Amp trouble, need advice,

[93STLTH]

I've got a Memphis Belle 16-MCH1300 5 channel amp. I might have wired something wrong, or it could be another problem, but my amp keeps cutting off if I run the volume anywhere around half way or higher. It seems to be a thermal cut out, the amp heats up and trips the cut out. If I turn the volume down and wait a while, it'll come back on. I'm running a pair of Pioneer TS-W3002D4 12" Dual 4 ohm Champion PRO Series Car Subwoofers. The subs don't seem to really be getting the 1100 watts the amp puts out. I've tried wireing them both in series and in parallel, but there doesn't seem to be much difference in output either way. Any guesses or suggestions?

[2fnloud]

This just start happening? Have you had the amp out of the car recently? Any other changes with the electrical system?

[93STLTH]

I replaced the Memphis Audio subs I had with the Pioneer subs. One of the Memphis subs blew and I couldn't find a single to replace it with. I had the same thermal cut out problem with the Memphis subs though. It didn't seem to be as frequent as it is now.

[mb3000]

Where is the amp located?

[93STLTH]

In the hatch area. I have it slightly raised from the enlosure I built, to help with airflow, but it's still not enough. I could add a fan for additional cooling, but I still think it shouldn't be doing this.

[ictponder]

Are your subs wires parallel or series?
Does the sub channel on the amp bridge internally?

NVM I looked it up. Even running parallel that amp is 1Ohm stable on channel 5 so I don't how it could be subs. Is your ground still good?

[93STLTH]

Hmm... I'll have to check the ground wire. It's under the enclosure I built, but when I replaced the subs, I pulled the wiring out and then ran the wires back underneath. It's possible I could have losened the ground wire.

[2fnloud]

Issac, Even if his ground was loose he mentioned that this amp would power off thermally. He needs to check his wattage while jamming on the system to see if voltage drop is contributing to the over heating issue.

[93STLTH]

I'm not seeing much voltage drop. I've got a 10 farad cap (yes, I know you guys frown on caps) with a volt meter on it and I'm not dropping any more than 2 or 3 tenths of a volt while it's cranking.

[2fnloud]

OK at least voltage drop is ruled out.

[hdorre]

What size power and ground wire are you running to the amp? Also, how are your gains set?

[93STLTH]

Running 4 gauge wire for both the power and ground wires. Not sure where my gains are set right now. I know I had to back them down some to reduce the cut out problem.

[R/T93]

I had to lower my gains as well, my Alpine PDX-5 (5 channel) would also overload when the volume was cranked.

[Streamln1]

I would still verify the ground is solid. If thats the weak point it will shut it down regardless of the fact that the input voltage is not dropping. Also, make sure that you don't have one of your mids / highs causing a short. If you know how to use a voltmeter, make sure each speaker is around 4 ohms and not shorted to ground. Any problems with the mids / highs will shut it down as well.

They are decent amps, I used to run one in my VR-4

[93STLTH]

I'll try that too, if the ground isn't the issue. I don't have much time to play with the car right now, I just moved into a new place and I'll be unpacking for some time. So it might be a while until I can try any of the suggestions.

[Vishnu]

What is supplying your amp it's audio signal? For instance are you using pre-amp outputs from an aftermarket headunit or are you using speaker level inputs? I have 2 amps in my car right now, a 4 channel that powers the main speakers and a class D Mono that powers the sub in the back.

I had the 4 channel wired with 4 rca's straight to my headunit and those work perfectly fine without cutting out. The sub amp however took a L/R channel from the 4-channel amp for it's audio in, and when I turn the sound up the sub would cut out, but the other speakers would be fine.

To fix this I had to run another set of RCA cables from the sub-out on the back of my headunit to the sub amp directly and I haven't had a problem since.

[93STLTH]

Thanks for the help guys, it looks like it was a ground problem. I had the ground connected to one of the interior panel screws, and I guess it wasn't making good ground. Drilled and tapped a new hole and reconnected the ground and it's cranking out the bass and no cut out.

[2fnloud]

sweet!!!

[Streamln1]

yep your ground is just as important as the power. Make sure you use a wire brush to strip off the paint under it too.