Need Help With Amp Problem

[Who_Dat]

I am having a problem getting my amp to drive my sub. I put a stereo in my boat 2 summers ago. I had never put in a boat stereo and I assumed that it is just like installing it in a car (which I had done). The only difference in the way I installed it was the ground was wired directly to the battery in the boat, while it was to the frame in my autos. So here is the problem.......
First a little extraneous information. I have a 24ft Mariah Shabah cabin cruiser and I replaced the HU w/ a Kenwood, replaced factory 6.5s w/ pioneers, added 2 pioneer 6X9s, and a kicker comp 10. I bought a kenwood 500.4 to push the 6X9s and bridge the other 2 channels to drive the sub. Well, the 6X9s sounded fine, but the sub sounded like crap (it was barely audible from 3 ft away). I did some reading and realized that the voltage drop from my 18ft. power/ground wires might be the problem (although the 6X9s had power to spare). SO, I moved the amp to the back of the boat (about 2-3ft power/ground) and the sub still sounded like crap (although a little less). SO, I figured that the amp was just not the best sub amp (6db bass boost at 90 hz, thats disgusting), and I put in my kicker amp that I had from my car (which I had with the same sub in my car and it sounded awsome). It STILL sounded like crap. The kicker pushed the 6X9s fine, and I put the whole setup back in my car and it still sounds great in there. By the way, my power/ground are 10G, and I know that you will tell me I need bigger, but they are the EXACT same wires that I used in my car and it was fine. I used the exact same remote wire also (although it may be 2-3 ft longer) and I think that they just carry a low current anyway so that shouldn't matter.
So, I have the exact same equipment/setup that works in my car, yet it sucks in my boat. I don't know what else to do. Any help would be appreciated.
Thanks,
Clay

[ROZ]

Is the speaker dvc or svc? what is the ohm rating of the sub? How do you have the subwoofer wired?
10ga is definitely not large enough power or ground. Voltage drops in long wire runs. 8ga. is what I would have run in the car where it's not as much an issue because you're usually listening to the stereo while the car is running thus the alternator is keeping your voltage up above 13.5 volts. Your boat is making out at 12v ouput when your motor is not runing while beach. your amp will shut down due to low voltage at 11v. As you can see, you don't have very much room there so maintaining the least amount of resistance is key. Your power and ground wire should be changed to atleast a 8ga wire..
Where is your subwoofer located, and is it in the proper enclosure?
Also, your 500.4 kenwood is likely rated at 14.4 volts at 2ohms. 12 volts at 4ohms will be considerable less power.
Remeber that the system in your car will be louder because among other variables, it's inside the vehicle. The boat is open air, so it will take more to get the same output.

[Who_Dat]

Is the speaker dvc or svc?
dont know. Its a kicker comp 10 from about 9-10 yrs ago
what is the ohm rating of the sub?
4ohm
How do you have the subwoofer wired?
???? its only one sub right now (no series/parallel, etc.); bridged at amp, +/- at speaker
10ga is definitely not large enough power or ground. Voltage drops in long wire runs.
I knew you would say that, however, it is the EXACT wire that I pulled out of my car and placed into my boat. It should work the exact same. The length is only 2-3 ft so should not drop voltage.
listening to the stereo while the car is running thus the alternator is keeping your voltage up above 13.5 volts. Your boat is making out at 12v ouput when your motor is not runing while beach. your amp will shut down due to low voltage at 11v.
My car sounded the same whether it was on, or off for an hour. It sounds the same whether my boat is on (~14V) or off, it (the sub, not the rest of the system) is barely audible. The amp is not shutting down, it is fine, i.e. still pushing the 6X9s when I had the kenwood hooked to it.
Where is your subwoofer located, and is it in the proper enclosure?
It is in the rear of the boat, in a storage compartment. It is in the same exact enclosure that it was in in my car.
Also, your 500.4 kenwood is likely rated at 14.4 volts at 2ohms. 12 volts at 4ohms will be considerable less power.
True. Thats why I put in the kicker amp (it puts out more power than the sub can handle). But, the kenwood has plenty of power to push the 6X9s because I have to keep it turned down.
Remeber that the system in your car will be louder.
This is also true. But what I am saying, is that the amp is not driving the sub "right". I have the luxury of knowing the system because I have had it in my car and I know what it should sound like. Something is wrong. I dont mean that I was hitting a 140 and now I am hitting a 130, I mean you cant even tell it is there. It is barely audible when you are 2ft away, aka not functioning properly. The equipment is fine, because it worked in my car, then it didn't in my boat, then I moved it back to my car and it was fine again, all with the exact same wiring and setup.
I dont know what else to tell you. I would spend the money on upgrading the wire, but like I said, it is the exact same as in my car so I know it should work (also I have rewired the whole thing 3 times trying to get it to work better and I really dont want to do it and then it still do the same thing). Do you have any other questions or suggestions? Thanks. Clay

[ROZ]

Single or dual voice coils will make a difference in wiring. Single VC 4 ohm will be just that, 4ohm. Dual VC 4 ohm will run 1 or 4 ohms with one driver. THis is why I asked how it was wired. Sorry for any confusion.
I was referring to the 18ft run regarding the ga of wire... 3 feet shouldn't make a real difference. afterall, you're now running2 amps :220v: One fully charged battery?
The same exact enclosure you have in your car may not actually work best in your boat. Is it sealed, vented, bandpass, or downfiring created for the paramiters of the driver or was it made including the resonant frequency of the car?
All things being equal, the sub is in a closed storage compartment instead of the interior of a car. If you're hooking up everything the exact same way with the exact same gear, the amp is driving the sub the same whether it's in your car or boat. The circumstance is the difference.
Does it sound different when the compartment is open?
What is the result when the subwoofer is run outside the compartment?
Which Kicker 2 channel amp are you using?

[Who_Dat]

I'm not sure what you would call the enclosure. It is a non-traditional bandpass I guess, because the port is coming out of a chamber that is in front of the speaker which is itself (the speaker) in a sealed enclosure (if that makes sense). This really isnt the issue. What I dont think you are understanding is that is not working correctly, period. I understand that the acoustics will be different, and I was expecting that. For instance, if you stick your hand in front of the port, you can barely, I mean barely feel the air. Whereas in my car, it was like a blow dryer. It performs the same no matter if the compartment is closed, open or outside. The amp is a TI-100 I think. It is about as old as the sub. It is plenty of power for the sub.

[ROZ]

What I understand is that you have low output when it's in the boat and great output what it's in the car? Or it has very low output period? Which one is it?
BTW, your description fits a 4th order bandpass... Not really condusive for boats. They normally work well with the highllighting the bass boost from the interior of a car...

[PHX ATC]

ROZ understands...believe me, he understands.
This guy works magical miracles with stereo, electricity, 12V, 6V, 9V, whatever, he can make it work. 4th order bandpass, 7th day Adventist, he knows all about it.
ROZ, you da bomb! :mix:

[riverbound]

Roz is on the right track. I would put the sub in a sealed enclosure adn you should notice a difference. I have never had good luck with bandpass boxes and boats. Also you will lose a lot of sound in a boat because it is an open environment that you are trying to fill with sound. Where as a car is enclosed and doesnt need as much to make it sound good.

[BadBahner]

The main difference that I am seeing is the ground. Is it ok to run the ground directly to the neg terminal on the battery? Or should it go to the ground on the block?
Eric

[ROZ]

The main difference that I am seeing is the ground. Is it ok to run the ground directly to the neg terminal on the battery? Or should it go to the ground on the block?
Eric just the battery will do. I've seen people do both. The JL 5 channel amp in my 4runner is grounded at the chassis at the rear of the car, but I 'll be running an extra 4ga ground to the battery...