I am currently using an Energy e:XL-S10 10" subwoofer in my home-theater and main stereo systems (same room) that I am very happy with. Now I am considering the addition of a subwoofer to my second stereo system, where I have Energy e:XL 25 floorstanders. I could go with another e:XL-S10, but at the typical dealer price of $450, it's a little more than I would like to spend for my second system. At $450, it would be more expensive than the NAD C 350 integrated amp I am using in this system. Another alternative is the Energy e:XL-S8 8" subwoofer for around $300, which I have used and have been impressed with. The e:XL-S8 would probably be more appropriate for the second system than the e:XL-S10 not only from the standpoint of cost, but because my living room where the second system is located is not a very large room in comparison to the home-theater room. I'd probably be happy with the e:XL-S8. Yet another alternative is the Sony SA-WM40 subwoofer, which is only $200 at Best Buy. Many people here seem to rave about its performance. Has anyone compared it to the Energy e:XL-S8 or e:XL-S10? The price of the 'WM40 is just right for the second system, but the fact that it has a 12" woofer concerns me given the size of my living room. Would I be wasting my time with the Sony SA-WM20 8" subwoofer? It's only $100 at Best Buy. Does the 'WM20 provide similar bang-for-the-buck performance as the 'WM40? At such a low price point, I wonder if I'd be giving up too much in going with the 'WM20. If I do get a subwoofer for the second stereo system, I will need a crossover box to allow connection to the NAD C 350 integrated amp. The C 350 has no direct subwoofer input. I use a crossover box by Energy in my main stereo system to connect the e:XL-S10 subwoofer to an NAD C 370 integrated amp. With the e:XL-S10, I can bypass the internal crossover and dial it in via the external box. In looking at pictures of the Sony 'WM40 on Crutchfield's web site, I don't see how this can be done. Is it possible to bypass the crossover on the 'WM40? If I were to get the 'WM40 and find it to be a really good subwoofer, but too big for the living room, I could always move it to the home-theater room and bring the e:XL-S10 to the living room. However, if I cannot bypass the internal crossover of the 'WM40, the point is moot. Also, I guess I am biased, but I would have a hard time accepting that the $200 Sony 'WM40 bested my $450 Energy e:XL-S10, even though the former has a larger woofer.