its says they gain PW with a range of 4 ....does this mean you cut the range in half when doing the pulse wave
so now they have a range of 2?

correct

blah blah blah /filler

They gain pulse wave.
They gain whatever range is indicated.

Pulse wave halves the range of a figure using it. There is no reason to believe that these figures would be an exception to that rule.

wasn't thinking they were, i was just wanting to make extra sure i was doing it right.

Just so you're sure to take full advantage of it, The Flash and Liberty Belle from Crisis get Pulse Wave with a range of 8, not 4.