Overheated amp

Jason Merrick · 08-26-2003, 10:02 AM

I've had this amp in my car since February, and haven't had a problem until now. The other day, while driving home from a local HTF meet, my amp overheated and went into protection mode, shutting off all bass. It's a 150w RMS MTX amp powering a single Kenwood Excelon 10" sub in a sealed box. Is there anything I can do to keep the amp cooler? Other than turning it down, that is! I was not cranking the volume any louder than I normally do and the car wasn't especially warm, although it has been hot here all summer.

I can't find the picture I have of the amp, but in the picture below, the amp is mounted to the back of the seat, directly behind the sub.

Jason Merrick · 08-28-2003, 08:57 AM

Found the picture of my amp, is it too close to the box and unable to get enough air? Would moving the box forward a few inches help? What about moving the box to the driver's side of the car and leaving the amp exposed?

Anyone?

brentl · 08-28-2003, 09:38 AM

You shouldn't have any problem, you have lots of space.

Are you sure it's overheating?? Has anything changed that ay have caused it??

Is there a possiblility that you may be running the amp bridged with 2-4ohm voice coils in parallel so the amp sees a 1ohm load??

That would be my first guess

Brent

Jason Merrick · 08-29-2003, 09:13 AM

I don't think my sub is dual-coil, but I'm not 100% positive. However, nothing has changed in my system since I bought it in January and it's worked fine until last Saturday. It definitely overheated, when I pulled over to check it out it was scalding hot to the touch and I could even smell it a bit in the car.

It's worked fine since it cooled off on Saturday, but I just don't want to keep pushing it and end up damaging it if there is something I can do to prevent that.

Andy Hardin · 08-29-2003, 11:27 AM

You might try repositioning the sub away from the amp, just to get some airflow there. Especially in the summer.

You can also get a small 12v fan and mount it there to blow air over the amp if you really want to do some work. I would try moving the sub, getting some airflow, and see if that helps.

brentl has a good point with the ohm load too. Make sure your amp isn't seeing too much.

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brentl · 08-29-2003, 07:30 PM

I asked because they offer the Excelon 10" in both both Ohm and dual voice coil 4 Ohm.

Brent

scott>sau · 09-02-2003, 03:29 PM

Jason, definately use a fan if you keep the amp in its present location. At least your heat sinks are vertical. You could also run tubing from your AC to cool the amp down. Don't laugh I have seen folks at ISACA shows run freon lines on their mosfet rails. That is a bit extreme. Amps have internal thermisters that shut them down for heat. But if the heat is not generated by the environment than it is an impendence issue. Since you have just one sub I doubt the amp is going into dangerously low loads. If it's DVC run it two-channel bridged stereo.

Jason Merrick · 09-03-2003, 12:41 AM

Thanks Scott... I'll look into that as well!

brentl · 09-03-2003, 08:07 AM

"If it's DVC run it two-channel bridged stereo."

Doing this on an amp that will only handle a 2 ohm load will most definately shut the amp down quick!!

Brent

scott>sau · 09-03-2003, 09:12 AM

If the amp can handle a lower impedance than 2 ohms it would be stable. Some amps can do it, some can't. And the determining factor is the impedance of the driver/drivers.

This is an edit: I failed to mention that if Jasons amp is a 2-channel and is bridged mono it would cause problems with his DVC driver. If his amp is 4-channel and run 2-channel bridged stereo to a "dual" voice coil driver it would be more stable.