Can someone explain to me about busses on mixing desks and what they do?

Thankyou =)
x

Depends on a few things.

It also depends on what mixer you have, and how you set it up.


"A bus is basically a path in which you can route one or more audio signals to a particular destination. Destinations can include groups, auxiliary sends, stereo mix, foldback or monitor. Commonly busses are used to route channel signals to a master group fader, a multitrack recorder, or the main stereo master fader (or all).

In live sound applications it is favourable to have a number of busses available to use. This is due to the fact that as audio channels can be bussed together and controlled by one group fader, it frees up the hands of the engineer and gives him/her less faders to have to control on the fly. It should be noted that although the master group fader does have control over the level of the summed audio in the group, the individual levels will remain with the offset set on the channel fader."



Quote from Dolphin Music.

John Denim.

Oh I see, So basically in live sound its like a sub group?

Signals can be sent to a sub group, yes.

It's anything you can send sound through. An Aux is a bus so to speak as is a Sub group.

Josh

Ahh I understand now, so an effect bus is basically an aux send?
Simple... Cheers guys

Mixers with individual input circuit boards used to have their outputs (left, right, pre/post fade auxes, subgroups and even pfl etc.) connected by stiff copper wire to the output section (later done with ribbon cables). This allowed all channel signals to be connected to their respective master section. It was common to refer to the "left and right bus" and so on. The drawback to this arrangement was that although you could route a channel's signal (via switches, aux sends or pan pot) to a given bus, you couldn't usually alter the nature of that bus..... it was always connected to the same destination. Some analogue desks did have more flexible arrangements, but generally the "number of busses" referred to the number of outputs to groups (and L&R). This was important for recording.

With digital desks the routing between inputs and outputs is much more flexible, and busses may refer to the total number of configurable paths between inputs and outputs.

Simon

Channels go up and down, a bus tends to go left to right!

I know there are exceptions, but in its' simplest form that seems to be the crux of the matter (alright, until they get to the masters section when they turn towards the back of the mixer again!)

Firstly the term is an abbreviation of busbars - which as already stated - were traditionally thick copper wires used to common all the signals from the input channels to the output section (and often carry power supplies also).

So a bus is a common link, with mixing circuitry on the end, used to combine (or mix) signals from the input channels. This will include, L+R, Aux signals, Groups and PFL and possibly others.

If you look at the routing diagram of almost any mixer, you will see a collection of (usually) vertical lines connecting everything together. These are the busses.

Mix Wiz block diagram

If you look at the block diagram of the 16 channel Allen & Heath Mix Wizard above - you will see the busses clearly.