How to set up bus compression before mix

dilithium85

I'm having trouble understanding how to route all my recorded tracks into a compression bus track first, then send them out individually for further processing. I'm using reaper.
This is a preferred method rathe compress at the end which changes level and frequency response of the mix

Danny1969

Generally you use compressors as an insert ... so stick a compressor on any track you think needs taming a bit. This is series compression .. all the signal travels through it. 

For parallel compression, popular for drums create an aux bus track and send some things to that. This is parallel compression, some of the signal travels through it. So this is just like an aux track with reverb or delay but has a compressor insert on it instead

For master bus compression, stick a compressor on the master bus if you want but generally that's a mastering thing really. 

dilithium85

I want to make sure I'm mixing the track through, or after, a compressor so I having an salted sound when do the final touches

Musicwolf

dilithium85 said:

route all my recorded tracks into a compression bus track first, then send them out individually for further processing.

Basically, you can't.

If you send all of your tracks to a bus, and apply compression, you can't then split them back out.  What you can do is;

a) Apply compression to individual tracks (i.e. several compressors, one per track)

b) Use parallel compression where you split the signal and send some to the compression bus (this will be mixed and you can't later split this up into individual tracks) and part is unprocessed (so you can still process this portion of the tracks individually).

If you go route a) then, as Danny said, the compressor is normally used as an insert effect, you don't need to set up a bus.

Macca_25387

Add a compressor onto your master bus as mentioned above is the answer. You can’t route them back out, but you can add extra compression on those single/ group channels going into the master bus should you want to. 

digitalkettle

dilithium85 said:

I want to make sure I'm mixing the track through, or after, a compressor so I having an salted sound when do the final touches

It’s not mandatory to put a compressor on a track: ask yourself what you are trying to change first.

 Most of the advice above is worth taking note of. Comp on the master bus is probably not what you’re after: arguably, you’re starting to master rather than mix at that point…you might fix one thing at the expense of something else.

Once you’re done mixing, you can bring up the overall level by putting a limiter on the master bus. Or a combination of comp/eq/limiter…a quick and dirty diy ‘mastering’ approach

Stuckfast

I agree that you shouldn't put a compressor on anything unless there's a specific reason for doing it. What are you trying to achieve? Even out the dynamics? Alter the feel? Darken the tone in a different way from EQ? Bring up low-level detail? Stop a few rogue peaks from jumping out of the mix? All of those are possible with compression but will require quite different settings.

I don't think I would agree that putting a compressor on the master bus is necessarily something that should be left to mastering, though. It can certainly be a mix choice and if you're doing more than a dB or two of gain reduction it will change the mix balance so you definitely want to work with it in place from a fairly early stage.

dilithium85

I have mixed a lot before. It's just a technique I keep hearing people discuss which is applying compression on the whole track so It 'glues' together. If that makes sense 

Danny1969

That's master bus compression ... yes it can kinda glue things together ... putting a reverb on with the mix level only set about 7% does a similar trick. In a real studio there's the room sound that gets into ever instrument and you can hear they were recorded in the same space. Putting a tiny touch of verb on the master bus does a similar trick. 

For checking mixes in the car I put a compressor and limiter on the master bus myself

Remove the compressor though if you send it out for mastering as you can't take compression off a 2 track master 

monquixote

When I'm doing something where it's not a band in a room and everything is individually multitracked it can sound like it's just a bunch of random sounds and not a cohesive piece of music. 

As a result I would typically do a few things to glue the bits together which would usually be:
Bussing similar things like guitars, synths or percussion that are doing a similar job and then putting a "glue" compressor or saturator (or tape sim which does both) to stick everything together a bit. 

Have a room reverb on a send that I would send a little bit of everything to just so it sounds more like it all exists in the same space (putting on the master with a low mix as Danny suggests would do the same thing) 

PolarityMan

Musicwolf said:

dilithium85 said:

route all my recorded tracks into a compression bus track first, then send them out individually for further processing.

Basically, you can't.

If you send all of your tracks to a bus, and apply compression, you can't then split them back out.  What you can do is;

a) Apply compression to individual tracks (i.e. several compressors, one per track)

b) Use parallel compression where you split the signal and send some to the compression bus (this will be mixed and you can't later split this up into individual tracks) and part is unprocessed (so you can still process this portion of the tracks individually).

If you go route a) then, as Danny said, the compressor is normally used as an insert effect, you don't need to set up a bus.

I actually tried to file a patent for a plugin that would let you do that. My company didnt want to back it though (as its not business related) but I think they did a defensive publication. 

PolarityMan

digitalkettle said:

 Most of the advice above is worth taking note of. Comp on the master bus is probably not what you’re after: arguably, you’re starting to master rather than mix at that point…

I dunno there's a bit of a trend towards top down mixing so this might be what he actually means. Course it would be pretty mad if that was the only compression stage. 

mike257

dilithium85 said:

I have mixed a lot before. It's just a technique I keep hearing people discuss which is applying compression on the whole track so It 'glues' together. If that makes sense 

Yep, bus compression is a popular thing, I think you're just misunderstanding how it's applied. You have your individual channels that you process as you wish, and then instead of routing them directly to the master bus, you route them to as many buses.as you wish to group things in to, and then those buses are routed to the master. 

To do this in Reaper, add an empty track for each bus you wish to create, and make sure they're routed to the Master bus. On each channel you wish to send for bus processing, go to the routing, remove the send to the Master, and add a send to your bus track, post fader and set to 0dB. 

When I'm structuring a show file for a live mix, I'll usually have two drum buses - one with all the drum mics that'll get some mild compression to tie things together and catch any big peaks, and a second "crush" bus that just has the close miked kick, snare and toms (no cymbal spot mics or overheads) and gets slammed with heavy compression, which I'll mix in to taste to add weight and sustain. If I've got multiple bass channels, they'll get a group, as will guitars, and then a vocal group too. Compression across these groups will help the individual sources sit together as a cohesive whole. On dense groups or tracks that clash with the vocal, I'll often use a multiband compressor externally keyed from my vocal group, and just dip a couple of dB in the 1-2kHz range when the vocal is active to make a little more space in the mix for vocal clarity too. 

You can, as others have said, also add some compression at the master bus if you wish. 

The trick is not to overdo it at any stage (unless that sonic result is what you're going for!), but to use each stage of compression with a specific dynamic or tonal purpose in mind. Subtle use at each stage (channel, bus, master) can give you a tight, controlled and cohesive mix without sacrificing dynamic range and the expression in the performances.