2 kicker l7 12's with a zx 1500.1?

Hello, i have 2 kicker L7 12's dual 4 ohm version, and would like to wire them down to 1 ohm.. But i Blew one previously when i wired them down to 1 ohm,, and would like to no what i did wrong to prevent it from happening again.. i have a average sized slot/ported box if you need 2 no.. (but i was playing hypnotize by young Jeezy at a high volume, so i no were at least to start ha ha..) Does anyone have this same set up or atleast can tell me were to set the gain ,xover ,and b-boost.. thanks