I put this in my theater build thread, but i think a dedicated thread may get more attention, as there are a lot of people asking questions about ATMOS placement..
I plan to use RSL C34E speakers for atmos. I pulled from their website the vertical dispersion. looks great through 45 degrees, and still pretty darn good up to ~60 degrees...
Ceiling will be roughly 8'6". Top row listener height is ~38" from ceiling, and bottom row listeners is ~54" from ceiling. In my case, i want to optimize for both rows to have a good listening experience. Why? because in 2.4:1 widescreen mode back row should be MLP and for 16:9 mode the front row will be MLP, but i digress...
The RSL have a 15 degree angle built in, so they project out more in the direction pointed and less in the direction not pointed. So i adjusted my forumlas accordingly to calculate where the dispersion will be forward and backward as a result of the angled speaker. My calculations for good sound coverage are as follows:
60 DEGREE COVERAGE (shown in blue in picture below)
for bottom row listening height:
max distance from speaker (direction pointed): 54" * tan(75) = 16'9"
min distance from speaker (away from direction pointed): 54" * tan(45) = 4'6"
for top row listening height:
max distance from speaker (direction pointed): 38" * tan(75) = 11'9"
min distance from speaker (away from direction pointed): 38" * tan(45) = 3'2"
45 DEGREE COVERAGE (shown in green in picture below)
for bottom row listening height:
max distance from speaker (direction pointed): 54" * tan(60) = 7'8"
min distance from speaker (away from direction pointed): 54" * tan(30) = 2'7"
for top row listening height:
max distance from speaker (direction pointed): 38" * tan(60) = 5'6"
min distance from speaker (away from direction pointed): 38" * tan(30) = 1'8"
So I mapped this in two pictures...
Sound coverage if sitting with ears 38" from ceiling (back row): Looks like back row gets decent coverage from the rear speakers, but not so much from the front speakers.. This may be the best i can do...
Sound coverage if sitting with ears 54" from ceiling (front row): Looks like front row is pretty well enveloped by all 4 speakers in this arrangement.
Questions:
Am I doing this right? Did I interpret how the RSL speakers project their sound correctly?
Does anyone disagree with placement of ATMOS?
Does anyone disagree with the direction i have my ATMOS pointed to maximize coverage to all seats?
There is a lot to consider here, and I'm not even sure if I understand how the speakers work... Some validation would be great
