stereo system problems.. i need help

Lyte Skin · Outlaw Joined: 15 Feb 2003 Posts: 210 City: San Angelo, TX

i was putting a stereo system in my boat today and i ran into a couple problems. I hooked everything up and i am getting some nasty feedback through the sub. I am also getting some humming from the tower speakers too. I have a fosgate punch 600 5 channel amp. I have everything mounted there but i am just getting a lot of humming. If you crank it up you can hear the bass line throught the sub but a lot of humming. the tower speakers hum a little bit but you can still hear them fine. i am just gonna amplify the tower speakers and the sub. the others will run off the deck. I don't have the speakers inside the boat hooked up because they are about to get replaced. I looked and looked for the problem but i have no idea. I know the basics of stereo junk but i am no expert. Any help would be appreciated.
Thanks

Geoff Standish · Addict Joined: 13 Jan 2003 Posts: 843 City: Calgary

I would check to make sure that your speaker and RCA wires aren't running along side any amp power wires. This can cause interference.

Is this happening with the engine on or off? That could be a factor as you could be getting interference from the engine....

Good luck!

Magic · Outlaw Joined: 27 Jan 2003 Posts: 240 City: Seattle

Sounds like (ya, bad pun...) you have a ground loop problem.

Four things come to mind.
- Follow Geoff's advise and get any RCAs away from power lines and ignition sources. All ways a good thing to do with installs.
- Try a different amp. Some work better in boats than others.
- Go to Radio Shack and get some RCA ground loop isolators (PAC and other companies make these too)
- How is you ground wire from the amp connected? Did you go directly to the battery? Did you use good RCAs?

I had a like problem in my boat. I was using a top of line Kenwood amp to run my speakers and sub. Thing just picked up the boat's system. It buzzed, poped, whined... I replaced that amp with two Xtants (one for the tower and boat speakers and one for the subs). The Xtant amps in my boat do not pick up the boat's system noise at all.

Interesting enough, I just added an other amp for one of the subs. Its a huge Kenwood Class D sub amp, its super quite, no noise. Go figure.

ckligor · Soul Rider Joined: 18 Feb 2003 Posts: 454 City: A-town

That is exactly the problem.. Ground Loop, it's a more dominate problem in Cars then anything.. I would go get isolators for the RCA connects and one for the power line.. I assume you ran a dedicated line from your Battery terminal to your amp and didn't pull power off your breaker box, right? You can also lower the ground loop by not running a ground wire more then 2 feet.. Move your amp closer to the Battery or at least closer to a ground source.. I put 2 - 12" infinitys in mine and can tell you it's better to run a lot of speaker wire then a lot of power wire..

Lyte Skin · Outlaw Joined: 15 Feb 2003 Posts: 210 City: San Angelo, TX

I think i do have the rca's to close to the power wire.
Also i have the amp in the bow of the boat and a ground wire running all the way from the battery. there is nothing to ground the wire to in the bow of the boat because its closed and its all fiberglass.
I will try out what you guys said and i will let you know.

Lyte Skin · Outlaw Joined: 15 Feb 2003 Posts: 210 City: San Angelo, TX

do i need to have the power wire and ground not close to each other?
because i zip tied them together to hide them up underneath the side of the interior.
i am thinking it might be the rca to close to the power. that is my guess from what you guys said.

ckligor · Soul Rider Joined: 18 Feb 2003 Posts: 454 City: A-town

the power and Ground together don't make any difference... You just don't want the RCA's near them if you can help it.. I'm telling you that you might have to move the Apm close to the/a ground so you can use a short ground wire.. You can try the isolator first but you are going to need to get a RCA isolator and put it in line as close to the amp as you can.. I would plug it in to your amp and then plug the RCA's in to it.. Don't put it by your head unit..

porter · Outlaw Joined: 23 Jan 2003 Posts: 109 City: Sammamish

I used to have that amp in my boat. I don't know what your humming problem is, but I can tell you that amp is 2 ohm stable. This means you could run your sub and eight more speakers off that amp (two 4-ohm speakers of each of four channels run in parallel). I would absolutely run all your speakers off that amp instead of using deck power. Deck power is crap compared to the power you can get out of that amp. As long as you don't have more than eight speakers and a sub that amp should run your entire system.

Lyte Skin · Outlaw Joined: 15 Feb 2003 Posts: 210 City: San Angelo, TX

porter, i was thinkin of doin that and i guess i will now.

it was a rca problem. i don't have any hum in the tower speakers but the subs still hum i am going to the speaker shop tomorrow for the isolators ckligor is talking about and try that. it should work then.
thanks guys

ckligor · Soul Rider Joined: 18 Feb 2003 Posts: 454 City: A-town

Lyte,
If you are going to hook up more then one sub to each line remember to step down the ohm load you are going to need to hook thoes up in paralell.. Please remember that each time you put a 4 ohm speaker on the chain you cut the amp ohm load in half. two speakers=2 ohm 4 speakers = 1 ohm 8=1/2 ohm.. Do not bridge your amp and cut the ohm load below 2 ohms. your amp will become unstable and get so hot it can catch on fire.. Remember your amp will run hotter the more load you put on it.. If you decide to cut ohm load put it in a well ventalated area..

ckligor · Soul Rider Joined: 18 Feb 2003 Posts: 454 City: A-town

I Hope I Explained that OK.. Look at this image it will show you how to do it.. I gave you the directions for keeping the ohm load at 4 ohms.. Look at this.. Sorry!!! It's still early