Noise in New Boat Stereo System

I have just replaced all of the stereo components in my boat and am getting a lot of "feedback" (not sure if proper term for type of noise) or white noise coming from the speakers. I have re-wired everything twice, and it is driving me crazy. It is not a small amount of noise, it is noticeable until the volume of the music is very loud. Any help or direction is appreciated. I will lay out what I have installed and what I have done to try and eliminate the noise. Boat is a 2000 Ski Nautique Super Air PCM 350 Components Head Unit: Alpine UTE-62BT Equalizer: Wetsounds WS WS420-SQ Amp: Boss MR1950 5 channel amp - powering everything In Boat Speakers: 4x Alpine SPS M601W Wake Tower Speakers: MB Quart NT1-116 Sub: JL Audio 10" W1v3v-4 - Layout Head unit has not been mounted, is just sitting on the floor right now, until I can get this noise figured out Same with the equalizer Amp is mounted to the backside of the bow walkthrough wall, behind the lift up seat 4 Alpine in boat speakers mounted in stock locations, two on port, two on starboard side. 2 MB Quart speakers mounted to aluminum monster wake tower Sub is mounted in small fiberglass box in the space behind lift up seat with the amp Wiring I had all of the wires ran cleanly through the boat. Unfortunately that meant running some speaker wire alongside the amps main power and ground wires. This has been all "un-ran" and all the the wires are now freely sitting on the floor of the boat, to get them as physically far away as possible, to eliminate the possibility of any interference happening. Still no difference in the noise All wires are brand new, speaker, power ground, RCA, remote Wiring method: 4 gauge power and ground straight from the battery, 60A fuse on power wire 4 gauge goes into a 4-8 gauge distribution block for both power and ground. I wanted to leave it open to add an amp(s) in the future, and the amps is "marinized" so all of the wires coming off the amp are stubs to keep it water proof, and I didn't think splicing a 4 gauge wire into a 8 gauge wire would be a very clean connection. 14 gauge power and ground ran straight from battery to head unit, which is then spliced to the equalizer Remote turn on is ran from head unit to equalizer/amp 2 channel RCA ran from head unit to equalizer 6 channel RCA ran from equalizer to amp 16 gauge speaker wire ran to all speakers "front left" channel is wired to left tower speaker - 4ohm "front right channel is wired to right tower speaker - 4ohm "rear left" is wired in parallel to the two left in boat speakers - 2ohm "rear right is wired in parallel to the two right in boat speakers -2ohm Sub is straight wired to amp - 4ohm Battery is brand new Procedure: Has only been powered on with just "key power" as the boat is winterized and I won't be starting the motor for a few more months So alternator whine is out Noise comes from all speakers, almost equally, slightly worse on tower speakers Noise exists as soon as power is on to the head unit, equalizer, and amp. Noise exists with no RCA's attached to the amp Noise exists with a another new set of RCA's Noise exists in any/all speakers, when any individual speaker is unplugged, noise remains in the existing ones plugged in still Amp gain is set at maybe 20% Attempted Solution/Troubleshooting Removed all wiring from "proper" routing to free them from any power interference Replaced all old wiring with brand new wires Removed all components from the battery - The only thing being powered on the entire boat right now is the stereo, there is only four wires total coming off of it, the stereo is basically a stand-alone system now, still getting the noise Added secondary ground cable from battery to block, and or motor frame mount (tried both, and individually) - No difference Switched out existing amp with a fairly new alpine 5 channel from my truck that works fine in that application, wired to that - slight difference in noise, marginal Bypassed equalizer, ran RCAs straight from head unit - no difference, marginal at best Some of the wires a a bit messy in the pictures, but this is on purpose now, to make sure I can see where they are all routed and make sure nothing is touching or wire sheeting came off etc. Aside from where everything comes together at the amp, all the wiring is as physically far away as I can make it. I am no audiophile, or electrical engineer, and non of this equipment is top of the line, but all brand new equipment, all brand new wire shouldn't be doing this. Any help/suggestions/methods of testing/troubleshooting tips would be helpful. Thanks you. Power/Ground at Battery (Second battery attempt, you can see the first the in background) Power/Ground cables (on the floor for now) RCAs at amp Power/Ground distribution blocks Power/ground at amp Speaker wires at amp Amp Equalizer Head unit In boat speaker Tower speaker

I cast my vote for the Boss amplifier.

A probable cause. I know it’s a crappy amp, that will not output anywhere near what the wattage rating of it is. But it should do the job, not looking for crazy sound, and it is fully marinized, hard to beat for less than $200. Except I switched it over to another amp that I have, that I known functions properly, without any noise.

So you too are voting for the Boss amplifier, right?

No, because I got the same results with a completely different amp.

Except I switched it over to another amp that I have, that I known functions properly, without any noise.

That was in reference to the amp functioning properly, without noise, in another setting. Wiring it into the boat system nets the same results.

Ground loop isolator...you never know it might help lolSolder, tape, repeat!

I could try that. But don't think it will help, as it is the same whether the rcas are plugged in at all or not.

Disconnect all speakers from the amplifier. I know this is not likely since you are in a boat. But if you ground a non bridged speaker wire it will cause noise as you are experiencing. Connect 1 speaker at a time and see if the noise is there.