Here are some pictures of my Flexi Rack and Active Crossover. www.bluemarine.com.au/mark Check out the yachts while your there. The Rack is made out of Tasmanian Oak veneered MDF. I angled the sides back so it didn't look so boxy. I made rubber washers out of an old car inner tube, using a round chisel/punch and a bit of sharpended stainless tube inserted into a drill press (not turned on!). It's finished with 2 pack polyurethane floor coating (wear a respirator, unless your tough/stupid). I put the 5/8" allthread in a cordless drill and held steel wool around it to clean it up. The active crossover is a 3 channel (LCR), 3 way 4th order Linkwitz Riley. Crossing over at 110Hz and 2400Hz. The centre channel bass sums into the L and R bass signals. I got the circuit and pcb's from Rod Elliot at www.sound.au.com The crossover has made a big improvement over the main speaker's passive crossovers, especially in imaging, clarity, and it goes heaps louder without distress.