Ok, I described the "test" earlier. This is a subjective (non-scientific) test using some of my favorite music program material. No DVD's. NO DVD-Audio. No Super-Audio. Just regular CD's. Each main channel speaker contains a built-in 15 inch powered woofer (as well as two 1 inch tweeter and four 6.5 inch midrange drivers). The crossover is either 80Hz or 90Hz (I am not really sure which) to the powered woofers. There is no external sub. My room is pretty large, with valuted ceilings, and is completely open to the left and open almost entirely to the rear. I wanted to see how things would sound if I only used one of the powered bass sections. So I turned the sub volume down on one speaker (my right speaker), and I kept the sub volume at 1 o'clock on my other speaker (the left speaker). So basically, in this setup, both top sections of each speaker should be crossed over at 80Hz or 90Hz, with everything below this sent to the built-in powered woofer in the left speaker. I played some of my favorite tunes. The first tune I wanted to start off with was from the Gladiator Soundtrack. This soundtrack is great. If you listen to song 3, about 1 minute into the song, there is an awesome bass note which is played. I played this part of the song with my "test" configuration, and... WOW! What can I say, I was disappointed. It sounded decent, but normally the response is so smooth and I really feel like the bass is all around me. With only one powered woofer playing, the eveness and coherence of soundstage just did not compare to the dual woofer setup IMHO. I tried some other material. I tried some U2, "With or Without You". The "test" setup just did not compare to the normal setup. I tried some trance-type music, which have a very punchy sound. Same thing. I tried some rap music, the song "Crossroads" by Bone Thugs. Here I did not notice as big a difference, but still the eveness in sound which I normally get just wasn't there. I tried Sting's "Fields of Gold", as well as Dave Matthews "Crash". I still much preferred the normal presentation. I also tried these songs with the left speakers woofer volume level turned up a bit (to 3 o'clock), in an attempt to compensate for output differences when turning down the powered woofer in the right speaker. This certainly added more shake, but the coherence of soundstage was lacking compared to the normal setup. Strangely, on some songs, I noticed that my right speaker was brighter than normal. I really did not like that. On every single song that I played, the dual powered woofer setup sounded much much smoother to my ears. What can I say, the presence of dual woofers (compared to one) truly does seem to significantly change the sound of the loudspeakers, for the better in my case. Hopefully, people who have nOrh main speakers on top of nOrh subs, or ACI Jaguars on top of ACI subs, AV Reality speakers on top of AV Reality subs, Infinity on top of Infinity subs, Polk on top of Polk subs, etc. can try out this test and let me know how it goes...because I am not sure how valid my "test" really is.