Amp Getting Hot and Going Into Protection

This is my setup.  I have a 12inch solobaric L7 powered by a 1200.1 kicker amp.  I also have a 650.4 kicker amp (4 channel) powering kappa perfect component 6.1 in the front and kappa perfect 6x9's in the back.  Have 1/0 gauge wire (power and ground)  also high output alternator. Also a optima blue top.  Ground is good (real close to 0 ohms).  Here's the problem.  When I'm bumping the music (in the park), the bass amp works perfect but the 4 channel amp would get hot and go into protection for a few seconds then come back on and does the same thing over and over.  Bass amp just gets warm but the other amp gets real hot.  To troubleshoot, i disconnected the sub and blasted the 4 channel amp, it didn't get too hot and didn't go into protection.  Someone told me that if the amp isn't getting enough volts that it would overheat and go into protection, figuring that the bass amp is stealing most of the power and the 4ch amp isn't getting enough. Please help.  Also the power wire from the battery is going into a fused distribution box which is then going to the amp.  Hope I gave enough info.

If the vehicle is not running or the ingine is idling, your alternator is not keeping up with the demand placed on the electrical system. As voltage drops, current spikes so that the amp can try and make power still. This is making the amp work really hard. That hard work = heat. Go driving for awhile and post the results while the vehicle is in motion to see if it still happens.

It probably is the amp. Heat is a natural byproduct of the production of power. You put the amp in a trunk that is not vented. You use the amp for a extended period of time. You run the amp at full output. It is summer time (excess heat in the vehicle). All these things couple together to make a amp go into thermal protection. If the amp is getting that hot and going thermal on you, chances are it is the amp. Start by disconnecting one set of speakers from the amp and retest again. Look to a full range class D amp like the Eclipse XA4200 would be my suggestion.

There probably isn't anything wrong with how you hooked the speakers up. The amp is probably just going to get hot running at a 2-ohm load. The specs say that it can play at 2-ohms but they don't mention for how long. That is often the case with many amps unfortunately. I would reccomend the new Kenwood Class-D 4 Channel

Have you tried playing the system with the trunk open to keep the woofers from beating the 6X9s to death?  Does it still heat up?