Tower Speakers Buzzing when Navigation Lights turned on....

[Alerberg]

All,

I had an ambitious start to the offseason... I mounted a Lumitec Seablaze 3 underwater LED light on the transom of my 2015 Moomba Mondo as well as two new MB Quart 8" tower speakers and a JL audio amplifier that I mounted next to the battery. I connected the amp power and ground direct to the battery and also connected the remote wire. The speakers are working great except when I turn on the navigation lights/curtesy lights in the boat (which also powers my underwater LED light) in the back. As soon as I turn on the lights I get a serious buzzing sound coming from the tower speakers.

Possible Causes:
1. Could be a wire that I accidentally pulled the sheething off of during install. It is one of the wires going to the tower speaker, I just shoved it back into the tube. It was down to the bare wire, I learned an important lesson, don't ever use needle nose pliers to pull wire.

2. Could be my new LED Underwater light causing some interference?

3. Could be the location of the amp, I mounted it next to the battery on the little divider board by the battery switch?

Anyone have experience with this????

Al

[MLA]

As to #1, if you indeed pulled the insulation off, down to bare copper wire, theres no putting it back in. You mean you shoved bare wired back into the tower tube? Can you clarify exactly what happened here? Bare wire WILL be an issue for the amp

#2, sure. LEDs can give off a pulse frequency that can leak into the speaker output.

#3, likely not the amp's location, but maybe the location where the amp's B+ cable terminated. Does this boat have an in-boat amp? does this boat have a dual battery bank and switch setup? May be worth sitting down with your JL amp dealer, and getting some setup and tuning details for preventing noise. Once those are checked. corrected, then time to go deeper.

[Alerberg]

Decided to run a test... I took a second battery and wired the amp to just that battery, walla... buzzing went away. So I am now assuming it is some sort of ground loop problem. Can I run dual batteries? If I connect them together will the buzzing come back? Hope this helps.....

Al

[MLA]

Sounds like you made a significant find, so stay on that path, however, I would not jump in just yet and install a dual bank setup as the fix.

[stevemarich]

I had a similar buzz when would turn on factory underwater lights, I have factory dual batteries,I believe the what fixed my buzz was , the head unit power and remote power we're tied together, for whatever reason when I changed it so all amps and head unit remote power we're on same circuit it went away.

[Alerberg]

That might be a problem, I have two amps located in different parts of the boat. I am looking into a dual battery setup but only need to charge the second battery somehow.

[stevemarich]

60 or 100 amp isolator , most auto part store should have one

[MLA]

I have two amps located in different parts of the boat.

Their physical mounting locations may not be the issue so much as how and where they are wired as well as how the head unit is wired into the mix.

I would pass on a diode style dual bank isolator and go with more traditional marine dual bank switch or similar. A couple of the cons:
voltage across the diode
no means to use the house bank as backup cranking battery
All boat loads wired directly to battery with no master disconnect
ground loop noise may not be eliminated.

Id consider taking the off season to reconfigure the audio system so both amps are close, use a common trunk line and branch line, proper circuit protection and wired in a manor to reduce the chances of unwanted noise.

[Alerberg]

Would a blue sea systems ACR fix my problem? In other words, have two batteries, one starter, one house. Use the ACR to charge only as needed? Or will I still get noise in the system? I would prefer not to relocate amps and rewire everything. My sub and amp (wired to distribution panel under helm) are on one side of the boat while my tower speakers and other amp are on the other side of the boat wired direct to the battery. If I were to move amp, I would have to run speaker wire all around boat as well as RCA's, would prefer not to do that if I don't have to.

[MLA]

The blue sea acr setup is one of two commonly used dual bank setups. It alone, will not cure the noise any more then a traditional 1/2/BOTH/OFF switch. Adding a dual bank system is likely not the fix. However, through the process of properly rewiring in order to correctly configure either switch, there is a chance that the noise issue would be resolved. As stated above, I would resolve the noise with the system as is, then move forward with a dual bank setup. I say this because, in a perfect world, th lights suspected of inducing noise, would be drawign off the house bank along with the audio, similar to now with the current single battery.