Amp install woes... Or maybe not?

[JerEazy]

So i finished stage 2 of my sound system install this weekend. So, this chronicles the joys of my first amplifier install.

(links to what I used will be at the bottom of the post.)

Originally the boat just had 4 wal-mart speakers and what the first owner called an "amp" with a Line In for hooking up his phone. Bluntly, it was crap.

So first thinig i did was install a JBL Prv 175 direct connected to 4 JBL MS6200's (60w rms 180w peak) a HUGE improvement over the last pieces of crap that were in there. But it just lacked the OOomph I like, and i would have to crank it almost full volume to hear it while underway. The PRV 175 is only rated to 20w rms to each speaker (45w max).

So I purchased the JBL M6004 Amplifier (60w RMSx4) to match output with the speakers. I'm not normally a "It's gotta match!!" kind of guy. But it just worked out that everything is JBL on this install. The Amp being water-proof was a huge bonus.

My first concern was where to mount it. I wanted air-flow to keep it cool, but i didn't want to make a long wire run for the power to it (hindsight is 20/20 on this...) . So I decided I would mount it in the stern under the hatch where I have my batteries, switch and oil tank. This would normally be where the "changing room" is - but I don't change a lot on the boat. And having the battery weight on this side ballasts out the gas-tank on the opposite side (which when full still creates a listing effect.)


So step one was to figure out how to mount it. I took a piece of marine plywood and cut it to size of the right wall of the compartment. I then covered that in outdoor carpet to match the boat.

This is where i mounted the amp and the circuit breaker. I did not want to use an inline fuse because in my experience, they are never water tight. And i've only had issues in the past.

Using 8 AWG tinned cable, heat-shrink water proof connectors, and stainless steel staples and screws (more on this later) here is my pre-mounted amp and breaker. I used 1/4" spacers between the amp and the carpet/board to allow for a bit of airflow and the keep the heat off of the carpet a little bit.

(See the issue yet??)





After that was installed it was time to mount that inside the boat, run the RCAs and speakers and hook up the power and ground.

Mounting wasn't too difficult. But (back to the stainless screws) just because they are stainless, does not mean they are strong. I snapped the heads of 3 of them just screwing them into the holes I pre-drilled. Make sure you get QUALITY screws, not just STAINLESS screws. So after it was mounted and the cables and speaker wire had been run, the last thing I did was re-install the battery switch....

Now the issue may be apparent...



I did not think about where the cables for the switch were going to go. So they run right across the top of the amp. Now, I know amps get hot, but i'm not worried about them melting the cables. I worry about interference and maybe some melting issues down the line. So of course now all I can think to myself was "why didn't I mount the amp on-top?"

I thought of some reason while I was actually planning, but damned if I can't remember it now. So my only REAL course of action (that doesn't involve me completely re-running the speakers and RCAs) is to lengthen the positive cables from the battery and run them up and around the side into the switch. Which will be what I do next weekend.

On the bright side, everything is hidden with the cover down - and I have easy access to the whole thing just by un-snapping the cover






So, for those of you thinking of doing the install:

It is a lot easier to do one long run of 4-6-8 awg wire into the console and hook into your pre-existing speaker wire connections than to do one short 8 awg run and 4 seperate speaker cable runs and 1 Remote run.... hindsight, under the console would have been better.

Stainless Steel does not mean strong. Check the quality of what you're buying. And get it at home-depot or some other hardware store. Don't buy mounting stuff at West Marine. Oh, and Self-Tapping screws are your friend on a pontoon boat.

HEAT SHRINK EVERYTHING - I had to send my wife to the store for a lighter while I crawled under the boat running the speaker/REM cable to the amp. I don't care if it's probably never going to get wet. It's getting shrunk and taped.

Whatever the MAX power draw should be of the amp is what you should fuse/circuit breaker for. The 8 awg cable has a max capacity of 50. the circuit breaker will trip at 40. The max draw for the amp is 40. Everything is protected.

A cable stripping/crimping tool is money well spent. But spend good money. Don't buy the $15 one. Get the good one.

Feel free to ask questions or give advice. Again, this was my first time. And there is a big difference in the QUALITY and QUANTITY of sound from the speakers.

Stage 3 will be a small bass tube, or a mono amp and sub.

https://www.amazon.com/gp/product/B000N ... UTF8&psc=1 - Amp
https://www.amazon.com/gp/product/B00JJ ... UTF8&psc=1 - Head Unit
https://www.amazon.com/gp/product/B0013 ... UTF8&psc=1 - Speakers

[jrolin1]

I bet the power wires don't interfere.
Here is mine. I used 4 gauge wire to a distribution block, then to the amps. That is three amps and a purple inverter. It powers six speakers (polk) and two 10 inch kicker sealed subs. It is in my never used changing room also.

[kryptonite]

If the amp gets hot enough to melt the battery cables, you have bigger problems. Should not be an issue at all. If you thought it was going to be, just take a piece of flat metal, bend it out away from the amp to create a runner so to speak, then zip tie the cables to that.

[JerEazy]

I bet the power wires don't interfere.
Here is mine. I used 4 gauge wire to a distribution block, then to the amps. That is three amps and a purple inverter. It powers six speakers (polk) and two 10 inch kicker sealed subs. It is in my never used changing room also.

Nice set-up! You're probably right on it not interfering. I'm probably just being over cautious.

[JerEazy]

If the amp gets hot enough to melt the battery cables, you have bigger problems. Should not be an issue at all. If you thought it was going to be, just take a piece of flat metal, bend it out away from the amp to create a runner so to speak, then zip tie the cables to that.

Good point and good idea! Won't be on the water again until the weekend after next. I'll check/test the tempt after it's been on for a while and see if it's a concern.

[Xscash]

The amp will never get hot enough to melt the wires, my concern would be the rca connection and a ground loop. Do you have any interference when running the engine? Boats are notorious for ground loops and they can be eliminated quite easily. A simple ground loop isolator can be installed on the rca wires. Good job with the write up.

[JerEazy]

The amp will never get hot enough to melt the wires, my concern would be the rca connection and a ground loop. Do you have any interference when running the engine? Boats are notorious for ground loops and they can be eliminated quite easily. A simple ground loop isolator can be installed on the rca wires. Good job with the write up.

The RCAs were kept away from any power cables throughout their run. So I'm hoping interference isn't going to be an issue. But I actually haven't had a chance to try it while the boat was running. Only a driveway test. And with this continuous rain here, I'm fingers crossed I can test it in while underway this weekend.

I'll have to google the ground loop isolator. If it's not too bad would some better insulated RCAs help? I'll admit the ones I used were pretty low quality. But I had them at the house and they got the job done.

[mpilot]

The amp will never get hot enough to melt the wires, my concern would be the rca connection and a ground loop. Do you have any interference when running the engine? Boats are notorious for ground loops and they can be eliminated quite easily. A simple ground loop isolator can be installed on the rca wires. Good job with the write up.

The RCAs were kept away from any power cables throughout their run. So I'm hoping interference isn't going to be an issue. But I actually haven't had a chance to try it while the boat was running. Only a driveway test. And with this continuous rain here, I'm fingers crossed I can test it in while underway this weekend.

I'll have to google the ground loop isolator. If it's not too bad would some better insulated RCAs help? I'll admit the ones I used were pretty low quality. But I had them at the house and they got the job done.

They carry the ground loop isolators at best buy but you have to get them from the install bay and they are around 15 bucks. The thing on a boat is ground loops are a lot more common since there is no grounding to the frame like in a car. I actually had one in the stock stereo in our brand new boat when I plugged the phone into the stereo and into the charger at the sabre time so I have one under the dash for the auxiliary input on our boat. I would take the isolator with you just in case and return it if you don't need it. My loop was solved by just plugging it in line and I didn't have to even run it back to the ground. Takes like two seconds to put on.

[JerEazy]

The amp will never get hot enough to melt the wires, my concern would be the rca connection and a ground loop. Do you have any interference when running the engine? Boats are notorious for ground loops and they can be eliminated quite easily. A simple ground loop isolator can be installed on the rca wires. Good job with the write up.

The RCAs were kept away from any power cables throughout their run. So I'm hoping interference isn't going to be an issue. But I actually haven't had a chance to try it while the boat was running. Only a driveway test. And with this continuous rain here, I'm fingers crossed I can test it in while underway this weekend.

I'll have to google the ground loop isolator. If it's not too bad would some better insulated RCAs help? I'll admit the ones I used were pretty low quality. But I had them at the house and they got the job done.

I'll do just that. Thanks for the idea
They carry the ground loop isolators at best buy but you have to get them from the install bay and they are around 15 bucks. The thing on a boat is ground loops are a lot more common since there is no grounding to the frame like in a car. I actually had one in the stock stereo in our brand new boat when I plugged the phone into the stereo and into the charger at the sabre time so I have one under the dash for the auxiliary input on our boat. I would take the isolator with you just in case and return it if you don't need it. My loop was solved by just plugging it in line and I didn't have to even run it back to the ground. Takes like two seconds to put on.

[Xscash]

interference is not from the rca wires, it is caused by the routing of the ground wire and grounding point. rca wires also carry a ground but it originates at the radio and terminates at the amp. these multiple ground points cause a ground loop. you will most likely need one for each set of rca cables.