hello, i have two rockford fosgate subwoofers that push out 500 max watts and 250 rms watts. my amp is a pyramid amplifier and pushes 1000 max watts and 500 rms bridged. i have it hooked up at 4 ohms and is only 75 watts a channel. my question is, can i bridge both speakers to make it better, or will the speakers blow. and by the way, i have the gain level on the amp at about 70-75%. thank you