1994 Chevy Silverado Build

[Kory]

Hello everyone.My name is Kory.I own a 1994 chevy silverado 1500 regular cab.I am redoing the audio in it and so far i have put in a Pioneer deh-x6700bs radio, a pair of Rockford Fosgate p152s 5.25" component speaker set, and 2 Rockford Fosgate R1s410 10 inch subs. I am getting ready to buy the Rockford Fosgate r400-4d amp for the subs. I recently bought an Soundstorm lab 10" subwoofer.My problem is this.I have 2 boxes already made and done for the fosgates and they are behind the seat.Does anyone know deminsions on a box for under the seat or another place to build a box and put this sub?pics would be greatly appreciated! Thanks1