need to wire subs to amp

I need a way to wire my subs to my amp correctly. I have a Mtx Audio Thunder 2150X  Amp. It is a two channel amp. The specs on it:

RMS Power measured at 12.5 Volts DC:

I am wiring it to a Mtx Audio Thunder 5000 sub box, it has 3 10" subs in it.In the back of the sub box it has a black + and a red -, and on the amp it has terminals R , + and - ;  and L + and -.  Everytime I try to wire it the amp gets hot which I know is not good. What is the best way to wire it up and get the best power out of it?  Also there are 4 terminals on the amp for hi-level speakers. what is that for wiring to? Any help would be appreciated.

I looked the subs up at the mTx site and saw that the 10" woofers were made in either single 4 ohm, 8 ohm and 12 ohm.  Hope yours are the 12 ohm models.  You need to pull the subs from the enclosure and check resistance across the terminals...find out what ohm resistance each of them are.  The site shows that the DC ressistance of each is 9.02 ohms.  Three 12's wired correctly, like shown, will give you a 4 ohm load, which is what your amp will work with.

The other two possibilities, the 4's or the 8's, will not work for you, because three of those are wired to lower ohm loads.

You won't be using the high-level speaker inputs.  Those are for use when you cannot use RCA's from the head unit.  For wiring to your sub box, the amp should show a diagram for bridging.  Neg should go to left neg on the amp...pos goes to right pos on the amp.  If you have a total 4 ohm load with those three woofers, the amp should make a total of 300 watts, or 100 to each woofer.

Look at the wiring to each speaker, too.  If you picked up that box/woofer combo used, you don't really know what you got.  In fact, be sure those subs are actually MTX.

http://www.mtxaudio.com/caraudio/archive/thunderSub51012.cfm