If you have a rectangular room who have to try this out. I came across it on the Cardas website. I thought my system sounded fantastic already, but this mathamatical calculation for speaker placement made my system completely open up. I was dumb founded at the before & after effect. I kid you not!! My room is 13x32 & it has never sounded better. If you have the room - DO IT!! He also gives speaker placement calculations for other shaped rooms. Check it out!!