Hey, I currently have a set of Logitech Z-540 computer speakers and want some information in case I ever want to upgrade them...well, actually, WHEN i upgrade them. I am curious as to the power of the 4.1 sub. Is it the same as the 2.1 sub? I don't want to lose the power I ahve now with my Logitech sub. At least I know it will sound clearer. Here are Logitech's specs. Not very detailed at all. They don't even tell you it uses a pressure driver instead of a long-throw woofer.
http://www.logitech.com/index.cfm?page=products/details&contentid=5045&CRID=2&detail=2&countryid=19&languageid=1