Re: Cause of a high pitch sound in our PA

[LouieAzcona]

check the EQ. baka nalingat ka lang 

[in_the_tent]

uy, wala rin yung orig message ko..

anyways, flat lang po talaga yung eq

[KitC]

Can you be more specific with the high pitched noise? Probable feedback? Disable all fx and aux sends first. Set all faders to infinity then bring them up one by one until you hit the noise.

[jcv]

I had a similar problem before.. for some reason when I turned off one of my voltage regulators (which is not connected to any of my pro audio devices), the irritating sound was gone..

but i'm not sure if we're talking about the same high pitch sound thing

[LouieAzcona]

nachek mo na ung individual EQs ng bawat input?
or ung master?

[in_the_tent]

Can you be more specific with the high pitched noise? Probable feedback? Disable all fx and aux sends first. Set all faders to infinity then bring them up one by one until you hit the noise.

sir Kit, hindi po sya feedback. tumutunog kahit walang aux &/or fx. pasumpong sumpong yung tunog nya. minsan meron minsan wala. me mga cables ako na kung saan dun lumalabas yung tunog na yun. yesterday nakakabit yung isang cable ko sa di box at lumabas yung ingay na yun. swinitch ko yung ground loop (ba yun) sa DI at nawala yung ingay. 2 mixers na ginamit ko yun pa rin ang problema. sa cables na yun ano? what could be causing it?

[in_the_tent]

nachek mo na ung individual EQs ng bawat input?
or ung master?

Paano pong check? kung saan nakapihit? flat lang sya. tsaka problem din sa ibang mixer yung ingay na yun. so i guess hindi mixer ang problema..

[fascinatedbymusic]

uy, wala rin yung orig message ko..

anyways, flat lang po talaga yung eq

What is the center frequency of this "high pitch sound" and specifics of your PA's set-up(paths)? Are you using it outdoor or indoor? Please advise.

[KitC]

swinitch ko yung ground loop (ba yun) sa DI at nawala yung ingay.

That alone already indicates the source of your problem. Trace that particular routing. Ground loops can be one source of the problem. Also check your cables for proper grounding; make sure the cable shields are properly soldered to their jacks and that the cables themselves are in good condition - inexpensive cables sometimes can have open shield circuits due to poor quality wires. I've seen some cables with only a few strands of wire that was supposed to pass for shielding.

Another possibility are EMI sources such as transformers, flourescent ballasts, CRTs and AVRs. Even computer power supplies that utilize switching rectifiers can be a source of high frequency noise. Laptop power supplies are also nasty sources of EMI/RFI.

Separate your audio cables from your power cables by at least 1 meter. If ever audio and power have to meet, make sure they cross each other at 90 degree angles.