Business Phone Systems

Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Joined: Apr 2016
Posts: 45
Tucci Offline OP
Member
OP Offline
Member
Joined: Apr 2016
Posts: 45
New to constant voltage paging systems.
I have a customer with a Bogen C100, many speakers.
It has developed a loud popping and crackling noise from the speakers after it is on for 30 minutes or so and it is idle. Paging does not trigger it. Nor does it stop it.
The noise does not change with the knobs on the front. It seems to be worse on the 70V circuit, as once it starts doing it, it never stops. On the 25V circuit it will come and go.

I have it on the bench at the shop right now with one horn hooked up, and have only heard a few pops out of it.

It sounds just like a bad volume control potentiometer would sound on any other audio device. BUt again, twiddling the knobs does not affect it at all on this Bogen.

What is the typical cause of the popping noises when the system is idle? Is it a load issue?

Edit. I did relocate the unit to a different room to rule out power. The room it was in also had a lot of high draw devices in it and was not climate controlled, so I figured that couldn't be good for it.

Last edited by Tucci; 04/21/17 08:31 PM.
Atcom VoIP Demo
VoIP Demo
Joined: Jan 2007
Posts: 1,014
Member
*****
Offline
Member
*****
Joined: Jan 2007
Posts: 1,014
A couple of questions. Is it running at 70volts or 25 volts or both? When you say many speakers how many is that? The first thing I would do is check the total load the amp had on it. A C100 is 100 watts. I would make sure the total draw is less than that.


John 807
Joined: Apr 2016
Posts: 45
Tucci Offline OP
Member
OP Offline
Member
Joined: Apr 2016
Posts: 45
Originally Posted by John807
A couple of questions. Is it running at 70volts or 25 volts or both? When you say many speakers how many is that? The first thing I would do is check the total load the amp had on it. A C100 is 100 watts. I would make sure the total draw is less than that.

It was running on 70. I switched it to 25 just for hahas. Still did it, except it went from doing it constantly to the noise coming and going.

I'm not sure how many speakers are on it, didn't count. I just assumed it was going to be a bad amp, but where it doesn't do it on the bench, now I'm not too sure. Of course it loaded differently on the bench with only one horn instead of the many speakers.

I'm just looking for the most common cause of popping and crackling so I can start there.

Joined: Jan 2007
Posts: 1,014
Member
*****
Offline
Member
*****
Joined: Jan 2007
Posts: 1,014
I would measure the entire wattage draw using an impedance meter. It could be someone added speakers and you are now over 100 watts or an 8 ohm speaker was installed by mistake or one of your speaker cables has a leg going to ground. Personally I would start by measuring the total draw and go from there.


John 807
Joined: Apr 2016
Posts: 45
Tucci Offline OP
Member
OP Offline
Member
Joined: Apr 2016
Posts: 45
So I've read that I can use a regular DVOM to measure AC amps and voltage and work the watts from there...

Then check what the speakers are set to and see if it makes sense. I don't have the impedance meter.

Joined: May 2007
Posts: 5,049
Likes: 3
Moderator-1A2, Cabling
*****
Offline
Moderator-1A2, Cabling
*****
Joined: May 2007
Posts: 5,049
Likes: 3
If it's only a few speakers go around and check the taps on them and add them ll up. See if they're tapped for 25V or 70V. Make sure no one slipped a speaker without a transformer in.

If you've got too many speakers to do this comfortably, get an impedence meter and test the line. If it's under 100 Watts (and it should be under 80) then play music over the speakers. Walk around and see if one or more speakers sounds too loud or too low. Check their taps.

Work it from there. Check your connections and make sure they're mechanically sound. If necessary split the system in half. Run half the speakers (with music or test tone) through them and see if the problem is localized to one section or the other.

Let us know what you find.

Sam



"Where are we going and why are we in this hand basket?"
Joined: Feb 2005
Posts: 12,334
Likes: 3
Member
***
Offline
Member
***
Joined: Feb 2005
Posts: 12,334
Likes: 3
Bad amp. End of story.

-Hal


CALIFORNIA PROPOSITION 65 WARNING: Some comments made by me are known to the State of California to cause irreversible brain damage and serious mental disorders leading to confinement.
Joined: Apr 2016
Posts: 45
Tucci Offline OP
Member
OP Offline
Member
Joined: Apr 2016
Posts: 45
That's what I'm thinking, but it's quiet as a mouse on the bench. Again, though, there's only one speaker attached.

So far, no one has come forward with the most likely cause of popping noises on this type of system. That seems odd.

So far the consensus seems to be check the entire system to ensure that the amp is not over loaded. Does being over loaded cause popping noises from the speakers?

Joined: May 2013
Posts: 11
BWC Offline
Member
Offline
Member
Joined: May 2013
Posts: 11
I agree with Hal.

If you are really into bench teching, check the output section of the board for broken, loose solder joints, damaged looking components ie: output power resistors, transistors, etc...

If it is mostly solid state/chips, just replace it.

Joined: Apr 2016
Posts: 45
Tucci Offline OP
Member
OP Offline
Member
Joined: Apr 2016
Posts: 45
So I'm on site now. 26 speakers. No volume controls that I can find. Checked voltage and amperage on the 70 and the 25. Volume turned all the way down on the amp, 1 kHz test tone. 70: 24.8 v 1.18 amps for 29.3 watts. 25v: 10.5 volts .4 amps for 22 watts.
Still waiting for the amp to heat up to see if the problem occurs again.

Page 1 of 2 1 2

Moderated by  metelcom 

Link Copied to Clipboard
Forum Statistics
Forums84
Topics93,833
Posts636,789
Members49,649
Most Online5,661
May 23rd, 2018
Popular Topics(Views)
Today's Birthdays
AWhite, jnimmick, MarkTPN
Newest Members
Lazlo, devben, bubblegum, Carl Arnold, Marjan Shaw
49,649 Registered Users
Top Posters(30 Days)
ramo 13
pvj 11
Toner 9
Who's Online Now
1 members (Curlycord), 38 guests, and 19 robots.
Key: Admin, Global Mod, Mod
Contact Us | Sponsored by Atcom: Business Phone Systems | Terms of Service

Sundance Communications is not affiliated with any of the above manufacturers.
©Copyright Sundance Communications 1998-2023
Powered by UBB.threads™ PHP Forum Software 7.7.5