Greetings Dan, I am bi-amping a pair of KEF series 3-2 speakers. The back of the speakers have two seperate sets of connection posts for this purpose. For the top half, which is dedicated to mid's and high frequency, I utilize a Conrad Johnson Premier 11 tube amp. Tubes just can not be beat by soild state or FET in mid to high range. Now, for the low/bottom, or bass frequency I utilize a Conrad Johnson MF2250 FET (field effect transistor) amp. FET's are hard to beat for bass frequencies. I am VERY HAPPY with this set up. What ever you do, I recommend you stick with one manufacture of amplifier, and discuss your intentions with them, if possible. There are "issues" to be concerned about when bi-amping.
Regards, Lou