I built these last year and got outstanding results using an Ashly active xover. The drivers are (4) Eminence Alpha 15A's and (2) Tang Band W8-1808. These really do sound outstanding and considering the price of admission and how easy they are to assemble offer an amazing and unique audio bargain. If you read through my build thread linked below you'll hear my comparison of them to some very impressive production speakers. If you're in the DFW area (or willing to drive here) you can have the frames and baffles I built for free with the purchase of the drivers. One of the Alpha 15's has a little puncture in the surround but this could be easily repaired and as it is I could detect no effect on the sound or performance of the driver. $525 plus shipping and Paypal fees.