room treatment behind TV?

I just recently built some DIY open baffle speakers.  I love them but I'm wondering, because they are dipoles, would my room benefit from more acoustic treatment on the wall behind the speakers?  I have bass traps in both corners but I'm thinking of building one or 2 skyline diffusers on the wall.  However, I have a big 40 inch TV that sits between the speakers.  Would this be blocking the reflections coming from off that wall?  Would having diffusers there make any difference if the TV is blocking those reflections?  Removing the TV is not an option :)

thanks