Using PA Effects For Live ShowsJune 20, 2008 1:41 pm Live Sound
Those of us who record and mix music in our home studios have become quite familiar with the use of effects like reverb and delay, usually applied during mixing, to enhance the sound of the basic recorded tracks and to help the pieces of the mix “fit together” properly. But what if the band is playing live, using a PA system, instead of laying down tracks in the studio? Do we really need to bring along our whole arsenal of studio effects?
A key difference between the live situation and the studio situation is that a PA system, where the live effects would be added, is generally used mostly or entirely for vocals (see my article Using Onstage Amps vs. Playing Through the PA for some thoughts about using the PA for instruments as well as vocals), whereas in the studio, every instrument and vocal, even the drums, can have effects added.
Another reason to focus primarily on vocal effects in a live situation is that the instruments typically have effects added to them before they get to the PA. I am thinking of the “stomp boxes” or multi-effect units that guitarists often insert between the guitar and the amp, and the built-in effects that most keyboards make available. All this means that when we talk about PA effects, we are basically talking about vocal effects.
Mixing It Up
Most all-in-one PA units, also known as powered mixers, have a basic set of effects built in. When I first started running sound for Rusty Strings, we used a Kustom 8420 PA system, which has two separate effects circuits that you can apply to any channel as desired via “Effects 1″ and “Effects 2″ knobs in each channel strip. Most of the available effects are reverbs of various lengths and delays of various lengths. (This makes sense, since these kinds of effects will be more useful on most vocals than chorus, or flange, or fuzz.)
If you are using a separate mixer and power amp, you will have to acquire an outboard effects box, since mixers typically provide connections for effects units, not the effects themselves. This is the kind of setup we are using now, as you can see in these photos:
|Rusty Strings PA Setup - Front|
|Rusty Strings PA Setup - Back|
A dual effects unit and a power amp, which is very heavy, are mounted in a portable rackpanel. One channel of the power amp is used for the main speakers, the other for the monitors. The monitor signal is taken from the mixer’s “Aux 1″ effects send, while the “Aux 3″ and “Aux 4″ effects sends go to the two channels of the effects unit. A common effects return is brought in on an unused mixer input.
(See my article A Basic Live Sound Setup Diagram for more info on the Rusty Strings live setup.)
FX R Us
As for the vocal effects themselves, the two we use are a medium-length reverb and an adjustable delay. Of the two, I consider the delay to be much more important. Reverb is an effect you use in the studio to make it sound like a dry-recorded instrument is playing in an actual live location. The thing is, when you’re playing live, you are in an actual live location! Unless you are outdoors, you will get plenty of natural reverb from the room or venue you are playing in. Adding more could muddy up the vocals and obscure the lyrics, something you definitely don’t want.
Having said this, one of the singers in Rusty Strings has asked me to always have at least a little reverb on his vocal and to throw in the delay when I think it’s needed. Meanwhile, another of the singers told me not to ever put any effect on his vocals, not even a slapback echo in the rock-n-roll numbers. Naturally, what the band members want gets done just as they say. I’m only the sound man!
If possible, be sure to get a delay unit whose timing can be sent by tapping a front-panel button at the desired rate. In the studio, there’s plenty of time to fool around with making the delay 80 milliseconds, no, try 100, now try 90, and so on. At a show, you need to be able to set that delay fast. Assuming you like the sound of having the delay time synchronized with the song’s beat (like I do), the ability to just tap a button at a quarter- or eighth-note spacing to set the delay time is just the thing.
Although there are a lot of effects units out there, we have been using a Lexicon MX200, which has worked out great so far. In fact, we will be using it this very evening!Tags: effects, live mixing, music technology, PA systems -->