system cutting off

I have finally got my 12w6 installed in my custom ported box, but  when i turn my volume up after long periods of time it will cut off and i have to let it set for a while for it to come back on. I am running an Alpine mrp-500 watt amp with 4 gauge wire throughout my truck and 12 gauge from the speaker. Any suggestions? And also, i just wrapped my box in vinyl and i was wondering if there was a cap or something else i could buy to fit around the port to clean it up a bit?

no, the amp doesnt shut off. its wired parallel and its a dual 4 ohm sub

my bad, it doesnt completely turn off, the light doesnt go off, the amp stays on but quits playing. its not hot or anything when this happens

I think that there is low voltage protection in that amp.  You need to check the voltage on the power and ground terminals of the amp when it is playing at the level in which it cuts out.  You must use the power and ground terminal of the amp when testing the voltage.

alright, thank you. i will try that today. What would you suggest if there is a voltage drop?

Were you playing the amp at high volume when you checked the votage?

no i was not, didnt think about that

Playing it at half vomume will not show you anything.  It must be playing at capacity to bull as much current as it can.  No current draw = no voltage drop.