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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Kevin "DJ Wave" Boreing on April 26, 2011, 09:20:47 am

Title: Compressors - In's and Out's, When's and Why's?
Post by: Kevin "DJ Wave" Boreing on April 26, 2011, 09:20:47 am
I've been mixing live sound and DJ environments for nearly 10 years now, running everything from simple small channel mixers to larger and more complex digital systems. One thing that has personally always been a plague on me is compressors.

I understand how and why they work (for the most part), but it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics in the mix. Especially in church settings where the dynamics in a song can go from soft to powerful in short phrasing, I find that relying on the compressors simply takes away from the dynamics of the performance.

Yes it makes it easier to control the peaks especially in the mix, but I usually find myself relying on the individual channel limiters (this being on the i-Live T112) to compress the peaks but not the full compressors to allow a dynamic range, either through the musicians themselves or through live mixing.

I guess my main question is, am I mixing incorrectly by taking this approach? Should I be relying on the full compressor to give the sound an overall "CD recorded" sound like you'd get on most modern recorded music and keep it all the same level? Is my understanding of compression lacking so that I may be looking at this all the wrong way?
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Robert Weston on April 26, 2011, 10:04:08 am
Sounds like maybe the compressor is incorrectly used and/or it's setup incorrectly.  If you want the wide dynamics (let's say the vocals), make sure the threshold of the compressor is set to -0- to start.  Then set the ratio of the compression to something like 4:1.  If the threshold is set below -0-, the compressor will kick in early.  Setting it to -0- or above will allow the dynamics (soft passages) to come through before the compressor starts.   I'm not familiar with your board or the type of compressor you may use, but (for vocals) make sure something like "RMS" is selected and/or something like "soft-knee".

I use a compressor on my vocal subgroup - analog board.  It's setup similar to what I described above.

It's a balancing act....

Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: g'bye, Dick Rees on April 26, 2011, 10:25:43 am
it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics

Considering that it is the function of a compressor to reduce the dynamic range of a signal, I don't know why you should be surprised.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Kevin "DJ Wave" Boreing on April 26, 2011, 10:30:50 am
it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics

Considering that it is the function of a compressor to reduce the dynamic range of a signal, I don't know why you should be surprised.

It's not surprising, it just makes me not want to use much if any compression over a basic limiter function. But if I am understanding or using the compressor incorrectly, then it would be good to know that, as my fundamental understanding of a compressor is to cut dynamics to increase overall volume levels/ cut harshness.

If a board features both separate limiters and expanders, why would you also want to employ a full compressor unless you are trying to go for that "all one level" radio sound.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: g'bye, Dick Rees on April 26, 2011, 10:33:54 am
it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics

Considering that it is the function of a compressor to reduce the dynamic range of a signal, I don't know why you should be surprised.

It's not surprising, it just makes me not want to use much if any compression over a basic limiter function.

So don't use it.  Nobody's putting a gun to your head to make you use it.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Kevin "DJ Wave" Boreing on April 26, 2011, 10:41:28 am
it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics

Considering that it is the function of a compressor to reduce the dynamic range of a signal, I don't know why you should be surprised.

It's not surprising, it just makes me not want to use much if any compression over a basic limiter function.

So don't use it.  Nobody's putting a gun to your head to make you use it.

Sweet, awesome to know inquiries in fundamental techniques of sound mixing and technology are met with such idiotic and rude responses. Bodes well for your professional reputation man, I'll be sure to disregard anything further from you....
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Rafi Singer on April 26, 2011, 11:42:11 am
I've been mixing live sound and DJ environments for nearly 10 years now, running everything from simple small channel mixers to larger and more complex digital systems. One thing that has personally always been a plague on me is compressors.

I understand how and why they work (for the most part), but it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics in the mix. Especially in church settings where the dynamics in a song can go from soft to powerful in short phrasing, I find that relying on the compressors simply takes away from the dynamics of the performance.

Yes it makes it easier to control the peaks especially in the mix, but I usually find myself relying on the individual channel limiters (this being on the i-Live T112) to compress the peaks but not the full compressors to allow a dynamic range, either through the musicians themselves or through live mixing.

I guess my main question is, am I mixing incorrectly by taking this approach? Should I be relying on the full compressor to give the sound an overall "CD recorded" sound like you'd get on most modern recorded music and keep it all the same level? Is my understanding of compression lacking so that I may be looking at this all the wrong way?

Compression is a tool, just like any other processor. There are times to use it and times to not. It seems like you've found a mode of working that is appropriate to your environment and it is one with little or no compression and you know what? That's perfectly fine. In a highly dynamic environment like you've described it seems like a situation where compression would be best applied to control peaks, but you've found a way around that.

A few ways I end up using compression:

- To thicken up a bass that has a ton of attack and not much body
- (In high stage volume situations) to help get the vocals on top of the mix
- Over a subgroup to achieve a bit more bod
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Mac Kerr on April 26, 2011, 12:03:56 pm
So don't use it.  Nobody's putting a gun to your head to make you use it.
Sweet, awesome to know inquiries in fundamental techniques of sound mixing and technology are met with such idiotic and rude responses. Bodes well for your professional reputation man, I'll be sure to disregard anything further from you....

That was the most succinct answer you got. A compressor's only purpose is to reduce the dynamic range. if that sucks the life out of the sound, don't do it. Compressors are vastly overused today because of the ready availability on digital consoles, you don't have to follow the crowd.

Any process you use, whether it is eq, dynamics control, effects, or anything else, should only be used if it gets you closer to the sound you are trying to get. They should not be used as some universal panacea.

Mac
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Greg_Cameron on April 26, 2011, 01:09:03 pm
It's not surprising, it just makes me not want to use much if any compression over a basic limiter function.

I tend to lean in this direction myself. I use a good quality compressor on a vocal subgroup and have it set for very fast attack/release & higher ratio (~10:1) with a relatively high threshold to keep loud vocals from getting out of control without affecting the more average level. As long as your rig has the headroom to go this route, it should work fine. If I'm using a rig that doesn't have that headroom, I might be more inclined to run with a lower threshold, lower ratio, and slower attack/release speeds.

Quote
But if I am understanding or using the compressor incorrectly, then it would be good to know that, as my fundamental understanding of a compressor is to cut dynamics to increase overall volume levels/ cut harshness. If a board features both separate limiters and expanders, why would you also want to employ a full compressor unless you are trying to go for that "all one level" radio sound.

This gets into issues of taste and effect. I tend to use compression pretty sparingly on other things like bass, guitars, and drums. Just enough to keep things under control a bit. Things that tend to get more compression would be really dynamic instruments like horns and certain string instruments that can go from soft to rip your head off loud very quickly. I'll usually throw one on keys as well, especially with acts I'm not familiar with as those levels can jump all over the place & I hate surprises. Usually the audience does too. Nothing wrong with precautionary measures.

Greg
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Mike Harper on April 27, 2011, 10:34:05 am
Especially in church settings where the dynamics in a song can go from soft to powerful in short phrasing, I find that relying on the compressors simply takes away from the dynamics of the performance.

I'm with you I prefer the dynamics, gives the music/vocals more life.  We run compression on each vocal channel and on a couple acoustic guitar channels.  I like to use the compression to help smooth things out a little and still keep most of the dynamics.  mot of my vocal channels have compression ratios set at about 2.5 and thresholds at -6db.  However i have a couple female vocalist that have amazing range, they can distort some lower end dynamic and condenser mics (SM58, EV N/D267 and EV PL84) with no problem with out the preamp on the console clipping, but they also go so soft at times that you can't even hear them.  We've worked with them on mic handling and things but also run compression on them.  Their compressors are set at ratio of 3.5 and a threshold of about -10, I also give them a little make up gain from the compressor for their soft moments to keep preamp gain low to keep from clipping it.  these setting work well for us, keeps good dynamics and also keeps things under control. 

We are running an A&H GL3800 with DBX 1046 compressors.
 
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: g'bye, Dick Rees on April 27, 2011, 10:45:04 am
....i have a couple female vocalist that have amazing range, they can distort some lower end dynamic and condenser mics (SM58, EV N/D267 and EV PL84) with no problem with out the preamp on the console clipping...........  Their compressors are set at ratio of 3.5 and a threshold of about -10, I also give them a little make up gain from the compressor for their soft moments to keep preamp gain low to keep from clipping it.  these setting work well for us, keeps good dynamics and also keeps things under control.

Mike.....

Something is a bit off in your statements here.  You say that these gals are "distorting the mics" , that the pre is "not clipping" and then go on to imply that compressing the signal solves the problem.  If it was actually the mics distorting as you say, then nothing further down the chain (compression or anything else) would remove the distortion.

So I submit to you that it is not the mics that are distorting, but something further down the chain.  By applying compression and then using make up gain you are (as you stated) able to run the channel pre a bit cooler.  So it would appear that although you first say that the pre was not "clipping" there is a good chance that there was some distortion there. 

Another point at which you may have been overloading something would be if you had them routed through a group and you were tickling the summing amp a little hard.

Let the mics off the hook and look at these other points in your signal path.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Mike Harper on April 27, 2011, 12:55:20 pm
Mike.....

Something is a bit off in your statements here.  You say that these gals are "distorting the mics" , that the pre is "not clipping" and then go on to imply that compressing the signal solves the problem.  If it was actually the mics distorting as you say, then nothing further down the chain (compression or anything else) would remove the distortion.

So I submit to you that it is not the mics that are distorting, but something further down the chain.  By applying compression and then using make up gain you are (as you stated) able to run the channel pre a bit cooler.  So it would appear that although you first say that the pre was not "clipping" there is a good chance that there was some distortion there. 

Another point at which you may have been overloading something would be if you had them routed through a group and you were tickling the summing amp a little hard.

Let the mics off the hook and look at these other points in your signal path.

Sorry for the confusion.  They would distort the mics before we added the compressors to the system, we replaced the EV N/D267 mics, with EV N/D767s and RE510s still with no compression at the time and that remedied the distortion.  Later on we added the compression.  hope that makes more sense.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: g'bye, Dick Rees on April 27, 2011, 01:14:17 pm
Mike.....

Something is a bit off in your statements here.  You say that these gals are "distorting the mics" , that the pre is "not clipping" and then go on to imply that compressing the signal solves the problem.  If it was actually the mics distorting as you say, then nothing further down the chain (compression or anything else) would remove the distortion.

So I submit to you that it is not the mics that are distorting, but something further down the chain.  By applying compression and then using make up gain you are (as you stated) able to run the channel pre a bit cooler.  So it would appear that although you first say that the pre was not "clipping" there is a good chance that there was some distortion there. 

Another point at which you may have been overloading something would be if you had them routed through a group and you were tickling the summing amp a little hard.

Let the mics off the hook and look at these other points in your signal path.

Sorry for the confusion.  They would distort the mics before we added the compressors to the system, we replaced the EV N/D267 mics, with EV N/D767s and RE510s still with no compression at the time and that remedied the distortion.  Later on we added the compression.  hope that makes more sense.

Still unclear about what all you've done with mics, compressors and when, but I seriously doubt you can overload those mics.  My money will stay on the change of input gain as the solution whether it was before or after compressors were added.  There are just too many variables and no accurate record of the input levels or how they were achieved.

Glad you got it fixed, though.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Jean-Pierre Coetzee on April 27, 2011, 01:18:49 pm
Especially in church settings where the dynamics in a song can go from soft to powerful in short phrasing, I find that relying on the compressors simply takes away from the dynamics of the performance.

I'm with you I prefer the dynamics, gives the music/vocals more life.  We run compression on each vocal channel and on a couple acoustic guitar channels.  I like to use the compression to help smooth things out a little and still keep most of the dynamics.  mot of my vocal channels have compression ratios set at about 2.5 and thresholds at -6db.  However i have a couple female vocalist that have amazing range, they can distort some lower end dynamic and condenser mics (SM58, EV N/D267 and EV PL84) with no problem with out the preamp on the console clipping, but they also go so soft at times that you can't even hear them.  We've worked with them on mic handling and things but also run compression on them.  Their compressors are set at ratio of 3.5 and a threshold of about -10, I also give them a little make up gain from the compressor for their soft moments to keep preamp gain low to keep from clipping it.  these setting work well for us, keeps good dynamics and also keeps things under control. 

We are running an A&H GL3800 with DBX 1046 compressors.

Another point here, distorting a real sm58 ain't gonna happen off a vocal, had 58s in many high spl situations (2" off beater on kick, picello snare, 100w marshall valve amp cranked to 11) no distortion. Sorry but I cannot believe that the 58 caused problems here.

On the note of compressors, too much compression causes loss of dynamics, my only advice is bring up the threshold and lower the ratio to get more dynamics but that may well make the compressor null and void so your call.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Mac Kerr on April 27, 2011, 02:47:52 pm
On the note of compressors, too much compression causes loss of dynamics, my only advice is bring up the threshold and lower the ratio to get more dynamics but that may well make the compressor null and void so your call.

ANY compression causes loss of dynamics. That is what compression is. The question is whether that loss of dynamics improves the sound, or detracts from it.

Mac
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Tim McCulloch on April 27, 2011, 05:28:31 pm
Considering that it is the function of a compressor to reduce the dynamic range of a signal, I don't know why you should be surprised.


It's not surprising, it just makes me not want to use much if any compression over a basic limiter function.


So don't use it.  Nobody's putting a gun to your head to make you use it.


Sweet, awesome to know inquiries in fundamental techniques of sound mixing and technology are met with such idiotic and rude responses. Bodes well for your professional reputation man, I'll be sure to disregard anything further from you....

You're posting in the big kids sand box.  While most of us are willing to help out, realize that you're not in Kansas anymore, Toto.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Justin Bartlett on April 29, 2011, 03:36:49 pm
I've been mixing live sound and DJ environments for nearly 10 years now, running everything from simple small channel mixers to larger and more complex digital systems. One thing that has personally always been a plague on me is compressors.

I understand how and why they work (for the most part), but it just seems that every time I go to assign either a single channel compressor, or the overall compressor, I start loosing what I feel is the solid sound and dynamics in the mix. Especially in church settings where the dynamics in a song can go from soft to powerful in short phrasing, I find that relying on the compressors simply takes away from the dynamics of the performance.

Yes it makes it easier to control the peaks especially in the mix, but I usually find myself relying on the individual channel limiters (this being on the i-Live T112) to compress the peaks but not the full compressors to allow a dynamic range, either through the musicians themselves or through live mixing.

I guess my main question is, am I mixing incorrectly by taking this approach? Should I be relying on the full compressor to give the sound an overall "CD recorded" sound like you'd get on most modern recorded music and keep it all the same level? Is my understanding of compression lacking so that I may be looking at this all the wrong way?

Do you understand that the limiter is no different from a compressor with a very high ratio setting?  If you want your compressors to be more like limiters, just raise the threshold and increase the ratio until they only engage on peaks.  That essentially gives you a more versatile limiter, and then you can use the de-esser instead of the limiter on your iLive if you want.  Or not; do what works best for your situation..

As others have said/implied - don't use a tool just because it's there.  Use it if it makes things sound better.  Don't use it if it doesn't.
Title: Re: Compressors - In's and Out's, When's and Why's?
Post by: Keith Broughton on April 30, 2011, 07:30:40 am
Quote
realize that you're not in Kansas anymore, Toto.
LOL. ;D
Er sorry, but I found that amusing.

Anyway, if vocalists are using good mic technique (ya...riiiiight), a compressor is usually not required.
However, most vocalists just stand on the mic all the time.
A bit of well sorted compression can help keep that vocal in the mix.
As stated before, try a lower ratio and adjust the threshold until you get the results you are looking for.
I must admit I have never used a limiter to keep vocals in the mix but if it works for you, stick with it.
Sound is not always about what is "right" but about what works.