subs

Systems

i have 2 polk ex series II 12's. they are both 4 ohms, my amp is a kenwood 728s and it is a 4 ohm stable. it is rated at 300 watts by 1, 100 watts by 2 at 4 ohms, and 150 watts by 2 at 2 ohm. i want to bridge my amp but it will get really hot and shut off. how should i wire my subs so they will get the most watts and sound the best without blowing my amp or speakers? i will appreciate all the help i can get. my amp is 4 ohm stable so i can't put them in a parallel, is there any other way to bridge them? i've tried almost everything but after a while it will get hot and shut off no matter what i do.