wiring 2 kicker compvx's to rockford amp

I have just recently bought 2 10" Kicker CVX's ( Kicker CompVX), they are 4-Ohm DVC model and to power them I went with the Rockford Fosgate T1000-1bd ( Rockford Fosgate T1000-1bd) Right now I have them wired up like diagram 1 according to this ( Wiring Diagram) I've had it the other way too but this way seemed to work better. The problem is you have to turn the gain on the amp up almost all the way to get a decent sound out of them but it's still not near what it should be and I would think you shouldn't have to have the gain turned up near that far in the first place. This is the first set of DVC subwoofers I've had so I'm not sure what the problem is. I am running 4 gauge wire like its says in the manual for the amp and I've checked my wiring atleast 3 to 4 times. Hopefully someone can help me out with this because I am stuck.

What kind of box are they in...?M.E.C.P & First-Class

Go slow and drink lots of water...Procrastinators' Unite...Tomorrow!

I would double check that they are wired to 1 ohm. Like tommy may have been implying, the box may the problem

Sorry meant to reply back sooner but if anyone cares to know it was definitely the box, I put them in a bigger box and now they sound great. They are in a 92 camaro so I didn't have a very big box since the space is kinda limited in this car, which didn't matter that much with my old speakers because they were pretty shallow and didn't need near as much room as these kickers. I found some plans for a box that fits perfect in my back hatch area so now they have plenty of room. Anyway thanks for the quick replies I appreciate it.