Microphone Feedback Issues

[welby]

Hi all,

I was wondering how different people deal with mic feedback issues.

The reason I ask is that I have a Dual Wireless Mic system which gives little or no feedback issues when a karaoke singer is out in front of the speakers which is great. Trouble is I don't want these to be ruined by the odd drunken singer (cough). I guess being wireless there is no direct loop to cause little or no feedback.

So I use a KAM KKA50 Karaoke Mixer (3 mic inputs) with cheap wired mics and feed this into my mixer desk. The trouble is this gives me feedback issues, and to overcome this I set each output as low as I can get them and use the mixer desk mic volume control, tweaking a bit as I go.

I have tried all settings, lowered the main speaker output, lowered the mic outputs. Short of asking the karaoke singer to stand 30ft away from the speaker I'm puzzled as what to do next.

I have considered buying a cheapy wireless mic for the karaoke and save the best one for sole DJ use.

Any suggestions greatfully received.

[A1DL]

Mark

The more open mics you have, the lower the gain before feedback, all things even 3 mics will give you 4-5dB GBF reduction over one.

I'm not familiar with the mixer you have described, however if it has a sweepable eq, you may be able to notch out the problem frequency and win a few dB.

Looking at the simplest things first though, try adjusting the placement of your mid tops to fix the source of the problem. Then look at getting some decent mics that are designed to work in high SPL environments, they won't cost you a fortune secondhand, will give you tremendous GBF headroom compared to a Craplins Diva-Pro Karaoke Mic or similar, and will sound much nicer in the mix.

Hope this helps

Tony

[CRAZY K]

Hi all,

I was wondering how different people deal with mic feedback issues.

The reason I ask is that I have a Dual Wireless Mic system which gives little or no feedback issues when a karaoke singer is out in front of the speakers which is great. Trouble is I don't want these to be ruined by the odd drunken singer (cough). I guess being wireless there is no direct loop to cause little or no feedback.

So I use a KAM KKA50 Karaoke Mixer (3 mic inputs) with cheap wired mics and feed this into my mixer desk. The trouble is this gives me feedback issues, and to overcome this I set each output as low as I can get them and use the mixer desk mic volume control, tweaking a bit as I go.

I have tried all settings, lowered the main speaker output, lowered the mic outputs. Short of asking the karaoke singer to stand 30ft away from the speaker I'm puzzled as what to do next.

I have considered buying a cheapy wireless mic for the karaoke and save the best one for sole DJ use.

Any suggestions greatfully received.

I would think its a question of how much you can spend to solve the problem.

I work in front of the speakers most of the night with a JTS radio Mike at loud volume ( or do I shout) and a Peavey Powered Mixer which has a feedback destroying feature.

Works for me--no problem---I did use a cheaper Numark Radio Mike before the JTS and that was pretty reasonable as well---its probably more to do with the amp/ mixer/ speakers than the mic in my opinion.

I dont do karaoke but imagine part of the problem is inexperienced singers probably never get close enough to the mike to get a decent sound---so you have to keep turning up the gain--followed by feedback problems.

CRAZY K

[welby]

Tony,

thanks for your comments. Thankfully I do not do karaoke a great deal of the time!


The more open mics you have, the lower the gain before feedback, all things even 3 mics will give you 4-5dB GBF reduction over one.

I take it there is more chance of someone walking in front of a speaker causing feedback


I'm not familiar with the mixer you have described, however if it has a sweepable eq, you may be able to notch out the problem frequency and win a few dB.

No Im afraid there is a no EQ.


Looking at the simplest things first though, try adjusting the placement of your mid tops to fix the source of the problem. Then look at getting some decent mics that are designed to work in high SPL environments, they won't cost you a fortune secondhand, will give you tremendous GBF headroom compared to a Craplins Diva-Pro Karaoke Mic or similar, and will sound much nicer in the mix.

I'm not sure about giving the punters good quality mics so they can get abused. I don't understand the term "high SPL".

After doing a lot of searching via web search engines. There seems to be some debate as to use EQ versus a Feedback Eliminator.

I have found one product that has MIC inputs with built in feedback elimination built in:

http://www.djanddiscostuff.com/prodpage.asp?prodid=2681

which seems on the face of it seems to do the job. Nothing flash or fancy, so long as the feedback eliminator works!

To be perfectly honest Tony, the amount of times I do karaoke just doesn't warrant spending shed loads of dosh on it.

Mark

[welby]

I dont do karaoke but imagine part of the problem is inexperienced singers probably never get close enough to the mike to get a decent sound---so you have to keep turning up the gain--followed by feedback problems.

CRAZY K

Spot on - you either get people who try and eat the mic and others that think they are on stage at the Apollo and go for walkies across the pair of speakers - feedback city I'm afraid!

The mic mixer is just a KAM 3 mic input with echo and a compressor - nothing fancy - this feeds into a Citronic CDMIO:4 MK5 mixer. Which incidently has no feedback system built in. This is then feeding a pair of Warrier active speakers.

I guess one way would be to get hold of a small feedback eliminator and place it between the output of the mixer and speakers, keeping a watchful on on feedback loops and only use it only when I do karaoke.

Thanks

[A1DL]

I take it there is more chance of someone walking in front of a speaker causing feedback

Well I guess that may be true, however the "double the number of open mics = lower the GBF by 3dB" is associated with the laws of physics rather than the laws of probability ;)



I'm not sure about giving the punters good quality mics so they can get abused. I don't understand the term "high SPL".

sorry, Sound Pressure Levels. Take a wired Shure SM58 for example, industry standard mic, been around 25 years, used and abused on loud stages worldwide, can be dropped, kicked around, used as a hammer, thrown in & out of trunks and it will still work. And they're cheap.


After doing a lot of searching via web search engines. There seems to be some debate as to use EQ versus a Feedback Eliminator.

Personally I prefer to use an EQ when mixing, either the sweepable channel EQs on a desk, or a dedicated parametric which gives greater control over what you're notching out, as you can narrow or widen the bandwidth accordingly. Not that I'm recommending you use a DN410 for Karaoke night at the Dog & Duck, that would be a little OTT :cool:

I 've never liked those cheap feedback destroyers, Behringer (surprise, surprise) do something like an Ultrazap Cillitbangerizer Pro that kills dead everything in and around the octave where feedback is detected. The expansion on release is equally as subtle as a fart in an elevator. Colleagues have discussed a Sabine unit, which apparently does a much more elegant job, I've never used one, however I don't believe the unit comes particularly cheap. I guess that Kam unit you've linked to would have closer characteristics to the Behringer.

[welby]

A1,

thanks for the heads up and technical info.

Yes the sabine would be OTT for the amount that I would require it.

Others mentioned are:

DBX
Alto

Does anyone know the difference or effectiveness of these units?

I would assume that the use of a parametric equaliser requires a certain level of skill in finding which frequencies are giving the feedback. I'm assuming there are more than one frequency that can cause feedback.

Maybe, for the times I do karaoke the best option would be to go for a decent mid-range one shot feedback eliminator - Simple to set up and control. Minimum fuss?

Thanks,

Mark

[welby]

Hi all,

being doing some tests and I can conclude the cheap mics are the culprit. I managed to borrow a decent Shure SM58 and guess what! Very little feedback if at all with good eq.

So my next question is where can I get two of these for a decent price?

I had a quick look around and they seem to be asking between £90 - £130 each!

Oh and what version do I go for? SM58 SM58S SM58LC etc etc?

[Babybob]

I've got a PG48 (around £40) and a PG58 (around £55) and in my opinion they are excellent for karaoke work.
As has been mentioned the SM58 is the industry standard but costs a little more so it's down to your budget but I would imagine the build quality on the PG series is just as good.
:beer1:

[Solitaire Events Ltd]

Hi all,

being doing some tests and I can conclude the cheap mics are the culprit. I managed to borrow a decent Shure SM58 and guess what! Very little feedback if at all with good eq.

So my next question is where can I get two of these for a decent price?

I had a quick look around and they seem to be asking between £90 - £130 each!

Oh and what version do I go for? SM58 SM58S SM58LC etc etc?

I think they are pretty much the same with the addition of a switch. £90 is not loads of money for a very good quality mic which will last you. As mentioned the PG58 is not bad either, but lacks clarity on the top end in comparison to the SM.