Amp and sub Help Asap

I picked up a ported double 8" box today with an alpine mrv f545 and two 8" arc audio subs. I know it is a cheap system but I got it for a great deal and just wanted to add a little more thump to my truck. ( one of the biggest things I miss about the mustang).

Tonight I installed everything and got it all hooked up. Everything comes on the display on the amp stays around 13.1-13.2 but the subs are barely thumping. What could be causing this issue. It has to be something in my install.

Only thing I am thinking it could be was not good enough wire or bad ground. I grounded to the seat in the back.

I know it works well because I took it to best buy and had a friend test everything and it was pretty decent there. So what could I have done wrong?

I ran power and remote down drivers side and ran rca's down pass side. and like I said ground is to one of the seat bolts that holds the top of the seat to the bottom.

 

Also I checked the settings on my head unit and they are fine. I even turned sub gain up to 6 on the pioneer. There are no controls on the amp itself that I can see.

 

Hang on I found the owners manual online. There are settings for specific radios to follow. Gotta take off the top cover

 

Got it all set