atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging sound system issue

I have a paging / sound system that went on the fritz a few months ago and am pulling my hair out trying to resolve it.

The system feeds 10 speakers 70v tapped at 4w and 7.5w on 5 wall mount speakers. Total draw is about 80W. I have a 300W Pyle (original amp was a bogen 300w) There are 5 volume controls and the wiring home running to each and then the separate speakers on each of the 5 home runs are inline (bus) configuration.

This config had been working fine for 4 years. They have CD player as sound source and paging on vox mute.

At some point in time the system started sounding fuzzy and then would go out. They turned it off and on an hour later and it would work ok for a few days and then go out again.

I put it down to the amp going and got the replacement. I put that amp in and it worked fine. They next told me that they had to put the master volume at 9 to get any sound out on the system.

I came back in and started playing with removing different home runs and in no instance did it start wiring properly. I also tried and Ipod as the music source and didn't get any volume. I've looked at wiring and speakers and can't find comprimise. I am thinking volume controls but can't believe all 5 are fried.

Can anyone give me some advise on what to do next?

Thank you.

Connect one good speaker and see if it sounds good. If it does then connect up each zone one at a time and isolate it down to the speakers from there. With the one good speaker on all the time it should not change volume or quality as you connect the rest of the load.

Thank you. 1 speaker at a time...

Look for a 'replacement' speaker that doesn't have a line transformer. Or an 'added' speaker that doesn't have a line transformer. (Ed the maintenance guy wanted a speaker in his 'shop' so he could here his pages) One more possibility. damaged cabling.

Ground faults? What is your load reading on the line? An impedance meter will come in handy for this one!

Lightinghorse has a great point...I've seen "Ed the maintenance guy" bring in an 8-ohm home theater speaker from home so he could have a volume control in his office. Well at 70V that's over 600 watts...imagine what happened.

Thanks folks, I am still dissecting the system. All good points...thank you. I have ruled out the extra speaker on the system. @tim10, I am a little challenged on meters but have used them. I'm not experienced enough with volt/impedance meters to make complete sense of them. Test equipment is key though. I have nailed many networking issues with Pentascanners OTDR and wire mappers. I never do a voice or data wire out without certifying them and as a result have had zero issues with wiring jobs. I will bring my radio shack multimeter and see what info I can get with it.

Your multimeter isn't going to help you much when troubleshooting speaker lines. What you really will want in this situation is one of these: https://www.sandman.com/wizard.html#ImpedanceBridge

It's expensive, but it could turn hours into minutes of troubleshooting. Think about how much work you do on paging systems and consider buying one if you do enough work on them.

Just start at 1 spk and look for wiring probs.
1 side shorted to ground by such as a hanger cutting into the wire.
Just straight break it down trouble shooting.

Paging system from hell...I've been following advise and started to get somewhere. I took out the 5 volume controls (I found one with reversed wiring that probably started this all). I reviewed the main section of the store and got 3 speakers going after checking wiring and the speaker connection. I leave it on for the store staff to monitor. They say the volume starts to go up and when they go to adjust the master on the amp the sound drops out and doesn't come back.

Could all speakers be fried? I know that 2 zones downstairs have static/garbled sound and know those need to be replaced. They aren't hooked up though. Just the 3 upstairs with a straight run.

It would be great to get the Sandman answer but I don't do enough to justify $475.

It makes sense to look at each component individually. I've been assuming the new amp is fine but am wondering about that now. I had it driving the old config. Could that now be damaged and seem to work for a bit?

Again, thanks for all the responses...it really helps a guy think he's not crazy after all.

It sounds like there may still be a bad speaker or miss wired volume control. But it maybe in the amp as you say when they adjust it the sound drops out. What is the sound source? They should be adjusting the input to amp not the master on the amp.