I put on a gig once every month at a local club, using all my own equipment. I recently had a 3 mic front line with one person playing acoustic guitar. Not only did I have problems getting any decent level out of the vocal mics without them feeding back, I also got VERY LITTLE out of the mic I used for the acoustic guitar, in fact you could barely hear the guitar before it started to feed back.

I really need tips on using mics. I'm using an 800w PA system with a Behringer Eurodesk SX3242FX

I used 3 dynamic mics (one peavey, one Shure and one behringer) for the vocals and a small iSK CM-30 condenser mic for the guitar.

Where am I going wrong?!

Things to consider:

Where are your speakers in relation to your line of mics?

How directional are your mics? You haven't specified, but you need to know where the nulls are in the mics' responses so you can place speakers and foldback monitors effectively. Remember, if you have any hypercardioid mics, the null is not at the back, so you don't place them the same as 'ordinary' cardioids, especially in relation to foldback monitors. And if your condenser mic happens to have an omnidirectional pattern, never ever try to use it live, because that way is a steep plunge into the feedback pit. Condensers per se are not necessarily the culprit, but beig more sensitive, it's easy for them to become so.


Are you getting the mics close enough to the performers to minimise the gain required? You need to sing up and you need to 'eat the mic'. Being in the same room and roughly facing the mic IS NOT ENOUGH. NO WAY. EVER. Even if you have seen it like that on the telly.

Does the room have walls or furniture causing strong echoes back to the mics from the speakers?

Is the EQ as flat as it reasonably can be (to avoid frequency peaks that can trigger feedback)?

Do you have foldback speakers carelessly placed so they encourage feedback? And are they too loud?

Is the backline blasting directly into the mics (assuming you have a backline; not sure from your post)?

Are you muting (or at least turning down) any mics not currently in use (the more mics that are open the less gain you get before feedback)?

Do you really need that condenser mic on the guitar? A dynamic may well work better for live use or better still an integrated pickup. That may be beyond your control, and in that situation I'd use something like a Beyer M201 - dynamic, good sound, works well on instruments and as long as you remember it'a a hypercardioid, not a cardioid, very good feedback-wise.

I appreciate you may not have the mics that would be ideal for your situation, but take some time to check out their individual patterns and if necessary, tape a reminder on each mic as to where it picks up and where it doesn't (so much).

I suspect that your problem is caused by most of these factors contributing a bit to the overall picture. And if, as I say, your condenser mic (or any of the others) is an omni, there's the main problem right off. So, fewer mics, placed closer to the source, with singers putting more volume out and all of this happening well out of the way of the main speakers, with any foldback speakers placed in the null of each microphone will help a lot. You may also find that raising the mains and then pointing them down into the crowd will control some of the noise that otherwise flies around and reflects back to the stage. Then you may be able to turn them down a bit, giving you a bit more gain to play with.

If you can keep stage volume and the main volume down to sensible levels it's always easier to keep feedback at bay. No matter what people post on forums or tell you in music shops, you can't buck the laws of physics, and if you have too much gain in the system it'll feed back. Preventing it is a process of addressing every issue you can and eliminating or minimising it as a potential source of feedback.

If it's a familiar venue it's really easy not to notice problem areas that would stand out like a sore thumb if you went to somewhere new. Have a good look at what you've got to deal with and work out from scratch where the problems might be and how you'll overcome them.

That's a very comprehensive reply from tacitus which is worth studying.

The only thing that I would add is to avoid any compression anywhere in the system. You will often find that you have to turn up the volume to compensate for the compression and end up with less of a margin before feedback occurs.

I was at a gig last week where the sound engineer had a rack full of Behringer Composers and other gadgets which he kept on fiddling with all the time - often with headphones on so he couldn't actually hear what was going on. There was feedback everywhere - almost as if the sound engineer wanted us to think that he was part of the act!

James.

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JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.net

... very comprehensive post by tacitus covering all of the 'usual suspects' for feedback.

One other thing on the guitar miking... don't point the mic at the soundhole of the guitar. Not only will you probably need lots of EQ adjustment to get a decent sound, but it also significantly increases the chance of feedback from the guitar/mic combination. If the guitar has a pickup it might be time to think about a DI box...

Had to mic up 4 acoustic guitars at the weekend outside with the wind blowing straight at them - Pointless even trying

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PA Hire Surrey
Lighting Hire Surrey

Only solution (unless you could DI them, which obviously you couldn't) would be something like the AKG C411 - a very useful wee mic in emergency situations.

Bob

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www.bickerton.co.nz

You mean for me and the problem we had ?

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PA Hire Surrey
Lighting Hire Surrey