Let me guess....system was swept to 550(by experienced people) and now you think you can just swap 750/860 hardware in and presto. Nah....look behind the return amp and find a couple of mods to test on. SA gear does this if you don't know how it works. Sweep is not hard if you understand why you are doing what you're doing. It's not just a picture.
This is CABL.com posting #189628. Tiny Link: cabl.co/mXuG