What is the deal with compressors?

[YanKleber]

Fellows, I just arrived and found a LOT of inputs. Thanks for that! I will read ALL of them properly and carefully. I am recovering from a surgery last Tuesday and soon will be back to recording life! I am excited for finally get the compressor thing!

 

[andrushkiwt]

Fellows, I just arrived and found a LOT of inputs. Thanks for that! I will read ALL of them properly and carefully. I am recovering from a surgery last Tuesday and soon will be back to recording life! I am excited for finally get the compressor thing!

If all that doesn't help, I think we should close down HR

 

[cakewalkKaKed]

I am recovering from a surgery last Tuesday and soon will be back to recording life!

hope you heal quickly and are back on your feet soon

 

[YanKleber]

Hello friends!

Nine days after my surgery I can finally start to give some attention to something other than the recovery itself. This is not my first operation but it is always something epic...

Anyway, after to thoroughly read all the thread I see that compression may be used in several different ways, be for correct problems or to achieve special effects. My current wish is just be able to level signal (specially vocals), so I think that I am doing the first part of the thing correctly with fader automation to make the most of the leveling. Now I am going to try the fine tune with some compressor plugins.

Browsing the web yesterday I found a video at Youtube where the guy shows a curious Waves plugin called "Renaissance Vox" that seems to be a compressor specific for voice. The funny part is that differently from traditional compressors it doesn't have the threshold, attack, etc, controls. I think that maybe it is a compressor for noobies like me? Anyway, in the video he demonstrates the application of the plugin onto a VERY dynamic vocal track with a lot of volume variation and with only ONE tweak he completely leveled it at once. He did it in Sound Forge so it is possible not only hear the sound difference as well to see what the plugin does with the wave form. I looked for this plugin at Waves site and saw that it is kind of cheap ($39). Does anyone knows/use this plugin?

A second thing is that it was said a couple times along the thread that when compressing a vocal track you should do it in a way that keeps the dynamics. It is really puzzling because seems to me that the leveling of a track is exactly the removing of the dynamics. What I am not seeing here?

 

[mjbphotos]

A second thing is that it was said a couple times along the thread that when compressing a vocal track you should do it in a way that keeps the dynamics. It is really puzzling because seems to me that the leveling of a track is exactly the removing of the dynamics. What I am not seeing here?

No, this is correct. If you OVER-compress you will remove all the dynamics - so don't over compress!

 

[bouldersoundguy]

so I think that I am doing the first part of the thing correctly with fader automation to make the most of the leveling.

I would recommend using gain automation rather than fader automation. Both affect the level of the audio but gain is at the beginning of the channel strip while the volume fader is at the end of the channel strip. This way you're manually reducing the dynamics before the signal reaches the compressor, which keeps the compressor from having to work so hard. Then use volume fader automation to fine tune the level for each part of the song.

 

[ashcat_lt]

I think it's more about the timeframe that the dynamics cover. Basically it's inter- vs intra-word dynamics. It is possible to get each word to about the same volume overal without completely destroying the dynamics within the word itself and loosing the transients of the consonants and whatever. It can be the same with other instruments also. Like take a drum track. Maybe one hit is really loud and the next is kinda quiet. So we can compress to bring the loud one down closer to the level of the quiet one, but we don't really want to mess up the internal dynamics of each hit. We want the attack to be as much louder than the sustain as it was, just the whole thing turned down.

This is very much why most folks prefer automation for that sort of leveling - basically because automation can go slower and be more respectful of those short term dynamics while still reducing the longer term dynamic range. There are a couple of ways to get something similar in a more automatic way, but it generally comes down to some form of compression with a relatively long integration time. Plugs like VocalRider and probably that Waves thing do this. I use ReaComp, set Attack and Release to 0, set the RMS time to like 500, and the pre-comp to 250 (actually, I set pre-comp as long as it goes and RMS time to double that, and end up with these numbers), ratio really doesn't need to be very high (often just like 1.1:1, though on vox you can sometimes go heavier), and the threshold and knee get kind if worked until the thing is always doing something when there's anything happening on the track. I usually switch on the auto-makeup just because it can be a lot to make up and the output slider doesn't really go that high. It works so well that it feels like cheating.

Course that's one step in the chain. Before that I usually have an EQ, often pulling out some bottom end, but almost always with and all-pass filter or two to "rotate" or "randomize" the phase of individual frequencies with respect to one another. This tends to make asymmetrical sounds (like many voices) quite a bit more symmetrical, which isn't quite the same thing as compression but can sometimes help make a compressor work more consistently, and just generally make the whole thing a little more full sounding.

Then after the long, slow, gentle leveling comp I'll often have a bit faster and more aggressive one to squish things down a bit more and start to control more if the intra-word dynamics like consonants that pop out or whatever. Sometimes there'll even be two getting progressively faster, with higher ratio but also higher threshold on each.

Which is an important consideration also. When we're talking about plugins - where we're not limited by the number of actually compressors we have in our rack - we can use as many instances of any plugin as necessary. Eventually have to worry about CPU, but... Slap as many damn compressors on there as you need! Most of the time several compressors each doing a little can get better results than one trying to handle it all at once.

Don't know if any of that helps...

 

[bouldersoundguy]

I think it's more about the timeframe that the dynamics cover. Basically it's inter- vs intra-word dynamics. It is possible to get each word to about the same volume overal without completely destroying the dynamics within the word itself and losing the transients of the consonants and whatever. It can be the same with other instruments also.

This accurately describes how I think about and use compression. It's all about time scales and the character of the level changes. Compression can work on a much smaller time scale than is practical to deal with manually, but it is also tied to the signal. When that's what you want it's great, but sometimes you don't want things happening on that small time scale or in a way that's too directly tied to what the signal is doing.

 

[YanKleber]

Thank you all!

I would recommend using gain automation rather than fader automation. Both affect the level of the audio but gain is at the beginning of the channel strip while the volume fader is at the end of the channel strip. This way you're manually reducing the dynamics before the signal reaches the compressor, which keeps the compressor from having to work so hard. Then use volume fader automation to fine tune the level for each part of the song.

In Reaper there is not a gain automation. But it does have a "Volume" and a "Volume Pre-FX" automation. I am using the first one. Should I use the "Volume Pre-FX" instead?

About all the other observations I think that they are too subtle for my level of knowledge in this realm. I am in a stage that I still don't know exactly what I "want" to do in terms of compression and basically I will be happy if I can do the bread-and-butter for now...



Another question... there is any difference other than CPU load between to process the compression in the track in a separate program (like Sound Forge or Audacity) and then re-import it later into the DAW - OR - add the same compressor plugin directly in the DAW track effects chain?

 

[Farview]

Yes, you should use volume pre fx.

The idea is to get the volume in control before sending it to the compressor. That way, the compressor won't have deal with wide dynamic variation and can just handle smoothing stuff out.

For the most part, I don't reach for a compressor to a dress dynamic range issues, I use it for the sound of compression. (Envelope shaping and thickening)

 

[YanKleber]

Yes, you should use volume pre fx.

The idea is to get the volume in control before sending it to the compressor. That way, the compressor won't have deal with wide dynamic variation and can just handle smoothing stuff out.

For the most part, I don't reach for a compressor to a dress dynamic range issues, I use it for the sound of compression. (Envelope shaping and thickening)

Cool, thanks Farview!

 

[ashcat_lt]

I prefer to use the actual Take Volume envelope for things like vocal leveling. Partly because it's right there on the actual take and will move with it. Partly because its adjustments are reflected in the peak display and even though one should never mix with their eyes, the visual reference can help things go a bit quicker. Otherwise, I think it's mostly redundant to pre-FX volume.

The big difference between destructive compression in SoundForge and non-destructive compression in Reaper is that you can change the settings in Reaper any time you want right up until you render the final mix. There's something to be said for just making a decision and committing to it, but it can be nice to have your options open. Reaper can do that destructive style too if you really want or need to free up resources. There are actually several ways to do it, but until you're really sure you've got what you want, it's best to just leave the plugins running realtime.

 

[bouldersoundguy]

It's not just about keeping options open, it's also about hearing the compression in context. Trying to do meaningful compression work on an isolated track would be difficult at best.

Yeah, Take Volume is probably Reaper's name for it.

 

[YanKleber]

I prefer to use the actual Take Volume envelope for things like vocal leveling.

I really have no idea what is this 'Take volume'. The automation options I have for track automation are: volume, pan, width, volume (pre-fx), pan (pre-fx), width (pre-fx) and mute.I am using Reaper v. 4.261.

The big difference between destructive compression in SoundForge and non-destructive compression in Reaper is that you can change the settings in Reaper any time you want right up until you render the final mix.

I got it. So there is not any difference in terms of result. I thought that maybe the destructive compression could be more efficient (or reliable or whatever) because it was not being applied in real time.

Thanks!

 

[Farview]

There is a way of applying volume changes directly to the audio, instead of doing gain automation at the channel strip. That's what he is talking about when he says "take volume". Actually changing the volume of the take.

 

[ashcat_lt]

I really have no idea what is this 'Take volume'. The automation options I have for track automation are: volume, pan, width, volume (pre-fx), pan (pre-fx), width (pre-fx) and mute.I am using Reaper v. 4.261.

Right click on the audio item in the arrange window, I think it's under Take>Show Take Volume Envelope or something like that. Poke around in that context menu and you should find it.

I got it. So there is not any difference in terms of result. I thought that maybe the destructive compression could be more efficient (or reliable or whatever) because it was not being applied in real time.

Thanks!

I think bsg's thing about actually being able to hear the compression in context is an even better reason not to bounce it out to some other program, but it won't make any difference to the actual compression process. Some plugins I guess have a quality modes, but for the most part it's going to be the same either way.

 

[Dicus]

Thanks for this very usefull thread. I learned a lot from it though I did not understand all details.

Hope I'm not breaking in into the thread but this seemed an on topic question to me.

If you use Take Volume would you want to have the volume in all of the song at the same height? I get that you don't want to much of a volume difference so the compressors don't have to work to hard, but aren't you killing some of the vibe if your putting the softer feeling couplets at the same volume as the louder choruses? The song I'm working on now I incline to put the couplets close to the chorus in volume but still somewhat lower. What would be your take on this?

 

[bouldersoundguy]

Thanks for this very usefull thread. I learned a lot from it though I did not understand all details.

Hope I'm not breaking in into the thread but this seemed an on topic question to me.

If you use Take Volume would you want to have the volume in all of the song at the same height? I get that you don't want to much of a volume difference so the compressors don't have to work to hard, but aren't you killing some of the vibe if your putting the softer feeling couplets at the same volume as the louder choruses? The song I'm working on now I incline to put the couplets close to the chorus in volume but still somewhat lower. What would be your take on this?

Use Take Volume to control how the signal drives the compressor, then automate the channel fader to control the level of each line in the mix. It may well be that you don't want to drive the compressor as hard on the softer lines, which may mean you don't have to boost the soft parts with Take Volume just to turn them down again with the channel fader automation. It's really all up to you to decide how you want it to sound.

 

[Dicus]

Course that's one step in the chain. Before that I usually have an EQ, often pulling out some bottom end, but almost always with and all-pass filter or two to "rotate" or "randomize" the phase of individual frequencies with respect to one another. This tends to make asymmetrical sounds (like many voices) quite a bit more symmetrical, which isn't quite the same thing as compression but can sometimes help make a compressor work more consistently, and just generally make the whole thing a little more full sounding.

That sounds really cool. Bu I´m not getting it really. How do I ad one or two all-pass filters to my EQ? I would really like to hear what that does to the vocals of my track. I'm using Reaper with the ReaEQ plug-in.

 

[Dicus]

Use Take Volume to control how the signal drives the compressor, then automate the channel fader to control the level of each line in the mix. It may well be that you don't want to drive the compressor as hard on the softer lines, which may mean you don't have to boost the soft parts with Take Volume just to turn them down again with the channel fader automation. It's really all up to you to decide how you want it to sound.

Thanks! Experimenting with that now. The chorus and couplet now start to sound more even in a way, although the volume is still pretty different! I like it