Atmos 5.1.4 Ceiling Speaker location (1 Viewer)

[Bryce_H]

Hey all,
So I recently upgraded to a Denon AVR-X4300H and am not looking to add the ceiling speakers for a 5.1.4 Atmos/Auro-3D setup. Through reading of various articles is appears Atmos has some of the more restrictive speaker locations, so I figure I would use that as the basis. Below is a correctly scaled depiction on my theater room.

A couple quick numbers/legend

Room dimensions 18' X 9'7"
Ceiling height 8'

The bipolar surrounds are mounted 6' (on center) off the floor and 9' back (90 degrees to my head)
I have 2 rows of seating, 1st row ears are 9" from the front wall, 2nd row ears are 14' from front wall.

Based on Atmos set-up speaker placement guide for a 5.1.4 (https://www.dolby.com/us/en/guide/dolby-atmos-speaker-setup/5-1-4-setups.html) I understand the front in-ceiling speakers should be should be 4'10" in front of me (based on 45 degrees).

My question is:
1) How far into the room do I mount the ceiling speakers? (the red A below)
2) How far back do I mount the rear ceiling speakers (the red B below). The math in the guide doesn't work (i.e. side surrounds 90 degrees from listener, but ceiling 125-150 degrees back from the listener)

Any help is appreciated.

 

[Sam Posten]

Look, you can drive yourself crazy trying to make a perfect location or you can make it work and rest easy that Audessey will correct it as needed.

If you can get the wires run I definitely recommend in ceilings. If a construction klutz like me can do it, anyone can.
https://www.hometheaterforum.com/community/threads/sams-underground-aerie.319456/page-4#post-4501275

Just don't do what I did and try to make the cuts too tight. Give em room to breathe.

 

[Race Bannon]

Pretty sure the rear ceiling speakers would go the same distance back, i.e. 4'10" in your picture. that 135 degrees thing just means 45 off the vertical axis.

 

[Race Bannon]

As far as the A dimension, Dolby shows that as inline with fronts, if possible.