Amp question

[essexjet]

I have a 1997 essex genesis jetboat. I came from essex with 4 6x9's. I have just completed building a new rear seat with 3 8" sub's built into it. I mounted a fosgate P4004 for the 6x9's and a fosgate 300W mono for the sub's under the passenger side dash. I was told that I have to mount the amp's no more the 18" from the ground or in this case the neg terminal on the battery. Is this wrong or do I need to move the amp to the engine compartment.

[riverbound]

That is the recommendation for a car. A boat is a completely different install. We run a power and ground directly form the batt. or the perko to the amp.

[essexjet]

thanks Bill. I never installed or built a sound system before so I'm new at this. Have you ever built a new seat before. I hope I did it right so it does not come apart with people sitting on it.:confused: I used 1/2 MDF to make to whole thing and then fiberglass resin it. Hope it stays together.

[riverbound]

Yes I have been known to rebuild a seat or two. The only thing I would have done differently was I would have used 3/4 mdf, its a little stronger.

[ROZ]

Originally posted by riverbound
Yes I have been known to rebuild a seat or two. The only thing I would have done differently was I would have used 3/4 mdf, its a little stronger.
NOt just that, but I would have done multiple coats of resin to make sure the MDF is covered. It will soak up water like a sponge from even a pinhole..... :sad:
You made just the enclosure and not the entire seat base out of MDF, right? :confused:

[Mr. Naudio]

Originally posted by essexjet
I was told that I have to mount the amp's no more the 18" from the ground or in this case the neg terminal on the batt
Are sure they where not talking about the power cable to the amps ?
Recomended that this be fused no more than 18"from perco common post or pos batt terminal.

[Havasu Hangin']

MDF? Ouch. Marine ply is the way to fly.
I don't recommend you fuse it any farther that 1.8" from the Perko. ;)
As for the amp...you can mount it alost anywhere. The farther from the battery, the more expensive it is (thicker, longer cable needed). Make sure you through-bolt the amp...screws don't last long in a boat.

[essex_jet1]

You made just the enclosure and not the entire seat base out of MDF, right?
Nope ROZ, I made the entire seat base out of MDF. Should I rebuild it with marine plywood on the bottom and sides and MDF the center and top of the sub boxes?

[ROZ]

the thing is that the base is a structural item that is meant to hold a lot of weight and have to hold up to the elements. In a car it would be alright as long as you had it braced throughout, but I'd seriously consider making the entire assembly out of atleast 3/4 in ply floated with resin or marine ply. You will have to make that base again if you run with it... Save the post MDF base headache and rebiuld the base while you have it out using your old base as a template. If it was just boxes thoroughly resined MDF i'd say you'd be okay, but please rebuild the base. I know it will fail.
If it's any consolation, your design looks good :)
Helpful hint: Dadoing or rouding a channel at the edge of the base at the bottom the thickness of 3 layers of painters tape will give the excess vinyl a good place to be stapled and will leave the bottom of your base completely flat :) .....not that it's crucial, though...