18 seems a little hot to me, lets say your going through a 2 way thats 3.5 db + your cable loss on drop maybe 1 db so i would say you probably have 22db on channel 2 at the tap if its tiling and your getting slow speeds on a modem if they have one your levels are to high remember 5.5 db loss on high end. i maybe wrong but i doubt it.Your to hot.
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