After reading thru these posts until my head was spinning, I decided to go forth with my first DIY sub project. I'm an accomplished woodworker, so building the enclosure is not an issue. Unfortunately, I have no experience in building a speaker. I'm planning to use the Tempest in a sealed box based on the Adire plans, with the PE 250W amp. It will be used primarilly for movies, since my main speakers are a pair of Genesis IIs with an 8" woofer and a 10" passive radiator, which give me plenty of bass for music. My question is this...do I need any other parts or components for the subwoofer, like a crossover or equalizer? It seems too simple and cheap with just the driver and an amp!