I'm glad I read this thread as I have been looking for a sub as well. My speakers start to cut out around 60-70 hz ( they are full range Fostex 103's, which are itty bitty 4" speakers, in a zigmahornet enclosure). I love their sound, but I need something else to help out the little guys, and I've heard that they integrate very nicely with a decent sub. I was considering building one out of an Adire audio shiva, but I don't have the tools in my apartment. (I built my current speakers though, so it would be possible).
Would something like an S8 or S10 hit those somewhat higher notes acceptably? Also, I can only find S8's and s12's on the net right now, any sources for the S10?
Good topic anyhoo.