MILD THUNDER

iTrader: (3)

I had problems this season with my stereo system. I was out one day running the boat hard. That night I noticed the stereo did not work. Every thing powered up but no sound. Turned out all four speakers shorted out. I replaced them and added some 12" subs. I just figured I had the volume up too high. Now I get whine from speakers when engine is running an both of my subs blew when I turned the amps on. I get a real bad thump when the amps power up and when I raise the trim my woofers bounce. I have tried evrything to fix this. New amp wires, different grounds, etc. I am frustrated and its ruining my speakers! I run two amps and they both do it.

mcollinstn

cheap amps? They may have been damaged by under Ohming them or overheating them. Now they may be pouring too much current to your speakers. The "new" whine suggests some blown components in the amp's power supply.

Run amp hot wires directly to the batts. Run isolated grounds directly fm batts. Make sure you wire the main spkrs as instructed. 4 four ohm speakers result in 2 two ohm loads. Less expensive amps cannot live into 2 ohms. Wire them series to present an 8 ohm load.

find a local guy who knows his stuff.

deboatmon

Mcollinstn is headed in the right direction. If your speakers are moving in and out slowly it's possible that your amps are outputting DC. That represents a major malfunction. Take care when calculating the impedance load on each amp also. You may get better results when running amps in bridge mode and at higher rather than lower impedances. More power is usually the answer along with better supply voltage and current. When amps run into distortion the voice coils over heat then lose their shape inside the magnet and start rubbing. Then they heat up more and it's a catch 22. The more they heat up, the more they distort in shape. The more they distort in shape the more they heat up. Eventually the voice coil opens. This is a common result from too little power.

Wire extra heavy direct from battery banks to all amps and fuse all supplies properly. Run higher impedance loads. Insure that the amps can get some amount of cooling by either convection or forced air. Using an electronic crossover will increase system efficiency by 3 db. That will effectively double the power. Wiring anything out of phase will decrease efficiency greatly and can be a cause of overheating as you will turn up the volume to compensate for the decreased output thus using more electrical energy and eventually overheating.

To make lots of reliable, intelligible sound for a big, loud boat requires a lot more work than for your mothers pontoon boat.

Good luck and good tunes.

Tinkerer

Also make sure that your signal input cables are tightly connected and DRY.
Are your input cables away from the power and ground cables?

I had an amp do what yours are doing and it was the input cables.

MILD THUNDER

iTrader: (3)

I am running 4 gauge power wire straight to battery. All speakers are 4 ohm, running 4 on a 4 channel lightning amp. Subs are wired to 2 ohm off a mono profile sub amp. I ran the subs in my car with the same amp for a year and it worked ok. And it worked ok in the boat for a month after I hooked them up. I just dont understand why it would happen all of a sudden. Especially both amps. The head unit has dual rca outputs, running them into the 4 ch and then a rca from the 4ch output to the sub amp. They speakers pop even when I switch the head unit from cd to radio. The worst popping is when powering off. Maybe the amps got moisture buildup from being in the boat and it shorted them??? Maybe I should hook up a muti meter to the speaker terminals and see what it reads when I power up or off? I should not see 12 volts correct?

Audiofn

I am thinking head unit problem......OR a bad RCA going from your head unit to the amp. Disconect the RCA's from the head unit AND amp. Then turn the system on. If you still get a thump then find out what one is making the thump (subs or mids/highs). If it turns on now with no thump then you can start to look at the RCA's or head unit. Take a spare RCA or buy a cheepo and just run it from the head unit to the amp. I think you will find this to solve the problem but diagnosing from a far can be hard as I am relying on your discription. What I see a lot of times is that people do not get their RCA and power wires held down real well. They move around and then eventually break or short out. At any rate give that a try and let us know what the result is.

Jon

Jon

fund razor

Suspected problem with head unit.

Originally I suspected amp(s) because dead shorts and excessive DC output do the "blow every speaker" trick.

Speakers popping when you switch sources on the head unit is a big clue.

Too bad you can't temp in a different head unit/ source to the amps before you disturb the rest of the install.

You will see DC on the outputs of the power amps, the question is how much.

mcollinstn

4 gauge power wire. Sounds good.
What size ground you running? Are you running it straight to the batts?
Is the head unit running off the same DC circuit or another one?