SC48 Configuration

[Limelight]

As I anxiously await the arrival of our new toy, I find myself spending way too much time pre-programming our console file, HA! Couple of questions came up last night I wanted to throw out at everyone, here we go:

Using VCAs and Groups - Should this be done? I want to group certain instruments for plugin insert purposes. So do I assign those instruments to the LRC bus as well or drive them from the group bus? Also, is it common to leave the group faders at -0- and then use VCAs to control grouped instrument level adjustments? If I have all my kick channels assigned to Group 1 and VCA 1, which one do I adjust, the VCA or Group fader? Am I making sense?

Inserting a channel - Say I wanted to insert a blank strip to add another guitar/bass channel, when I "insert a blank strip" nothing is there. How can I get an input strip inserted and then also not affect my input patching? Is this possible, as sometimes I have a bass player who says, "hey man, I'd like to run 2 bass lines tonight," and I don't want to have to throw him on the end of the chain.

Thanks guys!!!

Chris

[Brent Lind]

Ok, using groups and VCAs. Not really any different than on an analog console. I'm a big fan of using both, but in different ways. Remember that audio doesn't pass through a VCA and processing cannot be applied, its strictly a remote control for fader levels.

A common workflow, that I believe in very much is to route everything through various groups. You can apply whatever processing you like to summed groups. When it comes to setting a level, it doesn't necessarily need to be at zero db. Think of this as your "gross" mixing levels. Group instruments by section and set levels that feel right. I often end up with drum and guitar groups at -10db and vocals at zero. Its all relative and you can do it however you want, but the purpose is to keep your channels in the optimum resolution range.

Resolution is extremely important on any desk, analog or digital. It refers to the fact that faders are non-linear, meaning that from 0db t +5db is maybe a centimeter of travel, whereas in the lower resolution section of the fader, say from -10db to 30db is also a centimeter. If you operate input faders in the lower end of the resolution scale, it becomes very difficult to make subtle mix adjustments, because moving a fader 2mm drops the level 10db or more! This is true of VCA's as well, as they are simply controlling your input fader.

Groups will allow you to operate at ideal input gains AND in high resolution on both channel faders and VCAs, and still have the levels you want, with very fine control. Ideally, if your groups are set correctly, you will mix the whole show with your input faders AND VCAs set close to zero, and all your "mixing" will happen up in the general range of -5db to +5db.

As for routing to the LCR bus as well as a group, I don't believe in it for the reasons outlined above. There are advantages to routing something to multiple groups, usually for achieving a blend of compressed and uncompressed. The classic example is having 2 stereo drum groups, only one of which is compressed and mixing a blend of the two. You could also do this by routing drums to a compressed group and uncompressed to the main bus, but again, this screws up your overall gain structure and potentially your resolution.

As for your other question, a blank strip is what it sounds like, an empty hole on the desk. If you want to double up your bass channel (i.e. 2 channel strips from the same input), what you need is an unused channel strip from the end of the desk, then use "move selected strip here" to put it where you want it. Patch it to the appropriate input and you're in business. Remember that those two channels are sharing a preamp, thus any changes to gain will affect both channels. Everything else is independent.

Hope this helps.

[Limelight]

Ok, sounds good. Resolution.......would love to read more on that as that is new to me. Any tips on good reading and or practical examples of its application? Thanks Brent!!

[Brent Lind]

Resolution isn't complicated, take a look at your faders and think it through.

Look at the number scale next to your faders. I don't have a desk handy, so my examples will be rough.

Down at the bottom, you'll see -40db, -30db, -20db etc. Look how close those lines are together. When you move the fader up like one centimeter, you are going from -40 to -20, which is 20db, a huge increase in level achieved with a very small fader move.

Now look up at the top of the fader. Its maybe a centimeter from 0db to +5db. So now if you move the fader a centimeter you are increasing level only 5db, instead of 20db. Make sense?

Its an issue of fine versus coarse control. You want to have fine control over your faders.

Lets say you have an overpowered PA and you do a linecheck and set all your gains nominally, but when you bring the faders up to zero, its way too damn loud. What do you do? Move all your faders down to -20db until it sounds reasonable?

Now your problem will be that with your faders down around -20db, you are in the low-resolution part of the fader, and you will find it hard to mix, because every time you make a tiny push or pull on the fader, instead of increasing a db or two, its jumping up by 10db!

Resolution is sort of a fancy word for it, but what we're talking about is the amount of fine control you have with the fader. If the fader was "linear" then there would be a strict scale like "each centimeter is equal to 5db" and then you could run the fader anywhere and have the same feel for adjusting levels. But its not. It's non-linear, meaning the higher up the fader goes, the finer the control.

I don't have any links to articles or anything. Hopefully that helped to clarify. Let me know if that is making sense.


Ok, one more example that might help explain why we call it resolution. Picture a crappy old laptop computer with a tiny screen. Now plug in a usb mouse to it. Move the mouse 1 on your desk one inch. Because the screen has tiny resolution, moving the mouse one inch on your desk will move the cursor halfway across the laptop screen. You made a small motion and it had a huge result. Low resolution. Try to draw something in Illustrator and you're going to get very frustrated, because you don't have that fine control.

Now, take that same mouse and plug it into a Mac Pro with a 30" HD screen. Move the mouse on the desk one inch. The cursor onscreen only moved a tiny amount across that massive screen. Why? Its high resolution. And you have fine control with that mouse. You can move that mouse cursor around and pinpoint where you want it to go.

Is that helpful?

[Limelight]

Absolutely!! So does this apply to my master fader as well? If I am nominal across the board for the most part, I know that with my system my master fader will be in the neighborhood of -10 to -15 to sound big but not too over the top. Should I make adjustments to my system processor to allow for the main fader to be close to nominal as well and not be too loud? I don't want to limit my headroom by doing this. Just so that I am keeping my input faders in the sweet spot so I can make fine adjustments. Very cool, thanks man!!

[Brent Lind]

That's a good question, and I'd love to hear an opinion from the experts. My feeling is that its fine to run your master fader down a bit. I don't know that resolution matters much in that case, since you aren't moving that fader around during a show.

Also, I think I'd rather leave the system processing intact, and run the master a little lower, because it leaves you some headroom, both in the desk and in the system. Headroom is a little like a gun, better to have and not need than need and not have.

Have fun with your new desk!

[Brent Lind]

Oh, but again, don't forget about groups. If you are doing gross mix adjustments with groups, then there is no reason you can't have both inputs and the master bus set at nominal. There is more than one way to skin a cat, but usually for me the groups are the only thing that gets dropped down. I like this because if you want to push a group up a little you've got the room. If they are all at unity and the master fader is down at -15, you can't really push group levels much before overloading the main bus.

I think at that point you're getting more into a matter of taste than strict rules of good gain structure. It depends on the desk as well. Some desks sound better with certain busses pushed harder.

If it was me, my workflow would be set input pre's nominally, leave your master at 0db, and bring groups up slowly to your taste.

[Scott Fahy]

Great advice regarding using the groups as an offset Brent. My approach is to use a combination of VCA's and groups to keep things balanced. I set input gain first, faders ,mains and VCA's at 0 and use stereo groups to get a rough balance and then adjust faders as needed. If I do it right my faders stay in the sweet spot 90% of the time, nothing get overdriven, this method also keeps whatever is going into the group compressors where I want them

Scott

[Kenmillerjr]

Very well put, Brent!

[Daniel Ellis]

What do you guys assign to your VCA's? The compressed group, or just the individual inputs? Or both at the same time?

Because if you just do the individual inputs, every time you push the VCA up you are basically lowering the threshold of the group compressor, causing more compression, right?? I think maybe I read about Dave Rat doing that or something.. Inputs on the VCA... So if you want more compression turn up the vca, but if you want more overall level with the same amount of compression you turn up the group.

what are everybody's thoughts on this?