How to setup a mixer at FOH

July 9, 2008 11:41 AM

How do you setup an audio mixer when mixing from FOH (front of house)?

I have dabbled in many areas of sound production for several years, mostly doing MC/DJ gigs for parties, bars, and weddings. Recently, we've "run sound" for a couple of bands. I'd like to do more of this, and I've realized that to do it right, we need to setup the mixer at the FOH (front of house) to be able to hear the levels and EQ settings for each line, and do all the mixing. I'm sure you've seen setups like this at concerts and such.

My question is, how do you set this up with cables? For example, a typical band that we run sound for will have rhythm guitar, lead vocal, lead guitar, backup vocal, bass guitar, three drum mics, and maybe a keyboard. Do you have to run all the instrument cables to the FOH position? This would mean a 100 ft. XLR cables for each line. In the case of this band, that would be nine XLR cables to run to the mixer, and then a pair of Main Outs back to the amplifiers.

Is this how it's done or is there an easier way?

posted by chitlin to media & arts (7 answers total)

You need to buy a snake that has the capacity to do what you want. It just consolidates all the cables into one big thick cable. Random Google for an example product (not recommending this or anything, just showing you what it looks like).

Sometimes the place is already wired with XLR runs as necessary so you just plug into jacks on the stage.
posted by cmm at 11:47 AM on July 9, 2008

A snake is a must, as is stage monitoring. A band that can't hear themselves over the room noise will sound like crap.
posted by chrisfromthelc at 1:09 PM on July 9, 2008

A snake is a must, you will need a good eq to ring out the microphones. When I ran sound I would run the system mono. I'd look into a mixer with subchannels so you can run a monitor mix to the band...

How complex do you want to get?
posted by Ponderance at 2:03 PM on July 9, 2008

Yes, a snake.

But it's also true that at many venues there's no true FOH location, so whether you're running a snake or not a lot of your time will be spent wandering the floor. This is normal, and is true even for huge venues with ideal, center-of-the-audience mix platform.

All good sound engineers wander the floor to hear how the sound changes. Big shows align the arrays to throw similar sound throughout the venue. This used to be done solely by ear, but now there's software to do it.

Check the front of the dance floor / mosh pit. Check the back of the room. Stand in front of the speakers. Stand in the front row between the speaker arrays. You'd be surprised how much the sound changes, and how much improvement you can make without really hurting the sound.

Sometimes it's easiest to keep the mixing board out of the way with good sight lines to the band, and mix FOH by carrying a radio or using hand signals with your 2nd engineer at the board.
posted by lothar at 4:13 PM on July 9, 2008

You'll want to get a XLR splitter for any shows that have a monitors mix position. (Random google, not a recommendation)

This will allow you to send the same sources to both the FOH and monitors desks.

When shows get even bigger, and have mix-for-TV or Video trucks, you might even see three or four-way splitters on the stage XLR.

But, that's way above what you really care about :)

Yes, a snake is the answer. A common size for small-to-medium stage mixing is an 24x8 - 24 channels, 8 returns. This will allow you to send some things back to the stage, like doing rudimentary monitors mixing from FOH, as well as sending back your main mix.

For EQ, you'll want two different kinds - parametric for group inserts on the board, and graphic for the main mix. You should have about 4 channels of parametric EQ handy. Many FOH boards have parametric EQ built into each channel. This makes some things easy, but some things harder; if you have outboard EQ patched through, you can route a submix or a group of mics that all need the same EQ to one outboard EQ.

To "ring-out" a room quickly, you can get a pink-noise source, a spectrum analyzer and a calibrated mic. You play the pink-noise through an input. It comes out the speakers and goes into the calibrated mic which is plugged into the spectrum analyzer. The spectrum analyzer shows you visually where the hot spots are, so you can turn them down on the graphic EQ on your main mix.

Then, you're just using the parametric EQs to make the mics sound good for the application, not to remove feedback.

Another thing you will probably want for the protection of your equipment (most venues with house sound will have this in place between you and their equipment) is a brick-wall limiter. And, if you are having problems with getting your vocals loud enough to compete with instruments, you might want to have a couple of outboard compressors.

Oh, and don't forget to get a suck knob.
posted by tomierna at 6:05 PM on July 9, 2008

Snake. I'd use at least a 12ch for that setup (9 sends, main and monitor returns, one spare)

They're big and easy to trip over, so bring some cheap rug scraps so you can lay it over it at traffic crossings, and get some gaff to tape it down with. Don't lay it down in parallel with power over 20a, or you'll risking an induced AC hum.

Have your stage hand make up a connect list at soundcheck, (ch 1: Lead vocal, Ch2: Lead DI box, etc...), they keep a copy, you keep a copy. Or, if you always use the same snake, put tape on it and label the jacks. The last thing you want is for anybody to be confused about anything.

FOH warning: Never, ever, leave the rig set up in such a way that an audience member can leave a drink sitting on something expensive, or they will, and Bad Things will happen.
posted by Orb2069 at 6:17 PM on July 9, 2008

The suck knob is a must. All sound engineers keep that on hand.

I once ran sound a college that shall remain unnamed, and they had a nice stage/sound setup in their student space and had a great budget for events and music. The had lots of amateur night rap/ hip hop shows, and due to some problems I had to institute the "Anyone talks shit about me our my helpers looses mic privileges" rule. So while I didn't have a suck button, I'd have 3 or 4 guys onstage and someone would start saying things about the engineer and how we didn't make them loud enough etc. and, click goes the mute button. It was pretty funny. Eventually the event organizers (they did a lot of these shows) got the message and everyone was nice as can be after that.
posted by Ponderance at 7:28 AM on July 10, 2008