PDA

View Full Version : Need Help With Amp Problem



Who_Dat
09-09-2004, 06:51 AM
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
09-09-2004, 10:13 AM
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
09-09-2004, 11:53 AM
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
09-09-2004, 01:15 PM
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
09-09-2004, 01:57 PM
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
09-09-2004, 02:04 PM
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
09-09-2004, 03:51 PM
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
09-09-2004, 08:04 PM
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
09-09-2004, 10:35 PM
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
09-09-2004, 11:52 PM
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...

Who_Dat
09-10-2004, 06:54 AM
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?
Yes, low in the boat, high in the car. If by period, you mean length of time that it is able to put out sound, then it is not the period.
As far as the enclosure type, I will address that when it starts working right. But, "good sound" is not the issue here, it is not that it just doesn't sound good, it doesn't sound at all. Like I said before, when I am 1ft. away or when I put my hand in front of the port, its just not the same. So, changing enclosure, boat size/acoustics, etc. are not an issue until I can get it driving like it should. Oh by the way, I also had a sealed pioneer 10 in a truck box that I stuck in there to see if it would work, and it did the same thing. It sounded good when in my car, crap in the boat.

ROZ
09-10-2004, 08:30 AM
Are you using the same deck in the boat as in the car? MAybe the headunit has a blown rca output...

Who_Dat
09-10-2004, 11:45 AM
If that were the case, wouldn't there be a problem with the amp when pushing the signal to the 6X9s. It only has a problem when pushing the sub. The signal and amp performance is perfect on those.

ROZ
09-10-2004, 12:50 PM
I guess it really depends on how many 2 channel preouts you have. I have an Alpine deck here beside my desk that has a preout sub channel that's not working...
How many preouts?

Who_Dat
09-10-2004, 01:15 PM
I have 2, it is running off of the rear preout. But, I am only running 1 RCA back to the amp/s. So, it is the exact same wire that works fine for the 6X9s.

1stepcloser
09-10-2004, 02:53 PM
To me it sounds like there simply isnt enough power.
That Kenwood is likely producing maybe 150 watts to that sub. While that may be sufficient in an enclosed area like a car, in the open environment of a boat, it simply is not enough. Particularly in a 4th order enclosure. If I remember correctly this type of enclosure will enhance the very low freq. (sub-bass) tones, which generally cant be heard at low power levels in an open environment such as a boat.
I had the same issue....
In my truck a PPI 150 watt 2 channel bridged to two 10" RF SVC's, sounds great....strong bass.
The same amp was in the boat with the same subs and no output.
The subs would move, but you could not hear any noise. :confused: I tried different enclosures, to no avail.
I understand that your point is that you believe that the sub is not functioning properly, but the fact that in the car it provides good sound should prove that the sub is indeed functioning correctly.
If I'm reading your post correctly, and you are simply removing the components from the car (where they sound great) and installing them in the boat (where they have no sound) The only thing that has changed between the two installations is the acoustic environment.
You need more power, Mr. Scott.

riverbound
09-10-2004, 10:05 PM
Maybe the deck has a built in crossover and it is set to high pass? :idea:

Who_Dat
09-11-2004, 06:14 AM
1stepcloser:
That Kenwood is likely producing maybe 150 watts to that sub. While that may be sufficient in an enclosed area like a car, in the open environment of a boat, it simply is not enough. Particularly in a 4th order enclosure. If I remember correctly this type of enclosure will enhance the very low freq. (sub-bass) tones, which generally cant be heard at low power levels in an open environment such as a boat.
I have never had the Kenwood amp in my car. When I speak of the car setup, it is just the kicker amp. I know that the kenwood is not powerful enough, but I have been mainly talking about the kicker amp which has plenty of power. The kenwood was just to show that it is happening in 2 different situations. Also, I mentioned that I had a different sub in there to try which was in a sealed enclosure.
I understand that your point is that you believe that the sub is not functioning properly, but the fact that in the car it provides good sound should prove that the sub is indeed functioning correctly.
As I also said earlier, without even mentioning sound, if you put your hand 1 inch away from the port, you can feel just enough to tell that it is on. This should be the same in both settings. The AMOUNT (quantitative) of air being pushed out would be the exact same, however the SOUND (qualitative) it made would/could be different. I hesitate to mention this, because most people are missing the point entirely, but I don't think that the sound would be that much different. The space that I have my sub sitting in is roughly the size of my trunk and The "open" space has very high side walls, and when in my car, it sounded a lot better with the windows/sunroof open. However, this is not what my question is about, because like I said, there is a POWER issue arriving from the same equipment used in two different settings, not SOUND.
riverbound:
Maybe the deck has a built in crossover and it is set to high pass?
Good idea, but it is a lower end deck ~$130 and it doesn't have one. Also, the sub 200hz tones are going to the 6X9s, and also the tones are actually at the sub, however only enough just to say they are getting there. If it were crossed over, then they wouldn't even show up.
thanks for the ideas. Anymore? keep 'em coming because I have messed with this thing for 3 summers now, and I am getting a little perturbed.

PHX ATC
09-11-2004, 06:45 AM
Your boat is posessed with a stereo poltergeist.
Sell it and get another one. :D

1stepcloser
09-11-2004, 08:08 AM
My apologies, I inferred that you were removing the system from your car and installing it in your boat.
I have the exact same equipment/setup that works in my car, yet it sucks in my boat.
I have the luxury of knowing the system because I have had it in my car. 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.
Apparently you have similar components in the boat.
I've never had the Kenwood amp in my car. I is just the kicker amp. Also, I mentioned that I had a different sub in there to try which was in a sealed enclosure.
I'm confused now.
The space that I have my sub sitting in is roughly the size of my trunk and The "open" space has very high side walls.
Is the sub mounted free air?
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.
So.... if the componenets are different, save for the amp, the comparisons are moot.
Perhaps the 10 year old sub is the problem. :cool:

Who_Dat
09-11-2004, 10:23 AM
Ok, you are confused. It is all in the previous replies, however they are long and it is probably hard to keep it all straight. I had the system in my car (kicker amp/kicker sub). I put in a new kenwood amp and an old pioneer sub which I had in my old truck into my boat. I was having the affore mentioned problems. So I put the kicker amp to the pioneer sub to see if it was the amp not having enough power. It did the same thing. Then I put the pioneer sub in my car with the kicker amp to see if it was my sub. It worked like a charm. When I got a new car this summer, I put the kicker sub in on the kenwood amp to see if it would work. It did the same as the pioneer. So, I then put the kicker amp in the boat with the kicker sub. So now I have the kicker amp/kicker sub combo in the boat which is what I had in my car. The kenwood (4 channel) is still there, it is pushing the 6X9s, and will be pushing the 6.5s when I get this sub thing straightened out. So we can address the problem with the kicker amp/sub, the other combinations were just there to show that I have tried to figure out the problem by trying different components and the exact same thing is happening no matter what I put in there. I have also rewired it 3 times using similar configurations.
The sub is in a 4th order bandpass. When I say "open" space, I mean the boat area with the seats, steering wheel, etc. The sub is behind the back seat, in a storage compartment next to the engine.
All of the equipment is in perfect working order.
I don't think it is possessed, although I haven't ruled out voodoo. It probably is just ornery. :messedup:

Who_Dat
09-13-2004, 08:51 AM
Has everyone given up? No more ideas? :confused:

ROZ
09-13-2004, 09:46 AM
Where are you located?

Who_Dat
09-13-2004, 09:56 AM
The exciting metropolis of Little Rock, AR. ;)

Who_Dat
09-15-2004, 01:16 PM
I guess the experts can't solve it.

PHX ATC
09-15-2004, 04:27 PM
Put it back in your car/truck and order up an entire new ensemble for the boat.
Problem solved. :D

ROZ
09-15-2004, 11:06 PM
I guess the experts can't solve it.
We could if we could get our hands on it...
You go from one 2ch preout from the deck to 2 amps. Are you using a Y connector or crossover to split the signal. Is your battery(s) fully charged? Perhaps the means you've split the signal has gone bad? Have you tested by running the rca ONLY into the sub amp?
Ditch the bandpass, it will never work as designed in a boat aplication. It works in conjunction with the interior of your car. A good 250 watts running a sealed sub(or 2 , right Mr. M ;) ) vented into the cockpit should do the job...
If you wish to call to further discuss the subject..... Maybe a clue that you're not typing that we may catch over the phone. :)

Who_Dat
09-17-2004, 07:36 AM
Yes I have run the RCA directly to the amp. I have tried every combination possible to isolate the problem. IF it ever works correctly, I will run the RCA's to the amps in a series: RCA from HU to kicker amp, then from there to the Kenwood.
I would like to talk to you, how do I get your number.