I have a ported box with a JL Audio 10W1 in it (professionally built to spec) in my Subaru 2.5 RS sedan. I am powering with an Alpine MRV-F450 5 channel amp (50w X4 & 200X1 @ 14.4). The sub is just not kicking. What can I do? I have the gain turned all the way up. BTW I am using an...