Are the amps bridged or running each sub in stereo?
Also, if the amps are 4 ohms and the speakers power output is rated at 2 ohms, you wont realize the potential of the speakers since they will only receive loads of 4 ohms. Even if you run the amps bridged, they most likely bridge to 4 ohms. I think you may only be getting half the rated power of your amps at 4 ohms.
I wouldn't start cutting anything yet! You need to verify the power rating, output rating, and actually load the subs are being driven with.