Several months ago I was fortunate enough to acquire a pair of AR 9 Speakers in excellent condition with the exception of surrounds.   These were a one owner speaker, came with the original boxes, original sales receipt and two sets of manuals and all the brochures.   I have had the surrounds professionally replaced and all speakers tested.   The cabinets are close to new showroom condition.   So I have read a lot about the crossovers, both on this site and talked to many local audio pro's