Our workshop PA system has a buzzing noise?

Question

The workshop PA has two 'speakers' shaped like a megaphone, you know? Anyway, they are making a buzzing noise even when I am not paging anyone. Its just a constant buzz, never done it before, have tried turning down the volume on the phone (its run through our phone systems).

Any suggestions as to what it could be?

Thanks heaps

Answer 1

prob an overhead light ballast going bad that is near the wires to the speakers.  florecent lights will do it everytime

Answer 2

Buzzing sounds usually point to problems with CABLES.  Maybe they are loose-fitting or worn out.  Replace the cables, if that doesn't work, it can be several other things:  Interference with radio waves, or even electronic defect.  Both of those need to be fixed by a professional.  Try changing the cables first, though.

Answer 3

i set up a pa system on my truck. and i had come across this problem. you need to make sure the system i grounded.  The actual PA system, not the speaker, probably needs to be grounded.

Answer 4

Buzzing is usually indicative of something begining to breakdown in the system. Generally, the hum is from some small amount of current bleeding into the amplifier. This happens often times when separate microphones are used, and the push-to-talk switch begins to wear out. On systems that use phones, it can be the PA select switch, the handset or cord.  It could also be the volume control, as potentiometers begin to wear and leave a small amount of debris inside.

The problem can also be caused by the environment the PA system is located. In industrial areas, dust accumulation can cause breakdown, as well as high humidity, chemical vapors and such. Or, it could just be getting old and worn out.

Answer 5

reset it

Answer 6

First thought is that an input cable has become partially detached, loose connection, especially if it's a mic cable.

But if you unplug the input cable entirely, and the hum is still there, then most likely a filter cap in the power supply has gone bad.

If you unplug the input cable and the hum goes away, but comes back even when the cable is securely plugged in, then it sounds like you added an input somewhere and introduced a ground loop into the system.  One way to test that theory is to flip the power plug around to see if it goes away.  (On a three-prong system, you'd need a 2-prong, unpolarized adapter to flip it around.)

Answer 7

alliens

Answer 8

Your system has a "hum"?  Then needs grounding and better wire shielding.