I just don't get bus?

Hi all,

I'm slowly getting my head around Logic. I've been DJing for ages, but producing for - well, a year or so.

No matter how often I check the ref manual, I just can't get my head around bus and how it affects a track and how to get it right whilst keeping all my levels in place.

I know this is bread and butter production stuff - by my breads gone moldy.....

Please help

my breads gone moldy.....

I know the feeling.

Can you be a little more specific about where you're lacking in understanding? Do you need to know what a bus is? Or how best to use them?

Think of a bus as a wire. Really, just a wire. Here's an example:

audio track

(send 1)------------->aux (hosting reverb)

The dashed line above is the bus. If you you have send 1 activated on the channel, Logic will tap the signal from the channel and send it along the bus 1 "wire" to the aux. The amount of signal that gets to the reverb (via the bus) is determined by the level of the send control.

The busses are always there. It's just a matter of whether you use them or not. Activating send 1 on a channel and turning up the send knob will put signal on bus 1. Activate send 2 and you're sending signal along bus 2...

If you were to change the output of a track from Out 1/2 to a Bus, and then set up another track so that its input was that Bus, you can record a signal directly from the first track to the second track. In this case, the bus demonstrates itself to be a straight wire, carrying the signal from the first track's output directly to the second track's input. No send needed in this case.

Audio 1 (output = a bus)------->Audio 2 (input = that bus)

In summary, the bus is a wire; you can think of it as having two basic purposes in Logic:

a) to "tap" signal from a channel and send it somewhere else (typically a reverb or other effect hosted on an aux)

b) to make a direct connection between a channel's output and another channel's input

There are of course other uses for busses, but for sake of brevity (and not to get too deep into it) I think that should get you started.

HTH,

Ski

Thats helpful, thanks. I kinda get the concept, but don't quite see what the benefits are? I've tried messing about the sending outputs to other channels with efx on via bus , but the end result seems the same as when the effect is on the host track in the first place.

Am I missing something ?

If you put an effect on a channel or instrument, that effect can only be used for that channel or instrument. But It's common for several instruments to be sent to the same reverb. So if you were to host the reverb on an aux, you can then send signal from many different channels to that aux using sends.

Here, you'd add the same numbered send from each of those channels (say, send 1). How much you turn up send 1's control on each channel will determine how much of that signal feeds into bus 1, which in turn feeds the aux hosting the reverb. So if you had kick and snare, you could turn up the kick's send 1 just a little so that it didn't sound totally dry, but dial in a lot more on the snare to make it much more ambient.

Also, by default, a reverb's dry signal will be pegged at zero when you insert such an effect on an aux. This is because the dry signal's level is meant to come from the actual channels or instrument. The reverb then outputs only the wet signal, and its overall level is adjusted by the fader on the aux.

Of course you can always go into the reverb plug and dial in some dry signal to mix along with the wet signal, but it defeats the (beneficial) purpose of having the wet signal completely isolated on the aux.

When an effect (like a reverb) is inserted directly on a channel or instrument, the dry control will automatically be set to "unity" so that you can actually hear the dry signal. Signal chain is this:

channel's audio signal--->reverb, wet+dry balance--->channel's output

The reverb here is literally "inserted" in the signal path.

To summarize, hosting an effect (like reverb, delay, etc.) on an aux will let you "share" it for different tracks. Using a common send (i.e., send 1) for each channel or instrument feeds the same bus (wire) which then feeds the input of the aux hosting the effect.

Ski has pretty much covered it here but there's a few related things in this post:

http://www.logicprohelp.com/viewtopic.php?t=4159

This was written from a Logic 7 perspective hence the references to bus objects and Direction Mixer is no longer needed to pan mono signals down the bus line.

Just to add a further point to this discussion, it's useful to keep in mind that a bus is not "just" a virtual wire or path, but it is also a dedicated mix engine. Meaning that you can send multiple signals to a bus, they get mixed together, and that mix of signals is available for use in various ways, eg recording to a track, sent to a dedicated output, available to sidechains, and of course, available as input to aux's for returning that signal to the main mix, or other . . . and all of these simultaneously.

A bus's ability to take multiple signals from various places and deliver that mix to multiple locations is what makes it truly unique. A bus channel object, (optional, you must create these in the environment) provides a master level control of this signal and also provides a way to place effects on that signal, meaning that if you compress or expand, etc., with an inserted plug-in on that bus channelstrip, the effected signal will be what's available to anything that can accept a bus signal as its input. This kind of bus "master control" is extremely useful in mixing situations and one of the most powerful aspects of Logic's mixing engine.