Feedback in monitors

Posted: Tue Sep 09, 2008 2:16 pm

will someone share the formula for one to go by to set up monitors without feedback because it amaze me to see on tv that a perfomer is standing right close to the monitors without feedback so this is my situation. now we have 6 monitor made by kustoms and im using qsc 1450 amp with alesis firewire multimix 16 track and a behringer ultragraph pro eq will somebody assist my situation?

Posted: Tue Sep 09, 2008 6:24 pm

I don't know if I would call it a formula, but...

Use a cardioid or supercardioid mic. Point it away from the monitor. Turn the monitor volume down until the feedback goes away. Perhaps cut a specific frequency if that is giving you trouble.

If there are any other magic tricks besides that, I'm interested in learning them, too. Wink

ps - perhaps this should be in Live Sound, not Vocal Booth?

Posted: Tue Sep 09, 2008 6:37 pm

Cardioid dynamic microphones are your friend as mwacoustic said.

Kustom's can handle wattage just like a Yamaha or other decent monitor, but because of the quality of the audio you need to crank the Kustom up more for it to be intelligible. There is more to audio than the numbers. Cheep speakers have poor transient response resulting in a mushy sound. They also have more harmonic distortion.

What happens is you bring up the volume to compensate for not being able to hear what is going on, and that results in feedback.

If the ultragraph has FBQ, then you can reduce feedback by bringing up the volume until the feed back starts. When it does, turn down the band on the EQ that lights up. This should work well if none of your microphones are hand held.

PS, what does your screen name mean?

Posted: Tue Sep 09, 2008 6:42 pm

Please give up some more information.

Are you recording live in a small room with 16 microphones and and 6 monitors?

Tell us EXACTLY what you are doing, and then maybe you will get some idea of what to do.

Everything that you can think of. Take some pictures, because you won't think of everything. The motto around here is "help us help you", but without very much information, you won't get very many responses that will help.

Posted: Tue Sep 09, 2008 9:34 pm

I found this in the vocal booth forum.

I wonder how it is going to end?

Posted: Wed Sep 10, 2008 3:02 pm

Moved to live sound -

OP - much more info is needed. Including the aforementioned requests.

I'm assuming (hopefully) that you're trying to monitor for live sound purposes and the fact that you posted in the vocal booth is because the vocals are the main reason for monitoring.

If I'm mistaken and you're trying to monitor vocals and (???) for recording purposes we have a whole different set of issues. If that is the case 6 monitors is an entirely incorrect approach.

Please elaborate.

Your friendly neighborhood Vocal Booth Mod

Phil

Posted: Wed Sep 10, 2008 5:24 pm

First off, you have to understand what causes feedback in the first place...sound from the speakers (as well as reflecting off of the walls, etc)
re-entering the mics. So you need to be sure that the monitors are not firing sound into the "hot spot" of the mics. You need to ensure that the monitors are firing at the "null spot" of the mics (this is the mics' least-sensitive area). Knowing your mics, their polar patterns and frequency response curves, as well as the dispersion pattern and response of the monitors will be the key to getting things loud and feedback-free. All of the EQ gadgetry in the worl is useless if you don't get that down first. So, like the others have said, we need to know what mics, etc. you are using...

Posted: Sat Sep 13, 2008 9:44 am

Here is the deal. The original poster is using Kustom wedges and Behringer.

Anything that a pro would do might still not be good enough.

Original Poster. It is only possible to get 130 decibels on stage for these guys with mics in close proximity to wedges and FOH mains used as side fills, because the speakers systems are more than simple drivers in a slanted box. There is allot of engineering to make a wedge work without loads of processing.

The mics are very important. The mic technique is important as well.

There is much more processing (and more precise and thorough) than what is afforded to you in the Behringer.

If you read the Yamaha Sound Reinforcement Handbook, that will be a good place to start. Then experiment. You might also go volunteer for a good rental company to get some exposure to pro gear and methods. Then you will be armed with the knowledge to make your stuff work better for you in your world.

Posted: Sun Sep 21, 2008 8:43 am

I thank you all for your help in even if i am in the vocal forum you all still assisted thanks once again however one did want to know about my screen name, well i took that because what i do in life is for god and im duty bound to tell the truth so that is why that is there so back to the subject i uses sure mics and yes its for peforming live however what about the statement of one standing on the monitors without getting feedback and do i have the right tools to be sucessful in my mission if not then where can i go to brush on my engineering skills to tackle this job i need help thank you

Posted: Sun Sep 21, 2008 10:06 am

. . . . . .
, , , , , ,

I had a few extra here, feel free to use them! Wink

To get more specific help, we will need more details about what "this job" you have is. You did mention the monitor gear you are using, but we don't know anything about the band, the style of music, the venue, etc.

Otherwise, it's back to what has already been stated - reposition the monitors/mics, turn down the volume, use eq and/or better gear to provide the clarity you need at lower volume.

Posted: Sun Sep 21, 2008 10:49 am

I don't think godtruth is interested in helping his own situation.

If there were any godtruth in that, then statements like;

mwacoustic "Use a cardioid or supercardioid mic."
GeckoMusic "Cardioid dynamic microphones are your friend"
moonbaby "Knowing your mics, their polar patterns and frequency response..."
sheet "The mics are very important. The mic technique is important as well. "

would not be taking up much needed space!

Instead godtruth brings more mix to the mess with this unqualified comment "...statement of one standing on the monitors without getting feedback".

If I had this problem with feedback, based on what I have read here, I think I could have gotten a handle on it already Smile

And if I didn't have a handle on it, at the very least I would tell the thread participants what kind/type of microphones I was using, even if it resulted in embarrassment Smile

But, I am a carpenter by trade, so your mileage may vary.

Posted: Sun Sep 21, 2008 1:10 pm

First, let's give Godtruth a little break here, because I suspect from his sentence construction, and lack of punctuation, that English is not his first language.

Secondly, it should be obvious to everyone that he is not a professional sound engineer, and is trying to learn. Also, judging by the number of posts, he is new to these forums and may not yet understand the need to be very specific and give forth as much information as possible to get satisfactory answers. If he's paying attention, he should now be adequately informed.

Many, many years ago, when I used to play out live, our sound engineers would "ring out" the monitor system by bringing up the volume just to the edge of feeding back, then back it off a little, and bring up each slider of a 31 band graphic eq until it started to feed back (ring). then they would back the slider off by a couple of db until the ringing stopped. By working their way thru the frequencies this way, they could get a pretty good eq of the monitor system adjusted for the acoustic properties of the venue.

Of course, there is almost nothing that can be done if a performer points a mic directly at the speakers of inexpensive monitoring systems.

Posted: Sun Sep 21, 2008 1:24 pm

Maybe godtruth should ask the question in his native tongue?

Posted: Mon Sep 22, 2008 6:20 am

I must say that you all gave me my first lesson on how to respond properly,and to take heed to what has already been shared. Must not forget SPACE you did hit me hard,however i understand and AWEDONE, good looking out for one that is learning how to respond to get the right answer.It also shows on both end of the spectrum that you all are willing to help anyone. And for that it shows this is a wonderful place to get answers.So will take what is shared and move on that,however i will be back because i am a new person in recording and live session, so bear with me until next time...

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