I guess the bigger question is why are you concerned with THX certificaiton for speakers? As Yoyo said, its really just a marketing thing. A "THX Certified" speaker setup isn't neccessarily better than one that isn't, it just means that that company chose to pay THX for the use of the THX license, and the other didn't. Yes, there's a minimum standard they have to meet, but it doesn't mean much.