I have a Rockford Fosgate Punch 4 200w Channel Amp mounted under the front passenger's seat and lately it has been over heating to the point of fading off . When it is this hot I can't touch it for more than a second... it is that hot. I haven't done anything to is since I had it installed 2 years ago except disconnect the subwoofer wires and reconnect them (maybe have them reversed polarity?) and my sub coil is blown (kinda). Would these things be related?

These conditions have existed for several months but it is just now starting to get really hot...

Thanks for your help!

-N8

 

Hi Nate, if your coil is blown, then the impedance is screwed up and probably cut in half and confusing the amp.
A Rockford amp can run at 2 ohms, as I use to run my 200a4 like that for an old subwoofer.
But they prefer to run at 4 ohms.

But yours may be running at 1 ohm now, or at 2 ohms due to the voice coil being bad.
Rockford's can not run at that low of an impedance.

That would be where your heat is coming from I would imagine.
Eventually it's going to fry something.

Can you switch out subs with a loaner to test this theory?
I bet that is the problem.
Others with a better understanding of ohms and electronics will surely have a better answer than mine, but that is what I suspect.

 

I think Corey's on to something there. I used to have a Fosgate years ago which powered my 6x9's (not as powerful as the ones you guys have) and I do recall something about RF and ohms. If the ohms aren't high enough it could easily overheat w/too much power going through.

Could you possibly have a defective amp also?

 

I disconnected the sub and the problem is still happening... any other ideas???

:cry:

-Nate

 

I used to have a 600a4 and mine did the same thing. It didn't ever cut out, but it would get so hot that you couldn't touch it. At that time, it was running a pair of Pioneer Premier components on the front channels at 4 ohms and a pair of Pioneer subs on the rear channels at 4 ohms. You could fry an egg on that thing after it had been on for a while. The Rockford did pretty good running this stuff but I knew all along that it wasn't a clean amplifier, it was a power amplifier. I did not really notice this until I got my 4Runner and tried running my new Diamond Audio components and coax speakers with the 600a4. Sounded pretty good at low to mid volume levels. At high volumes, it was very distorted. The tweeters hissed and the mids were pretty muddled. I attribute this to the fact that the Diamonds are a much higher quality speaker than the Pioneers and much more sensitive to distortion. Don't get me wrong, Rockford amps are pretty good for running subs but terrible for your mids and highs. Rockford amps are power hungry and I don't think that the basic Punch series amps are efficient enough to dissipate all of the heat that they generate. To make a long story short, if you are using Punch series amps (the punch power series may be better), they are gonna get hot so my advice is not to touch it or replace it with a more efficient amp. If not, you may try wiring a fan into your fuse panel and mounting the fan under the seat to remove some of that heat. Hope this helps. Later.

Matt

 

To keep the amp cool you could use an old power supply fan from a junk computer (they run 12V)

 

Could this problem be caused by a bad ground and if so what is the BEST way to fix it?

-N8

 

Nate, what guage wire are you running into the amp for power?
The ground should be the same size as the power lead.
In my photo here you can see I have 8 guage wire going out of each distribution box to the amps, but I have 4 guage coming from the battery to the box, and 4 guage also for the ground.



Also under that 4 guage wire for the ground the paint is scraped real good.
You could check the ground and see if it's good. My amps get warm too, but not super hot.
Corey