The main goal, if possible, is to have the tweeters of your left/right/center to be at ear level when seated. Often, this is not possible with room placement, so do the best you can. If the center is below, you can angle it upward. Many of us flip the VP150 cabinet over and use the built in angle, just make sure you fip the grill cover over so "Axiom" isn't upside down. \:\)

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85