sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging Speaker Noise

All the PRO's including the phone company are no help. Velcom, phone company and a audio video specialist have told me they don't know either. Phone company has been here many times, in fact they installed the system.

If you know any PRO's in the north western WI or ST Paul MN area I would be more then willing to call them.

OK, let's think about this. SOMETHING has changed. It's "PROBABLY" not in the paging system. It's interference 'in the air' so to speak. Has ANY other equipment been added, worked on, installed, or removed, in or NEAR the building? AND THINK ABOUT TRANSMITTERS OF ANY TYPE!

Suga Ray Jay- our Tech Support team here at Valcom is grasping at straws, as is everyone else! Let's try something. What if you lift the speaker (while still connected) above the ceiling grid. Does the noise go away?

If I'm not mistaken a AT&T cell tower went up. Not sure how long ago. We added a new phone and voice mail controller, but that was at least 4 to 6 months before the noise started. I have our IT person looking into dates and equipment that was installed around that time. Equipment that we have and has been running before this:

Computer Servers ( Wire less )
Video Surveillance ( I believe some is wire less )
Heating and cooling Zone controller ( Damper motors )
1 Bathroom vent fan, runs constant.

The noise is not constant. I could possibly have to stand on a ladder for hours waiting for the noise. I suppose I could take every speaker tile and turn them 45 degrees and set them back on top of the grid instead of in the grid. Would that give you what your looking for or would the speakers still be to close to the grid?

Awhile back, a customer of ours experiencing a similar issue, determined the noise was present on the ceiling grid and being induced into the speaker. This noise was constant, however and each time the ceiling speaker was lifted above the grid, the noise stopped. The customer ended up placing rubber or plastic tabs at each of the 4 corners to provide slight separation from the grid. Again, grasping at straws.

Definitely agree with other members here that have stated the noise is from an external source and not that of the paging system.

Grasping at straws is better then pulling hair, any and all ideas are welcome.

I don't think its from the paging system either, its just coming over it.

Is the concept to get the metal frame of the speaker isolated from the metal grid ( I'm 95% sure there is no metal on metal contact )? Or are we just elevating the entire speaker above the grid, as in to brake a RF field?

Let me take a stab at this. You say that you have disconnected the audio pair at each speaker leaving only the power and the noise persists. It's very possible that a noisy component in one of the speaker amps is putting noise on the common power wiring which in turn is picked up by the other speaker amps. The only way to find the one that is causing the problem is to disconnect each speaker completely first in groups then, when you have it narrowed down to a group, one by one.

And sorry Valcom, I know you make quality products that I have used many times but this problem illustrates one of the reasons why you should use a 70 volt system with this many speakers.

-Hal

Lifting the speakers from the grid is to isolate vibrations not metal to metal. I had a wall speaker do this once caused from a bad bearing in a ventilation fan. The fan would vibrate the wall and the speaker cone would start vibrating causing a loud static like noise. I doubt this is the problem here but it may be worth a try.