I picked up what appear to be a fairly rare pair of Fisher XP-4a's today as a consolation prize after missing out by about 10 minutes on a score of a lifetime by another AK member. Hopefully he will post on his find. In any case I bought these XP-4a for no other reason than they are in mint condition and it appeared they were made during the high mark of Fisher's audio legacy. To this point all I know is that they appear to have only been made between 1963-64 and would have run you about $200 each for the Walnut finish. They are a 8 ohm 3-way but I don't know how efficient they may be. Early listening with Marantz SR- 7500/ Denon 2910 combo is positive. They are getting better as I put time on them. Any additional info you can share on them is appreciated.