Due to the weird construction of my media room, I have pre-wired speaker locations for my rear surrounds that are about 6 inches away from the side walls essentially in the corner of my 13x17 media room. What rear speaker would be best for rear surrounds: the MPX, the 7000's angled toward the middle of the room or just 650's? Or for that matter, would an on wall super sat be better?

FWIW, the plan is for an Atmos setup with Triton Twos as LR, XXL center, MPX surrounds, and 7000's for ceiling with an SVS 2000 sub that I already have for a 7.1.4 setup (7.2.4 if you count the Triton 2 subs

Nicklao,
I can't tell you, but I am sure some guys here can, or the Moderator Dude can.
Sounds like it will be a really good system, please let us know what you decide and how it works out.
Have fun with it,
God Bless, Wayne

nicklao wrote: Due to the weird construction of my media room, I have pre-wired speaker locations for my rear surrounds that are about 6 inches away from the side walls essentially in the corner of my 13x17 media room. What rear speaker would be best for rear surrounds: the MPX, the 7000's angled toward the middle of the room or just 650's? Or for that matter, would an on wall super sat be better?

FWIW, the plan is for an Atmos setup with Triton Twos as LR, XXL center, MPX surrounds, and 7000's for ceiling with an SVS 2000 sub that I already have for a 7.1.4 setup (7.2.4 if you count the Triton 2 subs

Rear corners are fine places for the surround channel in a 5.1.4, not so much for a 7.1.4. You'll want surround channels at ear level too, so Invisa MPX in-wall or SuperSat (or Aon) on wall is going to be best for that I would think.