What are the purposes for "buses" and "sends"?

C

ColdToTheTouch

New member
Anytime I looked up how to do something, and it mentions any type of "busing" or "sends" i get totally lost. I think i have a tiny basic idea of what they might be used for, but then again I dont think I have the slightest idea. i coujld spend hours googling it or youtubing it, but I never get the answers I need, until I come to HR. What are the main uses/purposes, and what is the difference between adding FX, or any other type of processing directly to the channel, and busing it? and what is a sidechain? is that just a group of FX linked to a specific channel, or is that a group of FX, lets say...compression, EQ, and limiter that a few channels can be linked to? i apologize if I dont make any sense or Im asking such ridiculous question. like i said I could go google this, but I like the support I get form all you people here at HR!!!
 
Well, you can set one reverb unit up. Then route the channels you want to that single reverb unit, and you can adjust how much you are sending to the reverb. That way you can use the same effect without having an effect on all the channels, eating up unneccesary processing.

Also, some units are designed for use as sends, such as reverb. You can use them as inserts, but that's not their intention.
 
Busses / groups -- Like a group on a bus. You can send all your drums to one group (buss) and then control the overall level with one fader. You can also insert a light compressor on that buss to give it a little 'pump' ---

Sends -- You're sending a copy of a signal somewhere else. As mentioned, for additive effects (spatial, modulative, time-based). During tracking, those would be for your headphone mixes.

Insert -- When you want that entire signal to be affected -- usually EQ, compression, noise reduction, etc.

Sidechain -- Using one signal to affect another... You can use the kick drum to trigger the compression of the bass guitar for example. You can use a signal from a group to affect another group. You might have a vocal signal triggering a compressor on the guitars on a rock song. Vocal gets louder, moves the guitars back a bit. Vocal goes away, guitars come back up (we're talking a dB or so in most cases here, but the effect can be fairly dramatic, such as in a radio broadcast where the voice might duck down a music bed 6-10dB during a commercial).
 
"Bus" refers to any point in the signal path where multiple signals can be combined into a single signal.

A send is a point in a channel's signal path that the signal is split and directed to some other path, without interrupting the channel's normal path to the main mix bus. Generally this is used for a parallel effects loop to add one reverb to several channels. The reverb is set to 100% effect (none of the original signal) and the output of the effects bus is mixed with the original signal at the main mix bus.

Some variation of "submix group bus" describes a bus to which you assign the output of some channels so you can control them as a group. You can adjust the volume of them as a group, apply effects to them as a group etc. Often this is just called a "bus" or it can be called a submix or group.
 
Massive Master has the best answer so far.

The difference between putting an effect on a bus instead of putting it directly on is because some effects (such as reverbs, delays, ect.) are meant to be processed on a copy of the signal so that you can control the amount of wet/dry you want in your mix. If you put a reverb on there directly, you're sending it 100% wet to the signal and you can't control the amount you send to the effect.
 
Sends can be used as busses as well. For example a simple stereo mixer with two aux sends can feed a 4 track recorder, giving you individual volume control: main left, main right, aux 1 and aux 2.

But sends also implies returns. You send out the track(s) to a reverb, or delay, or compressor etc. Then bring the effected signal back to the return jack and blend the levels between dry and effected signal to taste.
 
Dang, this is one of those things that would be much easier to demonstrate than to try and explain in text only. I agree that Massive Master gives a darn good start. Let's see if I can supplement what he said without confusing things!

(And I intend to seriously over-simplify here!)

Buses tend to be a way of grouping two or more individual channels together just to make mixing easier. Typically, it would be several related channels (Massive's example of drums is a good one but it might also be backing vocals, or maybe the whole brass section or whatever) with the Bus then fed to the main mix. This lets you change the level of the drums or backing vocals or brass or whatever in the mix with a single fader while maintaining your carefully set balance within the group. Without a bus you might have to move six or eight faders at the same time and keep the level relationship the same as you do it. Obviously, there are other potential uses (for example, in live work if I don't have a speaker management system I've sent anything with lots of bass to the subs and other things to the full range speakers (using bus outputs rather than feeding it the main outs) but the first example is by far the most common.

Aux Sends are a way of pulling the signal off one or more individual channels to do something separate from the main mix. They can do lots of things--feed a channel to an effects unit and be able to mix the reverb (or whatever) in and out, create monitor mixes, either for headphones in the studio or wedges when live and so on. Another use I've had in live situations was to create separate mixes for recording and things like backstage speaker feeds.

It's worth saying that there are two sub classes of Aux send: Pre Fader and Post Fader. Some mixers let you switch Auxes between the two types while other just give you a few of each. Pre fade auxes are useful for monitoring or recording feeds because the mix on the aux is pulled off before the fader and doesn't change when you adjust the main mix. Post fade auxes are good for things like reverb effects because the effect can fade in and out as you raise and lower the channel(s).

As you can see, there can be overlap between buses and auxes--sometimes you have to take a decision which suits you best. Just to confuse you more, many mixers allow you to have aux sends on bus faders--so you can group all those backing vocalists on a bus then add the reverb to all of them at once on the bus instead of controlling a bunch of aux sends separately.

An insert is something on an individual channel that lets you interrupt the signal path, send it to some kind of processing like an effects unit or a compressor then bring it back into that channel permanently. Usually inserts are taken out immediately after the channel pre amp but some boards let you go pre or post EQ. In either case, the effect is already added before the signal gets to the fader and the only control you have is on the effects unit itself, not the mixer.

I won't try to better Massive's sidechain explanation!
 
Just to be clear about something that was mentioned earlier in the thread. The reason to use sends instead of inserts on something like a reverb has nothing to do with not being able to control the wet/dry mix. You can still control the wet/dry mix even if you inserted an effect directly into a channel. There are a million other reasons to use a send, as has been mentioned by others, but control over the wet/dry mix isn't one of them.
 
Yes and no, RAMI. Depending on the effects box you use, it's usually possible to control the wet/dry mix after a fashion but it can be far from convenient, especially in live situations. Don't forget that, with a big live board, your effects unit may be in a rack ten feet away from the fader for channel 1 or whatever. For subtle adjustments on the fly, there's nothing like having one fader for "full dry" and another nearby for "full wet" and mixing between the two just like you would with any two sources.

Even with DAWs in the studio, there can be great differences in the ability to automate the wet/dry control in a mix.

It's all down to personal preference--but I tend to use inserts for "set and forget" effects and Auxes for those where I want more (and easier) control.

An, of course, inserts restrict you to one channel per effects channel. Using auxes lets you put the same effect on as many channels as you need.
 
Bobbsy said:
Yes and no, RAMI. Depending on the effects box you use, it's usually possible to control the wet/dry mix after a fashion but it can be far from convenient, especially in live situations. Don't forget that, with a big live board, your effects unit may be in a rack ten feet away from the fader for channel 1 or whatever. For subtle adjustments on the fly, there's nothing like having one fader for "full dry" and another nearby for "full wet" and mixing between the two just like you would with any two sources.

Even with DAWs in the studio, there can be great differences in the ability to automate the wet/dry control in a mix.

It's all down to personal preference--but I tend to use inserts for "set and forget" effects and Auxes for those where I want more (and easier) control.

An, of course, inserts restrict you to one channel per effects channel. Using auxes lets you put the same effect on as many channels as you need.
Click to expand...
I completely agree with all of that, Bobbsy. My point was that controlling the wet/dry feature is pretty standrard on most (all?) reverbs. So, while I wasn't advocating the use of time-based effects like reverb and delay as inserts, controlling the wet/dry balance isn't the strongest reason for it, since you CAN control the wet/dry if you really had to.
 
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Hey everybody. Thank you all for the time you have spnt helping me out explaining this in depth like that, and this is why I LOVE HR. theres so much highly valuable knowledge and content in this post, that i feel I just took a class on busses/sends. im going to be doing some mixing tonight and im sure ill be back:thumbs up: Thanks again, Shawn
 
Just wanted to thank you all here for helping to clear this up for my application and needs. A real solid set of explanations upon first search!
 
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