Wiring location for an Amp?

[Ghost Crew]

I'm installing a digital alpine amp (50 amp in line fuse) to better power my 4 existing speakers. Was going to install the amp on side panel by the driver feet, off the floor on ledge. I'm new at this and wanted to know if I could wire the positive of the amp to the power connection on the power bar and the negative to the ground bar, all under the dash. Would be so much easier than trying to run line down through the ski locker to the battery.

Thanks in advance and love this site, use it 4 or 5 times a season to trouble shoot the boat.

[MLA]

The amp's GND needs to go directly to the battery GND and the amp's B+ needs to go directly to the battery B+ or boat side ("C" post) of a dual-battery if applicable.

[Earmark Marine]

Ghost,

Just as stated above you need to go battery-direct. The existing helm supply cable and connectors are only rated to cover the factory accessories and very little more. With an amplifier capable of a maximum draw of 50 amps, you will want 4-gauge pos. and neg. cables. You also have the option of installing the amplifier much closer to the battery(s). Long RCAs are much less expensive than long primary wire.

David

[Rmattajr]

Ghost,

Just as stated above you need to go battery-direct. The existing helm supply cable and connectors are only rated to cover the factory accessories and very little more. With an amplifier capable of a maximum draw of 50 amps, you will want 4-gauge pos. and neg. cables. You also have the option of installing the amplifier much closer to the battery(s). Long RCAs are much less expensive than long primary wire.

David

David do you ever recommend grounding to the engine? I have some clicking in my speakers and wonder if i am picking it up from the battery ground?

[Earmark Marine]

David do you ever recommend grounding to the engine? I have some clicking in my speakers and wonder if i am picking it up from the battery ground?

Not really. A well-charged battery can serve as a noise suppressor.

Is the clicking coming from the sonar...and gone when the depth finder is disconnected?

The key to noise elimination is having every audio component in the signal path sharing the same B+ supply point and sharing the same ground point. Specifically where that shared point is can be secondary in importance but it is usually close to the battery.

David

[Rmattajr]

YES!!!!!!!!!!!! haha clearly this is an issue. So i could hear and feel the clicking on the depth finder on the bottom of the boat and when i disconnected the wire from the box under the dash the noise stopped at the bottom of the boat but the same 3 click noise can be heard at low levels in the speakers. Is there a solution for this?

Not really. A well-charged battery can serve as a noise suppressor.

Is the clicking coming from the sonar...and gone when the depth finder is disconnected?

The key to noise elimination is having every audio component in the signal path sharing the same B+ supply point and sharing the same ground point. Specifically where that shared point is can be secondary in importance but it is usually close to the battery.

David

[Earmark Marine]

YES!!!!!!!!!!!! haha clearly this is an issue. So i could hear and feel the clicking on the depth finder on the bottom of the boat and when i disconnected the wire from the box under the dash the noise stopped at the bottom of the boat but the same 3 click noise can be heard at low levels in the speakers. Is there a solution for this?

Depth finders can go bad. The gauge or dash module might have a compromised ground. The shielded cable going from the dash to the hull transducer may have a nick in the cable shield down in the bilge. One of the sonar components may be defective at this point and need replacement. A connector may not be fully seated.

There could be several ways to proceed. Start with the isolated amplifier with no inputs and work backwards in the signal path until you add a component and the noise reappears.

Or, take a cheap and long RCA cable and cut of the end opposite from the amplifier. Strip off the jacket and 12" of shield leaving 12" of center conductor exposed. Plug the cable into the fullrange amplifier, turn the amplifier input gain to full and move the raw end of the RCA cable around as a noise sniffer until you narrow the source location.

David

[Rmattajr]

Thanks David,

All very helpful,

[Ghost Crew]

Thanks for the detailed feedback. Looks like I've got some wiring to do this weekend.