Ground issue and probably need a cap...?

[TravisFling]

Hello all!!!

1989 Ski Nautique 2001

I got the stereo done, with 260 watt amp pushing the tops, went with 4 Polk DB651's, two in the front gunnels, two in back that I built custom boxes for that fit under the gunnel walls. Put a downward firing 10" infinity sub up front pushed by a 520rms amp, mounted on the box. Elclipse cd3000 HU. Sounds great, except for two issues.

1. I'm picking up a lot of engine noise, which I assume is from a bad ground, but where to ground on a fiberglass boat? Right now it's grounded on the battery. Should I ground to the lift ring assembly under the bow? Put in a line noise filter? Any other ideas?

2. When the bass hits it cuts out pretty frequently, but then comes right back on. I turned it down which somewhat alleviated the problem, but that's not a good solution, as I have to turn the bass down... I assume the amp is drawing too much power, and is cutting out. Does that mean I need to put a capacitor in there to store some power, and alleviate the load it's pulling? If so, what type, and where would it go in the schematic? I believe in my truck I put my cap between the battery and amp, but just making sure, if that's the solution, that I've got it right.

Thanks in advance!!!

Travis

[JUST-IN-TIME]

RE: Ground issue and probably need a cap...?

run the grounds off the battery or the grounding block

[TravisFling]

grounds are currently run to the battery, but I need to double check where the HU is grounded, and then ground them in the same place. Thanks, though!

I'm going to try to un-bridge the amp and see if that helps..

[AuMDLST]

Lifting ring is not "grounded" - the negative terminal of the bettery is the "ground" you are looking for.
Is the sub amp cutting off while the boat is running or with the engine off? Most amps are rated using a 14.4 volt rating and when not running you are going to have less than 12 volts under a sub draw and can trigger the internal amp safety cutoff.
Your ground wire should be the same size as the 12v pos wire
How is the sub wired to the amp? Exact amp and sub model would help as well

[TravisFling]

Problem is actually when the boat is running. Weird, but true. I think it's definately the safety on the amp, but after talking to some others it might be to low ohms for the amp to handle. The power and ground are both 8 guage, on a three foot run. Pioneer amp 760w peak, 520 watts rms bridged. The speaker is a 10" Infinity DVC, and it's run in series. Maybe I should switch that to parallel? I'll try to ground the HU to the battery, which I believe it's not, and see what that does and unbridge the amp, and see what that does. hopefully that works out for starters.

Travis

[Andrew]

wiring the sub in parallel will reduce the resistance and put more strain on the amp. what is the minimum resistance that the amp is able to handle and what is the resistance of each voice coil on the sub? if each voice coil is 2ohms and your amps minimum rating is at 2ohms, then wiring in parallel is a sure way to burn the amp up. if your not sure on what to look for, post the exact model numbers of the amp and sub and i'll look up the specs.

i'm gonna bet that you've got you speaker wires too close to your power wires and that will be where you get interference. make sure that you keep the speaker wires as far away from ALL power wires (regardless of what they are connected to) and you shouldn't have any more interference. a direct connection from the amp to the battery is ideal, so there is no reason to worry with grounding it somewhere else.

are you running anymore amps, lights, or any other accessories that draw a lot of power? if so, then u'll definitely want to upgrade to a high output alternator. if the amp is the only extra draw, then you MAY be able to get by with a capacitor, but i don't ever recommend them. a bigger alternator and dual batteries are a much better solution

[TravisFling]

Hey Andrew,

I always love it when you post, so I get to see that Avatar again... and again... Makes we want to head back down to bama! (I was just down in Gulf Shores in August for 10 days). I think the wiring is pretty good, and I think the problem is that the HU is grounded off the distribution block and not the battery, and having them grounded in different spots is creating the loop. I meant to do all that last night, but we had a cold snap (35) so I was staining rough cut cedar instead. Thanks for the reply's and I'll post as soon as I do some research. The sub is a pretty good one, but the amp isn't, so I'll assume that's my weakest link and start from there. It's so much easier to build a system when you're working with good components, but unfortunately, the boat got the leftover's this year...

Andrew - Where would you put a second battery in a 2001, and also how would you link the batteries together? With a switch of sorts?

[Andrew]

i put my batteries under the bow. some guys have a cooler and battery compartment that can each hold a battery, but most only have one. as for linking, you can just wire them together +to+ and -to-. if you spend a good bit of time listening to the stereo when the engine isn't running though, i'd isolate one battery to starting and one to the stereo when the ignition is off. you can do this with a high amperage relay, an isolator, or a high dollar switching module like the hellwig......... it all depends on budget and your desire to monitor what is going on.

[Andrew]

ignore the reference to hellwig (that's a suspension company.....) i meant to say hellroaring

[TravisFling]

Andrew,

Just to make sure I'm correct on this one... I can get a Marine battery and run it with the other in series? Should I get a golf cart battery, or deep cell marine, or...? Any thoughts on that? we would probably send 1/2 hour to an hour at most listening to the radio and mostly we'd be driving around the lake, maybe a little bit of swimming, but mostly riding. (if we was gonna just hang-ten, i'd have bought a pontoon...

I have access to several types of batteries that I listed above, so just wondering which would be the best one to get.

[Andrew]

i wouldn't recommend mixing batteries.... if ur gonna run dual batteries, keep them the same.
6v golf cart batteries will need to be run in series, while 12v batteries will need to be wired in a parallel circuit.
just keep in mind that a series cicuit will double the output voltage while a parallel circuit will remain the same

[gride300]

using a cap in a boat is kind of useless since you cut the engine off frequently. i had one in my old x2 but took it out. make sure you fuse your amps and start with the gain all the way down and turn it up slowly, then turn back down once you hit distortion

[TravisFling]

Thanks for the advice. The only problem I'm having right now is the ground issue. I've got everything else figured out. Just unbridged the amp and turned it up, ran the speaker a little different and she pounds even harder, and doesn't cut out. I'm working on the ground issue, but I need to get a bucket and hose set up, or drag it down to the launch, a whole 1/4 mile away... I know, I know.. poor me...

[gride300]

good luck. stereo's are fun, but cumbersome.

[gride300]

i had all the speakers replaced in my mc recently and they didnt fuse the amps(potential fire) and had them wired all messed up. that was the final mistake that led me to get a 210