Would I still get good sound if I just had one sub instead of two and then this box
http://subthump.com/Chevrolet-GMC-Custom-Subwoofer-Boxes/Chevy-Silverado-and-GMC-Sierra-Extended-And-Double-Cab-Sub-Enclosures-by-Subthump/99-06-GM-Extended-Cab-Ultra-Deep-Single-1012-Downfire-Box.html