I'm doing a project in my Physics class concerning audio, and I plan on building a subwoofer enclosure for my Adire Shiva. It will be run at 400w rms and I'm wondering what would be a good size box to build. My friend has his shiva in a 2.5cu.ft. enclosure, and I was wondering If I should go larger or smaller than his. We were thinking, try 3.5cu. and see what that sounds like, and also build a 1.2cu. to see how that sounds. so, is 3.5cu. too big for one Shiva?