I have a customer that's having a problem with a pop coming thur his speakers every time he turns his cieling fan on.It also pop's when the refigerater water dispenser is working. Has anybody seen or heard of this? Is there a fix?

Hi Tom,
Sounds like an induced voltage problem.
Easiest way to fix it is to move the speaker wiring away from the mains wiring supplying the fan and the refrigerator.
This might be easier said than done, if it shares the same hole in the dwangs in the wall framing.
Hope this helps.


Mike.

thank's for the advice I'll check it out and let you know what I find.

I'd also check around for bad ground connections.

I would help to know a little about these speakers like where are they, how are they connected and to what.

-Hal

Or it might not be the speaker wiring at all. For example, if his amplifier is on one circuit, and his preamp and CD player are on another circuit that happens to be the same as the ceiling fan and refrigerator, then it wouldn't take much of a spike on that second circuit to generate a difference in ground reference in the line-level signal going to the amplifier, thus resulting in a pop at the speakers.

I've heard that "pop" too from ceiling fan controls. It's an arc in the control as it goes from one speed to the next. Cheap control. As to the fridge.... I don't know. I would guess it is the switch mechinism not supressing the arc enough. For the fan, I'd try a different control. For the fridge......again, I don't know.

I'll be going there friday so i'll keep you updated.Thanks for the Input.

tomselectric,

if it is contact arc, this solution has stopped the disturbance of many TV sets, MW receivers, etc. from central heating thermostats - and could help your fridge etc.

M.

just got word from the tec, everything was good and tight including all the grounds. there were no speaker wires going thru any holes.No wires were bye any speaker wires. we took the speed controls off all the fans and tried switches but it still made the pop. it is only coming thru the sub woofer. any ideas? I told he to try another sub woofer thinking maybe it,s the speaker itself.

What kind of installation is this- home theater, whole house? What kind of sub woofer- self powered or voice coil? What is the other equipment?

-Hal



[This message has been edited by hbiss (edited 01-21-2005).]

is the sub powered from a different circuit, possibly the one that serves the fan and refrigerator? if not, could it be sharing the neutral on a multi wire circuit?

Well, if it is a powered sub with it's own amplifier inside of it it would mean that it requires power and there is one or two unbalanced audio lines going to it. If the sub is located away from the main equipment it is usually plugged into the nearest receptacle. This can cause a ground loop through the equipment grounds and the audio cable shields assuming that everything uses 3 wire line cords.

Again I am assuming here, need more information.

-Hal

The kind of noise you're talking about usually gets in through the amplifier.

There are two pretty common ways that kind of noise gets in.

One is through the amplifiers power supply. If that is the problem you can reduce or eliminate it using a filter on the AC line. I'm calling it a filter because "surge protector" could mean just about anything. But a "real" surge protector (one with at least 12 db per octave responce) is actually a filter. If you have one or want to get one, plug the amplifier into that and see what it does.

Another is inductive coupling. Usually this would happen in the preamplifier section of an amp. Like with the old phonographs (member those) the preamp is very sensitive. If that is the problem you might be able to hear a car's ignition come through the speakers. You might be able to test that by lighting a lighter with a piezo electric ignighter near it.

Another thing you can do is to interconnect the chassis of connected components. If it's a ground issue that will make it stop. But if it does there may be grounding issues in the building you might want to check out.

A new amp might fix it too.

An arc or spark is also a form of RFI. Try a ferrite ring on the power lead to the amp or equipment used.

SimonUK.