Stage Monitors

[stuartsl]

Heya,

 

I'm doing a concert and I need to have a few monitors on stage. I will probably have these either running off the main speakers (just daisy chain off with the speakon) or run off a different amp coming out the desk, but what's to stop there being a huge amount of feedback from these as there going to be literally on top of the boundary and boom mics and very near vocals mics etc....

 

Help please?

 

Thank you

 

Stuart

[Bobbsy]

That's an apparently simple question but one that monitor engineers spend years trying to get an answer for.

 

Before going into a few suggestions on feedback control, the first thing to say is that it would be highly unusual to use the same mix in monitors as you send to the main speakers. Monitors are virtually always given their own feed, either from dedicated monitor desk or from a pre-fade auxilliary on the FOH desk. Doing it with an aux allows you to tailor the feed to what the people on stage actually need to hear. What is wanted will vary from gig to gig but, just as an example, you often don't need to include drums because these are pretty loud anyway. On the other hand, vocalists want to hear a lot of themselves because they tend to be drowned out by loud instruments. You will have to discuss with the musicians what they need to hear and balance the levels on the day.

 

As for feedback control, there are two main things to work on.

 

The first is the positioning of the monitor wedges. The mics on the stage will have a published pick up pattern showing where they are most sensitive and where they don't pick up much sound. The trick is to put the wedges where the mic pick up is least. Assuming you're not using omni directional mics (which would be unusual in a concert setting) most mics on stage will be either cardioid or hyper-cardioid. Cardioid mics have their least pickup directly behind them so put the wedges right behind the XLR connector. Hypercardioid mics are more directional at the "business end" but tend to have a small pickup lobe directly behind them. Their least sensitive spot tends to be at an angle behind and to the side of the mic.

 

The second thing to do is use EQ (equalisation) to cut out the most troublesome frequencies. You can do a lot of this before you even start by using a process called "ringing out". There have been several topics in the Blue Room about how to do this, but one you could try is HERE. Obviously, to do this you will need a decent equaliser, usually a 31 band graphic though there are some good arguments in favour of using a parametric. However, I suspect the latter are not good for beginners.

 

I suppose I should mention that some people use automatic "feed back killers" which are, in effect, automatic equalisers. I don't find these work particularly well but other swear by them.

 

I'm sure others will be along with some other suggestions soon but two final points. First, some extra reading might be useful on this--there are some good books on live mixing listed in the FAQ section. Second, feedback is always a problem even if you've done a lot of monitor work. One general bit of advice is don't be bullied into running the wedges too loud.

 

(And, for the benefit of others, I deliberately didn't mention options like in ear monitors since they would be too huge a jump for somebody who just wants to rig a couple of speakers!)

 

Bob

[nothingatall666]

you could just not have monitors :P

[Rob_Beech]

you could just not have monitors :P

 

 

Or you could use the methods Bob went out his way to suggest above and get good results.

[Andrew C]

you could just not have monitors

That must qualify, amongst a lot of contenders, as the most useless post on the Blue Room ever. Please THINK before posting.

[stuartsl]

That's an apparently simple question but one that monitor engineers spend years trying to get an answer for.

 

EDIT

(And, for the benefit of others, I deliberately didn't mention options like in ear monitors since they would be too huge a jump for somebody who just wants to rig a couple of speakers!)

 

Bob

 

Thank you, yeh I was thinking about having them run off the aux outs,

 

thanks for your suggestions I'm looking into them

 

Stuart

[Sirch Sound]

you could just not have monitors

That must qualify, amongst a lot of contenders, as the most useless post on the Blue Room ever. Please THINK before posting.

 

That made me laugh, but seriously there is no reason for not having monitors, if you follow the basic guidelines that bob set out you will end up with some decent results. It will also be a vry good learning curve for you.

 

If you find that you cannot quite get the results you need using your standed GEQ you could take a look at the behringer units with the FBQ on them. These basically identify the problem frequences by illuminating the faders with an LED. Its not perfect by any means but its still a hell of alot better than turning to a feedback destoryer in my opinion. Obviously I dont know the quality of the system your using so the behringer mght not be that helpful if your using a higher quality system.

 

Rich

[TallMike]

you could just not have monitors

That must qualify, amongst a lot of contenders, as the most useless post on the Blue Room ever. Please THINK before posting.

you could take a look at the behringer units with the FBQ on them.

 

or you could just not!

 

 

haha.

 

trick is, don't put your float / boom / ambient mics through your monitors.

 

silly idea, really.

 

put your vocalists, backing tracks, ipod, egg timer through them, but not 'ambient' mics. unless they're in a different room.

 

if your singers don't seem to be able to hear themselves, is it too loud on stage, or do they need a mic?

[BigYinUK]

Following on from Bobbsy's excellent post. We use a Behringer FBQ on the monitors. Wind the volume right up until you get feedback, see what frequency is causing the problem, drop the level on that slider a little , repeat a couple of times. Adjust the level back to something sensible and that's pretty much it.