the signal so where and how your source was recorded places a big role. Just something to keep in mind.

On a side note, one thing I like to do is compress pre EQ. Some people would argue but hey thats the name of the game.

Think of it this way. you are "flattening" the amplitude of the signal.

you are saying: (at a compressor setting of 2:1 ratio.) Everything above this level (wherever you set the threshold) I want to cut 2db off for every 1db it goes past it.

and I want it to start doing this compression exactly this many milliseconds after the signal does. (the attack)

and once the signal stops, I want it to go back to open (uncompressed) this quickly (the release)

if that made any sense

:relights joint:



youll go thru fazes too. overcompressing the crap out of everything, and undercompressing.

tunnelno5 wrote:so i just got home from a digital recording class im taking and we just went over compression. i understand that compression effects the dynamic range of a sound, bringing down the highs, and raising the lows

No it isn't frequency dependent (unless you set up a sidechain to an EQ). So talking about highs and lows is irrelevant.

1) my question is, is what is the sonic aesthetic of compressing something? in class, we bussed 5 drum track mics to an auxiliary track, where we then compressed. before compression, the kickdrum was a bit muddy and it's velocity was not consistent. after compression, the compression made the overall beat feel a bit more thuddy and hit harder (if thats the right word to use). what was the purpose of this?

A compressor is an automatic fader dependent on 4 main elements: Ratio, Threshold, Attack, and Release. However, a compressor can also be used as an effect. When used to achieve the former, the compressor shuold be transparent. When used to achieve the latter, the compressor will introduce audible artifacts (pumping, waning).

2) i realized that the point of the aux track is so all the drums have the same compression settings, making things neater. in hiphop production, do we compress individual tracks with diff settings, or have the same compressor settings for all the drum tracks like my lecturer demonstrated in class?

The point about bussing your drum tracks, is to have them all compressed by the same values and same plug in / outboard processor. This is also practical if you only have one compressor to work with. Personally, I compress different elements and SEND to a bus (note, NOT re-assign Output to buss). This is called parallel compression or, New York compression. It lets you mix the comrpessed signal with the dry signal.

3) when do YOU use compression in producing your beats?

On separate instruments: when I need to tame transients and emphasize (or de-emphasise) attack and release.

On mix buss or aux channel: when I want to "gel" the mix.

The Grublet wrote:Think of it this way. you are "flattening" the amplitude of the signal.

you are saying: (at a compressor setting of 2:1 ratio.) Everything above this level (wherever you set the threshold) I want to cut 2db off for every 1db it goes past it.

and I want it to start doing this compression exactly this many milliseconds after the signal does. (the attack)

and once the signal stops, I want it to go back to open (uncompressed) this quickly (the release)

if that made any sense

:relights joint:
youll go thru fazes too. overcompressing the **** out of everything, and undercompressing.

excellent post.

zippertafari wrote:

The Grublet wrote:Think of it this way. you are "flattening" the amplitude of the signal.

you are saying: (at a compressor setting of 2:1 ratio.) Everything above this level (wherever you set the threshold) I want to cut 2db off for every 1db it goes past it.

and I want it to start doing this compression exactly this many milliseconds after the signal does. (the attack)

and once the signal stops, I want it to go back to open (uncompressed) this quickly (the release)

if that made any sense

:relights joint:
youll go thru fazes too. overcompressing the **** out of everything, and undercompressing.

excellent post.

thats the best anyone has ever put it... plain and simple.

Word^^^^^

Very informative actually.

Shostakovich wrote:audible artifacts (pumping, waning).

could you explain what waning is?

tunnelno5 wrote:
2) i realized that the point of the aux track is so all the drums have the same compression settings, making things neater. in hiphop production, do we compress individual tracks with diff settings, or have the same compressor settings for all the drum tracks like my lecturer demonstrated in class?

i think you should also keep in mind that for example having five drum mics sent to one compressor vs having them sent to five compressors with the same setting will yield different results

AntonPD wrote:

Shostakovich wrote:audible artifacts (pumping, waning).

could you explain what waning is?

I was taking the piss.

hmm ill assume its a language related joke, cause i dont get it

thanks for all the help guys, many different answers on what compression is.

1) so what i got from this is that compressors are used to get a more uniform wav from a not so uniform wav whether it be a not so great player. is it safe to say that compression usually makes something sound "tighter"?



2) i can see a more practical use for compressing live recorded instruments, but for the majority of us hip hop heads who sample, aren't the sample sources ie) drum breaks usually already compressed when it was recorded?


3) it seems like many people veer away from compression. if i need a kick to punch out more in a mix, im assuming i should get the levels right in the mixer first and/or a proper EQ rather than compress it?? am i headed in the right direction?


i understand how a compressor would be helpful for a long vocal line or a bar of any instrument, but if i chop in oneshots, how noticable is a compression since the wav is so short (because its a one shot). ?


maybe if any of you headz can post drum tracks compressed, and not compressed , then i'd get the sonic picture. it'd be much appreciated! good looks mpc-fam

Treat the compressor like an eq. Less is more. But using it on drums is the truth. Listen to dr.dres drums. He compresses,layets,compresses,layers, eq's. They sound like 0 bd when there only -14 . It prevents the kick clouding the song also. Eq is short for louder. We all know louder leads to distortion. Use the brauer method. And all you people that say not to.. haHaha. Wow. Try paralel compression, or multibuss. The brauer method is named after probably the best enginer to day.

Compression

Watch the Primer, it's free and hopefully will be of help.

Btw, you don't cut by 2dB for every 1dB that goes in (example given earlier). A ratio of 2:1 means that for every 2dBs that goes in 1dB comes out.