I plan on building a pair of 1 cubic foot sealed subwoofers' with the ScanSpeak 23W/4557T-02, 9" Aluminum Cone Subwoofer and ScanSpeak 23W/0-00-02, 9″ Subwoofer, Passive Radiator. The design goal is to build a box with as shallow a depth as possible without compromising performance. I hope to...