Speaker buzz

[jdpromo33]

On my 300 Sundancer, I'm getting a horrible buzz through the sound system speakers. It goes off when I switch the refrigerator off.
The system is grounded correctly so not sure if there is something I need to do to ground the fridge?

Any ideas?
Thanks guys

 

[tbirdvet]

I get the same noise through my cockpit speakers (not cabin). This is because my cockpit speakers run off of its own amp from the radio. The dealer ordered some filters(either ground loop isolators or power filters, not sure which). I believe the isolators are the way to go but will not know until they are installed. The buzz gets worse as more accessories are turned on (battery charger, frig., etc.).

 

[fc3]

obviously your speakers are drinking too much and getting buzzed. Cut them back and you should be OK. Otherwise, add some chokes to the power leads for the head unit and any amplifiers installed.

 

[LADY G 290]

I had the same issue as you on our 290 many years ago.
I am not positive now what i did but it was definetly a grounding issue with the amp.
I think it was called a "ground loop" condition and is caused
by components of the stereo system being grounded at different spots in the boat wireing. Not all of the grounds are
"equal" and it allows a small current to flow between them
and when your fridge cycles on you get the speaker noise.
Take the ground wire of your amp and try grounding it to a
different battery in the bilge. You may need a short jumper wire to reach another battery.The idea here is to be listening to the stereo with the fridge on with the buzzing noise and then you try different ground points to listen for the buzz to go away.When you find a point that the noise is gone then hard wire the ground to that spot.
I hope that this helps.
Happy Boating, LadyG

 

[jdpromo33]

I get the same noise through my cockpit speakers (not cabin). This is because my cockpit speakers run off of its own amp from the radio. The dealer ordered some filters(either ground loop isolators or power filters, not sure which). I believe the isolators are the way to go but will not know until they are installed. The buzz gets worse as more accessories are turned on (battery charger, frig., etc.).

Yes me too, I have 1 amp for the cockpit speakers as I'm running a big sub and 2 coaxial speakers and another amp for the cabin which also has another sub and 2 coaxials

I was also told about the ground loop isolators so I guess I will try that

 

[tbirdvet]

Here is one source for isolator (can also get at Radio Shack).
http://www.amazon.com/PAC-SNI-1-SNI..._1?s=automotive&ie=UTF8&qid=1274024467&sr=1-1

 

[tbirdvet]

The dealer just installed ground loop isolator on each amp (cockpit and swim platform) and all noise is gone. Model is SN-1 but I believe all others work the same.

 

[boatmailster]

The dealer just installed ground loop isolator on each amp (cockpit and swim platform) and all noise is gone. Model is SN-1 but I believe all others work the same.

no they are not
what they used is one of better ones