need help with Amp wiring

D

djboots

New Member
Apr 29, 2009
145
Chesterfield, MI
Boat Info
2001 340 SeaRay Sundancer
Engines
8.1 Mercs
I'm installing 2 amps, one for sub and one for cockpit speakers. I ran the the 4 guge power wire already but i had an idea with the ground that i'm not sure if it would work.

I'm going to put the amps in the closet next to the aft cabin. In that closet there is the power wires running to my windlass, which are also 4 guage. I was thinking of cutting the ground wire and linking it into a amp capacitor. Then i would be able to run the ground for the amps right from the capacitor. Is it a good idea to cut in to that ground and have it be shared with the windlass and the amps??? I'm going to have a capacitor either way before the amps so i was thinking that would keep a shorter ground wire and i would not have to run a seperate one ran so far back to the battery.
 
well i think i found the answer. looks like i should have just tapped into the windlass power line and ground line to begin with. that way i would not had to take an hour to run that dam fish tape back to the bilge. I talked to my local car audio place and the said the do it all the time. As long as the wires are thick enough should be good. just to make sure i use all the right connectors to make a clean connection i should be good. The capcitor is just like putting a mini battery in the power lines.

any input??
 
I'm sure some installers do tap into existing wiring, but everything I read during my recent JL Audio amp install said to run a dedicated ground cable from the "main" ground bus in ER and to provide circuit protection (fuse/breaker) within 18" from the battery on the power cable.

If you are running the power cable anyway, why not run the ground cable with it?

Not familiar with caps on marine installs.
 
well the reason i was leary about running the ground with the powerline is that I did dont want the ground to be so long. I have always understood the the ground should be as short as possible.
 
djboots,

Both your audio power and ground should run directly into the engine compartment and tie into the house bank.

By tying into the windlass ground you've saved wire but you haven't lowered the resistance. You've also put more resistance between your source unit ground and amplifier ground. You're grounded farther away from the engine blocks which is the highest ground mass on the boat.

What happens when the windlass is operational at the same time as the stereo? Any noise?

David
Earmark Marine
 
Agree with the rest of the crowd, Ground is as important as power. Clean power and ground, clean sound. Fishing two wires is as easy as fishing one.

How does it sound. I just added a infinity 6100m and speakers to my 230 on the wakeboard tower, sounds awsome.
 
From what I had researched when I did my installation, caps are more about bling than any actual improvement in sound.

What gauge do your amps require? If it is 4 gauge and you are running 2 amps, you want to run something bigger to a block and then go 4 gauge to the amps.

BTW, I agree with running dedicated lines for your amps.
 
teekster said:
From what I had researched when I did my installation, caps are more about bling than any actual improvement in sound.
Click to expand...

I tend to agree - if you have adequate wiring and battery(ies) then you rarely will need the additional surge power provided by a cap. Run your wiring as already suggested and leave out the cap for now - it's just one more thing to worry about in a marine environment. Good luck.
 
I did what you are doing, but... The ground wire is fine to share with the windlass, but not the power wire. The grounds are all common on your boat, but if you use the power to the windlass there are three problems; 1.The windlass load will make noise in your stereo when used, 2.the circuit breaker is not big ebough to support stereo and windlass at same time, 3. windlass is powered by a continuous duty solenoid that pulls at least 3 amps, which is power you do not want to throw away.

Also, a typical 1 farad cap used in audio system is a waste of money. They are good for nothing but looks (if you even like the way they look). Totally useless. Not my opinion, pure fact. Don't waste your money as 1 farad isn't enough to do anything at all at 12 volts for a stereo system.

I will try to remember to take pictures when I get home, I mounted 2 1000 watt amps in the same place you are talking about, and only new wire I ran was 4 awg power wire.
 
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chris41483 said:
I did what you are doing, but... The ground wire is fine to share with the windlass, but not the power wire. The grounds are all common on your boat, but if you use the power to the windlass there are three problems; 1.The windlass load will make noise in your stereo when used, 2.the circuit breaker is not big ebough to support stereo and windlass at same time, 3. windlass is powered by a continuous duty solenoid that pulls at least 3 amps, which is power you do not want to throw away.

Also, a typical 1 farad cap used in audio system is a waste of money. They are good for nothing but looks (if you even like the way they look). Totally useless. Not my opinion, pure fact. Don't waste your money as 1 farad isn't enough to do anything at all at 12 volts for a stereo system.

I will try to remember to take pictures when I get home, I mounted 2 1000 watt amps in the same place you are talking about, and only new wire I ran was 4 awg power wire.
Click to expand...

I would love to see the pics!!

Thanks for everyones input
 
To those that said the ground wire is as important as the power lead you are only partly correct. In consumer audio with single ended (as opposed to balanced) audio input signals the ground is more important than the power lead. The power amp will amplify the audio input signal with respect to its ground. If there is a difference in the ground level between the audio source and the power amp noise will result. The difference in ground level will occur when there is a large current flowing in the windlass ground wire you are tapping into. If you are only going to run one wire you would be better off to tap into the power wire and run the ground as a separate wire.
 
You could always install a ground loop isolator if necessary. The 1.0 Farad cap mentioned earlier would also take care of this noise, this is about the only thing it would be good for. I do not have noise in my system whatsoever even while using the windlass, and I am using the ground as mentioned earlier without the cao or ground loop isolator.

The power wire is not a good idea in the application, as mentioned before, because of the solenoid, and also the small breaker.

I had a friend years ago that didn't understand electronics or wiring whatsoever. He thought that the power flowed from pos. to ground (wrong), and that the ground could be smaller than the pos. because whatever device was connected USED the power.

There is an equal amount of current flowing through both wires. neg to positive. this is always true with direct current.

I don't know if you have decided how to connect to the ground wire yet, but here is how I did it; I used a split bolt, I soldered the new 4 awg wire to the head of the bolt, cut insulation from the existing windlass ground, and put the split bold over it. Then put lots of dielectric grease on it before reinstalling the top closet panel. turned out quite well.

I am sorry I forgot to bring my camera disk, I will post a picture when I get home.
 
chris41483 said:
I had a friend years ago that didn't understand electronics or wiring whatsoever. He thought that the power flowed from pos. to ground (wrong), and that the ground could be smaller than the pos. because whatever device was connected USED the power.

There is an equal amount of current flowing through both wires. neg to positive. this is always true with direct current.
Click to expand...

First there is no such thing as power flow. It is current flow and the direction is from the positive to negative. Electron flow is from negative to positive. The same amount of current will flow in both the positive wire as the negative wire, (either AC or DC) assuming there is no other current path.

In consumer audio the signal is referenced to the negative (or ground) terminal so it is more important to keep the noise off of the ground connection than the power connection.
 
Symantecs.

I would say tapping the pos. cable is a bead idea because of the reasons I mentioned earlier. If there is someone who is able to scare you into running two cables, so be it. It's just another few bucks worth of 4 awg. However, just to let you know, I have tapped into the windlass ground with mine, run a new power wire, and have no cap or traditional ground loop isolator, and mine sounds great and has no interference.
 
djboots said:
chris41483 said:
"I used a split bolt" quote]

I looked up what one looks like...but where do you buy it??
Click to expand...

I bought two at Ace Hardware yesterday to help me install my third amp. They are copper, came in pairs, and were about $6.50 for the pair. They easily hold 4 ga wire at that price. The bigger ones went up to about $11.
Click to expand...
 
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