http://www.jblproservice.com/pdf/Vin.../UREI-813B.pdf I have a friend who is starting to build a pair of crossovers for a diy 811B project. The only schematic he could find is attached (last page) and has a few unreadable values. Does anyone have a better schematic, or if you have a pair, could you please check the value of C3 and C4 and let me know? Thanks in advance.