Hi bdp. Thank's for the suggestion. I'm afraid that I don't agree completely with you. If I lower the sensitivity of the woofers I need to use more power, more power equals more expensive amplifier (perhaps noisy fan cooling), and the distortion number can raise quicker (maybe, maybe not), and they "only" need to handle frequencies above 60 Hz, below 60Hz my TC 2000 15" is going to take care. I also like the idea of using a bigger surface to move gently the air, than a smaller one moving the air in a more violent manner. Those this assumption makes any sense?