Summary: Puzzel to upgrade to enhance the digital nature with cost effective solutions. Abstraced the Bose Pro's comment as below: "there is one way and ONLY one way to make it DD. Call (800) 444-BOSE. They offer a DD upgrade where you send in your bass module and $500 and they send you a new upgraded DD and Videostage 5 sub. The reason this is (and why everyone's info is useless) is because Bose houses ALL the electronics except tuner and preamp in the bass module.