Found source of a lot of noise on boat audio

[Rugburn]

Ive had this nagging noise over all my speakers whenever I installed a second battery with switch. Ive ready countless posts about ground, installing all at the same point, etc etc.

I thought Id share where I found the source of most if not all the noise hoping it might help others herding the same cats. The negative battery cable connecting the two batteries. Whenever I get any wire, even the ground for the head unit, I get a constant white noise. Ive since rerouted that cable along with the others since they dont play nice with each other.

Happy 4th people.

[rca]

I'm not sure I'm following. Which cables did you reroute to get rid of the noise? You still have the batteries connected together?

[jmvotto]

yeah I would be interested in that as well....

[Rugburn]

There is a single cable that connects one battery ground directly to the other battery ground (dual battery system). That cable is broadcasting a lot of noise.

[trayson]

so what did you do? Remove the cable? Replace the cable? ???

[Rugburn]

I replaced all the cables with longer, heavier, versions so I could route that cable along the floor, away from any of the other wiring. I currently am having a ground issue with the Fusion head unit. Fusion customer service has been pretty good. Im only one year in to a three year warranty. The only way I can silence the noise from my head unit is to ground the outer ring of an RCA preout to the same ground as the amps. Something internal has failed and the head unit doesnt ground like it should.

[MLA]

I think you are focused too much on the ground circuit with a dual battery system.

[Fastest1]

Ground loop potentials can be very tricky. In CNC machines they cause all kinds of nightmares like false limit switch triggering.

[jmvotto]

I think you are focused too much on the ground circuit with a dual battery system.

Suggestions..?

[MLA]

Suggestions..?

Its well documented in threads pertaining stereo noise and battery banks, that all the audio gear needs to share the same battery B+.

[jmvotto]

Thought the op ran the route of the source b+ and when adding a 2nd battery the noise got added

[Rugburn]

You are right jmvotto. No noise, single battery. Noise generating from ground cable, two batteries.


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[MLA]

Thought the op ran the route of the source b+ and when adding a 2nd battery the noise got added
Ive looked back through this thread and the OP's previous threads, and cannot find any mention of how the audio B+ cables are routed.


You are right jmvotto. No noise, single battery. Noise generating from ground cable, two batteries.

Thats correct. One battery = one voltage source. Two battery = a difference in potential that will want to eqaulize through the ground shielding. Disconnecting the ground link turns the house bank into a stand-alone bank. I see this as one more step in the diagnostic process, not the cause and final fix.


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[jmvotto]

So you are stating that the introduction of a 2nd battery with greatly increase the amount of white noise, plus make it more difficult to isolate the noise.

[MLA]

The simple act of adding a 2nd bank, is not the cause of the noise, not saying that at all. If the dual bank wiring scheme is not 100% accurate, unwanted noise can be induced.

[jmvotto]

would you assume the factory did it correctly ?