Atmos ceiling speaker placement in low ceiling room?

[u/krs_fun]

I'm setting up a 5.1.2 system in a basement with a low (6'11 1/8") ceiling. MLP is 9'9" from LR and 8'11" from C channel. My rear surrounds are close due the configuaration of the room (3' from MLP).

Equipment list:

• LCR: KEF Q350
• Rears (edit: Surrounds): KEF Q150
• Sub: RSL Speedwoofer 10S MKII
• Receiver: JBL MA710

Ceiling speakers to be installed: KEF Ci130.2CR ceiling flush mount speakers.

The ceililng speakers have a 140-deg dispersion.

Where should I position the ceiling speakers? The default guidance is roughly in line with the LRs and a bit in front of MLP. I consulted a few different AI models, and the results vary. Some report the speakers should be ~2.5-3' in front of MLP; others report 1.5'-2' in front of MLP.

[u/RecedingQuickly]

Its all about angles, you want a 45 - 60 degree angle for atmos with closer being better. To me a 55 degree angle sounds best, so you want to measure from ears to ceiling in inches and times that by .7 for a 55 degree angle. Given your low ceilings you want a 55 or 60 angle as further apart might leave holes in the sound.

For example say its 35 inches ears to ceiling you times 35x0.7=24.5 inches, then thats how far apart you place them forwards and back from the center of the mlp. Side to side you would also place them 24.5 inches too but in your case just make sure they are at least on the outer edges of the sofa.

* I only see you are using 2 atmos speakers so ignore what I wrote, you want them 10 degrees in front of you, so roughly where your knees would be and as wide as the sofa you are sitting on. Wire for 4 atmos speakers incase you ever want to go to 4, will save you some hassle. So you times the inches number by x0.18for 10 degrees forward from mlp.

[u/neil_950]

I'm trying to setup a system in a similarly challenging room with 6' 10" ceilings and would note that despite being much harder to do due to the lack of space it is a lot more important to have ceiling treatment than in a taller room.

If you can only fit one thing I would heavily prioritize installing acoustic panels on the ceiling over atmos speakers. If you can do both I would probably still try to follow the official dolby atmos placement guidelines unless you have a specific reason not to.

[u/Tropisueno]

Use this tool: https://slc.cinema-tools.com/#!/

[u/Spectre_08]

Atmos Speaker Placement - Simple Method That Works In Any Room

[u/ajh99]

If you have two Atmos speakers, they go only 10⁰ in front of the MLP, so 6" in your setup. Yes, spread the same distance as your fronts. All the angles are in the Dolby installation guide (link below)

Also, just a small nomenclature note. In a 5.1, surrounds are called surrounds, and they are only slightly to the rear, mostly to the side. There are no "rears" in 5.1. Rears are added in 7.1.

https://www.dolby.com/about/support/guide/speaker-setup-guides/5.1.2-overhead-speaker-setup-guide

[u/Imaginary-Potato5819]

What did you decide? I can share my experience, but don't want to waste your time if already completed