I have a trio of GR Research AV1+ speakers. I currently have all three speakers leveled at ear height with the front L & R speakers standing straight up and the center on it's side. What I'd like to know is there a preferred way to mount the center channel? Is on it's side the preferred way or is standing up like the front L & R speakers. Mind you that standing up will take the center channel tweeters 5" below ear level as opposed to being at ear level.