Thanks for the reply Michael. I'm certainly no expert in what makes one speaker sound better than another. I agree that the RS-35 probably has other attributes due to its larger woofer, it just seemed odd to me that, concerning the one parameter of bass extension, it would score lower(albeit negligibly lower) than the RS-25 which has a woofer that is 1.25 inches smaller in diameter. In fact the RS-10 has basically the same extension as the 35, and it has a woofer that is a full 2.5 inches smaller. On the other hand the RS-7 which has a woofer only 1.5 inches larger than theRS- 35 extends down to 49 Hz, a value rivaling a lot of mains. I guess I always incorrectly assumed that for a given speaker manufacturer's line of similarly designed speakers, as those in this family, larger woofers meant deeper bass extension in the bandwidth spec. It seems the more I know the less I understand loudspeakers! I feel your comment about the rear channels not needing much bass extension, Michael (probably just much obsession about nothing on my part), but what about music mixed in surround formats like DVD-A or SA-CD, do they not utilize the rears for lower frequencies?To see the spec comparisons of the speakers discussed above go here: http://www.klipsch.com/media/Products/Ref%20Brochure.pdf