Can anyone tell me the main cause you experience as a live gigging sound engineer, regarding feedback? Just interested...It can be monitors too loud, gains of FOH too high etc. I want to eliminate each problem that I experience. Thanx! 8)

Biggest culprit is mics pointing at the monitors (directly or indirectly). If the area behind you is reflective, the mid to high freqs bounce off and reflect back into the mic pointing at you. This can also cause comb filtering, or the "swallowed" effect. Get some absorption behind you or adjust mic-placement.

Another common issue when using multiple mics is phasing and comb filtering. While this doesn't directly create feedback in most cases (though it can), the frequency cancellations will cause you to push the overall level up, causing other frequencies to feedback. Fixes: adjust mic placement, flip phase on additional mics, or mute un-needed mics. For example, when our pastor stands up on the stage, I mute the choir mics, because the signal from his lavalier, summed with the delayed signal from the choir mics (they hang from the ceiling) create really bad comb filtering and resonances.

Hey! Thank you so much for the advice! I will definately keep it in mind when setting up again and flying the desk. Although I am not a professional sound engineer it always helps to know as much as possible and give advice to those who are open to advice. I own a PSE 3k rig and I usually hire in a pro, but sometimes we just can't get the feed fixed. Does the quality of ones monitors also contribute to the feed problem? I only use two monitors, but they are not that good, but they do the job. Once again, thank you so much for your advice!

I'm not a sound tech, but I'm a regularly gigging bassist/guitarist and have worked with a ton of different kind of sound techs. By kind I mean the quality of their work ranging from great, to useless.

The most annoying problem I've run into is that the sound tech has hearing damage and can't hear that the sound is total garbage. This one gig, everything sounded fine on stage but there was horrendous feedback coming through the PA speakers. Unfortunately neither I or my band heard it and the entire gig ended up sounding like a massive mush of ludicrously loud feedback.

So firstly, PROTECT YOUR EARS! PLEASE! And unless you're doing a stadium gig, the band doesn't need to be ear-bleeding loud.

Also, when mixing the bass, don't crank the bass knob on the EQ board all the way up. Unless the bassist is plugging straight into a direct box, it won't need to have frequencies boosted so dramatically. That will just muddy the sound a whole lot. I've gotten up there and played my face off too many times only to have people later in the audience tell me that the PA speakers were just flubbing out on every low note. So, if the bass sounds like a fart, turn it down lol.

Make sure to do more than a 10 second soundcheck. Also, what settings work for band A, might not work with band B. Use your ears, not some setting you memorized from a book. That seems like a limited view on my part, and it is because I don't know what kind of studying these guys go through. But I've worked with too many "professionals" only to be disappointed or frustrated by the process and results.

Guitar player: "Every note sounds horribly loud and unclear, please turn me down in the moniters"
Sound guy: *turns all the way off*
Guitar Player: "Uh, I need a little more"
Sound guy: *cranks all the way up*
*repeat process a couple of times*
Guitar player: "Just put it somewhere in the middle."
Sound guy: "Can't do that, sorry."


And thats not even an exaggeration.

If theres too much feedback, start by turning the gain down on everything until it goes away. Then slowly turn each separate gain or level knob up until one starts to feedback. That way you'll isolate which one it is and can make adjustments accordingly.

I've never worked live sound before though, I'm just saying some of the problems I've seen. Almost all of which in my opinion could be easily fixed with common sense.

here is a primer I wrote sometime back regarding setting up and running live sound.. should be useful to you.
Kent

www.imusicscene.com/forum/viewtopic.php?f=30&t=11851

Kent...what an incredibly useful reply. thanks so much for posting that sound setup article. I'm going to learn a lot from it.

Terry