why does the red protect light comes on my kicker zx 750.1?

[D block]

when i turn the volume up the protect light flashes when it hit deep notes the gain and bass booster is at 45% the xover is at 0 im using the zx 750.1 to power 2 kicker L5 12's they are dual 4ohm and i have each wired to 2 ohm and connected both sets of wires to the amp it still plays when the red light is on is this good or bad if so how can i prevent it thanks