Thanks, This is good info for me to start with...thank you...for me as a total amateur this is way over my head, but I can work with someone nearby who understands the details electronically. I had heard that Irving M. Fried (Bud) would change out parts of KEF crossovers to his liking for the Fried line making them unique to that series line...I would like to upgrade my R series I up to R series II which have a far superior crossover sonically (woofer to mid) as mentioned in vintage Fried literature. What was particularly different in the actual parts, I don't know, I'm still searching for details; if I can get schematics or what parts were changed in the crossovers, the crossovers can be constructed new from Falcon. The new Fried and KEF companies currently have no remaining vintage data about this. I apologize for my lack of knowledge on the subject...hoping to learn more and the detail as provided can help me; maybe with proper measurement as suggested, with respect, my current crossovers can be modified. If I had access to a "parted-out" set of Fried Model R Series II speakers, the problem could be solved by examining/using those crossovers! - Thank you