Buzzing sound from one speaker

[Gweedo]

Good morning, wondering if anyone has experienced this or have an idea of what the problem may be.   Several months ago I heard a small buzzing sound coming from one ceiling speaker.  We never watch tv one because I need to replace the satellite and normally we may watch a movie.       
 

Anyhow when we were boon-docked I had the portable generator running and then I turned on the coach genny to transition.  The buzzing from the speaker became noticeably louder until I turned off the portable genny.      Any ideas on what could cause this?  No tv or stereo turned on.  
 

Thnx 

 

 

[cbr046]

Sounds like EMI coming through the power wires for the system feeding the speakers.  If so, an EMI filter would fix that.  Do you still get the buzzing when running off the inverter?

What happens when you swap the speaker with another speaker?

So many possibilities.

- bob

 

[DBRV.0]

20 minutes ago, Gweedo said:

I heard a small buzzing sound coming from one ceiling speaker.  We never watch tv    

I had the portable generator running and then I turned on the coach genny to transition.  The buzzing from the speaker became noticeably louder

 

 

I'm going to return to my younger days when we had carburetors, points and condensers.  I had a VW bug that would buzz the radio speaker in my dash.  The faster the engine rpm, the higher pitch of the buzz.  That's when I learned about quality spark plug wires.  I don't suppose that both of your gennys are gas, are they?  Therefore they use spark plugs?  The physical reason for the interaction with speakers is that bad (or damaged) plug wires create EMF, and speakers by their nature are designed to amplify small (micro) currents, including those caused by induction (from the EMF).

There are three ways I can think of to fix the problem.  (1) use high quality spark plug wires, or perhaps just replace if they are old or damaged,  (2) twist the speaker wires, (3) move speaker wires farther away from the EMF source.

[Gweedo]

Thnx, no noise on the inverter and I have not r tried to swap the speaker. I can try this when we return, out of state for a few days without the rig 

where would an EMI filter be placed?

 

I use a small Honda 2200 outside.  But I had this several months ago plugged into shore power 

[cbr046]

5 minutes ago, Gweedo said:

I use a small Honda 2200 outside.  But I had this several months ago plugged into shore power 

Honda 2200 power should be very clean (sinusoidal, no spikes).  The inverter probably isn't as clean as the Honda.  Shore power can be noisy also.  You'd be surprised how noisy shore power can be!  Any AC device with a motor (residential refrigerator?) can generate spikes. 

An EMI filter would be in series with the power lead for the entertainment device (not sure what you're using for an amplifier).  On our older Endeavor the ceiling speakers are fed by the 12V dash radio.  All of my speakers have rotted suspension (cloth like material from cone to outer frame).  No bass to speak of and can cause a buzzing, but only with signal applied.

I'd swap speakers first.  Easiest to do to see if it's something odd about the speaker. 

- bob

[Les Hurdle]

If it is only one speaker it is unlikely to be emf etc [in my humble opinion].......... if the pitch of the 'buzz' does not rise or fall with rpm, likely a blown speaker or a mousey got your wires.  As suggested, move or swap wires to another speaker.