Stereo Noise Indentification

[intrlaz]

Hey all,

I just completed installing 2 Alpine amps, WS-420, new tower speakers and new in boat speakers, and I am having noise issues. I have searched the site and believe I have installed everything in a way to minimize noise.

I have two batteries, one cranking and one deep cycle, both grounded to the engine block and both hooked to perko switch.

I have 1/0 gauge power wire from the common post of the perko to the 4 gauge distribution block at the amps, 1/0 gauge ground wire from another disto block to deep cycle battery.

Ran new 12 gauge wire for the deck and grounded the deck at the distribution block where the amps are grounded.

Signal wires routed away from power, tried to minimize running them next to each other.

I am getting noise while running with the perko switched to the cranking battery. I have not tried running in the "all" position. The only thing I could think of was possibly a poor connection from the deep cycle to the engine block. For some reason that wire is only 4 gauge.

Thanks for the help.

[intrlaz]

I ran the engine solely on the deep cycle (that the amps are grounded to) and this definitely cut the noise down. Could be my problem.

I don't believe it is a signal cable issue. I ran a single RCA from the WS-420 and then from the head unit. No change in noise on either

[Mikeski]

almost all the time the source of engine noise in a boat is different battery sources

I see it all the time, most of the time from shops, where they install amps and run them off the stereo battery leaving the deck on the starting battery. The difference in voltage will be seen by the amp as an audio signal, it's amplified and sent to the speakers.

connecting all of your audio system components to one point of power and one point of ground almost always eliminates the problem

If you must have the system work off the key you can sometimes just hook the red wire to the deck to the keyswitched hot. If this causes noise you will need to add an isolation relay.

[intrlaz]

Agree with the point on the deck ground. I did run a new ground and power from the source unit to the amp distribution blocks. There is still a considerable amount of noise

[AuMDLST]

Noise

I believe this has been covered several times. If I remember correctly it is in part due to the
ws-420 and the gains on the amps. Just about everyone that installed a ws-420 had some complaint
about hissing/noise. Earmark usually explains the situation and possible solution.

[intrlaz]

Hmm, I will do a search on the WS-420 and see what I find. Only thing is I bypassed the WS and went straight from deck to amp with no change in noise. Gains on the amps are at about 2/3

[EarmarkMarine]

Intriaz,

I'm only repeating what Mikeski has already stated. I'll just put it in a little different terms and a little more long winded.

All grounds, battery-to-battery, helm buss, engine block and amplifiers are common. If you've got adequate wire gauge and quality connectors, its probably not the issue. However, it is good to ground the source electronics including the EQ, close to the power terminals of the largest amplifier. This loop is the potential difference that would concern us the most.

If you're using a dual-battery Perko switch, then there is only one way to go. Nothing positive should go battery direct. Everything including the alternator/starter cable, helm buss, amplifiers and all source electronics should be connected to the Perko switch common post. The only exception might be a float switch/bilge pump if your boat is stored in water or a battery charger.

As a trial you can pull the source electronics power and memory off the factory harness and go directly to the biggest amp positive power terminal. Also, as a trial, bypass the EQ or other processors.

All of this is a waste unless you've first verified that both batteries are fully charged.

Overgaining the amplifiers is a common issue.

This is a good start in isolating the problem. Hopefully its enough.

Round two if necessary.

David
Earmark Marine

[intrlaz]

I decided to use the CMD6's fixed audio output along with the WS-420, that way I dont have to control the volume on the deck and EQ. Turns out this allowed me to turn the amp gains all the way down, which eliminated the noise.

Thanks for the help everyone