The FX rack

[Guest steve113]

sorry another question!

 

before I start let me say I am a rock 'n' roll lampie, not a sound engineer. you guys do a great job, but its not for me.

 

for Church I get roped onto looking after the technical stuff. theres a young guy who looks after the sound, and I supervise and do lights. we have a rather nice PA [DB I beleive] and we get asked to do a lot of amaeur dramatic productions with it. we have a GL2400 which we use, but we are getting a little fed up with re-patching our rack. for a beer or two I have offered to sort the purchase and solder a loom system.

 

where are both stuck is to how to wire the connectors at the desk end. having compressors on stereo jacks desk and for inserts is the obvious choice. we have effects units [2 of] and we are stuck to how one would wire these up. the units are new and I beleive that you can insert these or have reverb as inputs? but what is the best connector to use? the only XLRs on the back of the desk are for the 4 groups, and 3 outputs. everything else is jack. the AUXs are on jack and I beleive with no return. how does everyone else run effect units with their desks?

 

we also have one of these> http://www.terralec.co.uk/prod.asp?I=18727...ECTRUM_ANALYSER what I asusme is you have two mono jacks one as an input to the unit that you plug into any channel with bad feedback and another for the pink noise input, is this the case?

 

many thanks, I am sorry I know so little about this!

[Bobbsy]

I don't know if your budget or resources will stretch to this, but the obvious way to handle situations where some flexibility is needed it to bring all your sources and destinations back to a few strips of audio patchfield. A permanent connection is made to each of the inputs and outputs of your mixer, then take these back to the patchfield. Regular connections can be normalled, but you have the ability to make temporary or less used connections via a standard patch cord (usually quarter inch "A" or "B" gauge).

 

Unfortunately, patch fields aren't inexpensive and it will mean a lot of wiring for you...from your description of the use, it might be worth it though.

 

Bob

[Guest steve113]

thanks.

 

the plan is a harting on the back of the rack and a loom with thr desk. I feel a patch bay would be unnecessary as we can simply swap XLRs or Jacks on the back of the desk.

[colebrooke]

Hi, you have the right approach with your compressors. With your other effects like reverb you'd want to have on balanced jacks, and probably leave them patched into aux 5 or 6 on the desk. Likewise, use jacks on the effects returns, which can either go to the FX returns on the desk (jacks I think on the GL2400), or a regular channel line input if you have enough spare. Yes you can use reverb units as inserts, but it's not so versatile, and is less commonly done.

 

There are a couple of ways to wire your analyzer. I don't think you can run your main outs via this unit. The output is only for pink noise, and the inputs are unbalanced jacks anyway. I think it's designed to be used more with the measurement mic, and the pink noise outputs into your system, for tuning / EQ. If you like flashing lights, you could split a L, R or mono out from the desk and send it to the analyzer... it would look pretty but I don't know how much practical use it would be - at least with this particular model!

 

Hope that helps!

Justin

[Shaggy]

Compressors and gates are (almost) always run as inserts on a channel. You'll probably want a loom with multicore cable going from a stereo jack at the desk end to two XLR or jack connectors at the compressor end for each compressor.

 

For your effects units run them out of an aux on the desk to the input of the fx unit, then out of the fx unit back into the desk on a channel or two. This allows you to use the same reverb on multiple sources. Have the fx unit set up so it only sends the reverb and not the direct signal, and control the amount of reverb with the channel.

 

For the spectrum analyser I would want to give it the signal from my cue bus personally, giving you some help finding feedback frequencies etc. I'm not too familiar with the gl2400 but some allen & heath desks that I've used have an output for headphones and one for a cue wedge, so plug the cue wedge (local monitor?) output into the input of the spectrum analyser.

 

If this is a mobile setup you might want to consider having it on a multi-pin so that you can leave the desk patched the same and just disconnect the rack. EDAC connectors are quite cheap and will stand up to this use. This would be a lot of extra hassle however.

[bigglesuk]

All of your connections for compressors/FX should be on balanced/stereo TRS jacks.

 

For the FX take an aux output from the desk into the FX unit. The returns from the FX can either be patched into the stereo returns, or into a standard channel strip.

 

Use balanced audio multi-core cable for all sends/returns. Inserts should be wired balanced out of the outboard units and then sum the negative and earth together at the desk end. If you are going to compress vocals, make sure the signal is split so you don't compress the monitor sends.

[Guest steve113]

Thanks very much! very very useful!

[Rob_Beech]

I take it by your idea of multipin connector this isn't an install then. something that is setup each week.

 

Do things vary that much?

 

if you use the multipins on the inputs and on the inserts etc for compressors and gates and your reverb sends and returns then you should pretty much be setup. a few changes to insert positions here and there if needed. I can't see you needing any more. You seem to have the right idea. I'll agree with the others that the reverbs etc need to go out of an aux and back in through a channel. So a balanced connector each way.