Karaoke Forums

I host on others systems, and one which has always caused me problems, I noticed (while out socially) is creating a "crackly almost sounding like white noise" noise, predominantly when someone was singing into the mic. Although it appeared to happen randomly, when the noise did occur it drowned out all the vocals and most of the backing music. The person running the system and his helpers, assummed it was feedback, but to me it sounded like the mic was searching for a frequency.

The microphones are the Kam KWM 1920 Dual UHF http://www.udmdjstore.co.uk/details.asp?ProductID=27560

Can anyone suggest what the problem may be and how to solve it?

No, but I can tell you that I wouldn't automatically assume it was a microphone problem. I would change channels on the mixer and see if it persisted. Then I would change the batteries in the wireless microphone and see if it ever happened when they were fresh.

Once I had tried those things, I would check the antenna placement and connections. Finally, I would suspect the mic.

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[color=#ffff55]Mickey J.[/color]
Alas for those who never sing, but die with all their music in them.
-- Oliver Wendell Holmes, Sr.

It is white or thermal noise which is caused by an amp turned wide open or the AGC turning a receiver wide open. The RF output on that mic is low which can be caused by.

Bad antenna or bad connections from antenna to ckt brd.
Check the battery clips. Are they corroded with alkili?
How far is the mic from receiver? Try putting the receiver higher or closer to the singers.. It,s not behind the singers is it?

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As I use powered speakers, the whole amp thing goes above my head... when you say "an amp turned wide open or the AGC turning a receiver wide open" do you mean they are on maxium volume?

The reciever is low down and behind the singers, but on average the singers are only four meters away from it. This is also only a recent problem. (It's occasionally done it before, but for half a second and about twice a night, not every other song and for about 10 seconds a go).

The owner loves his system and thinks it's the best in the area (can't blame him, i love mine and think highly of it too ) but sadly the only thing he wants me to do is adjust the volume and the amount of echo on the mixing desk.... (i do, but only subtle things like an individuals EQ which i reset at the end of the night). I'm also aware that if anything goes wrong and i have adjusted the system the ten "experts" that "play" with this system on a regular basis, will blame it on me. So I'm hoping to point him in the right direction to fix the problem, rather than fix it myself.

Ps If it is white noise, which I think it is, was I in the right when I rolled my eyes at one of the "ten" experts who moved the monitor speakers to face out to the audience?
Edited to add something... then I decided not to.

Is there 2 mics and one working? It sounds like the mic in question has a low output in regard to radio frequency. I would at least move the receiver to the side of the area where it is not behind the singers. A true test would be see how far the mic will work from the receiver.

My reference to the amp was general statement but hints that the overall gain structure of that system may be too high.

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From what i can gather (i was sat in the audience), one mic produced the majority of the noise, and the other produced some but not nearly as much.

From previous nights working there, one mic cuts out about six meters away and the other ten meters away from the stage.

From your posts, I am suspecting it's a variety of things that are causing the problem, I've thought for a while the set up is strange, (the wrong type of speakers, the settings on the mixer and the amp seem inncorrect), but because I don't understand PA systems that well, I don't have the knowledge to back up my suspicions.

The gain probably is too high, but i suspect it's because the karaoke tracks play really quietly compared to the DJ songs (It's all on computer... except for one CD player).

If the problem still persists when i'm next working, I'll put forth your ideas about gain and moving the receiver. (Though I'll claim them as my own, when it all starts working smoothly again).

I repeat the call about power. When power sources are at all suspect, they are the first place to look and the most likely cause. Contact corrosion, moisture, etc. are by far the most likely problem. *Particularly* if the unit worked fine before.

Electronic circuits of today rarely degrade -- they work or not. Power and antenna contacts on a frequently-dropped-and-banged item have to be the most likely source of the problem.

_________________
[color=#ffff55]Mickey J.[/color]
Alas for those who never sing, but die with all their music in them.
-- Oliver Wendell Holmes, Sr.