Help with 10' x 15' HT design

Hello. One observation is that 10' x 15' will cause serious acoustic concerns. 10' and 15' are both even multiples of 5. You want to avoid even multiples when considering length, width and height.


So a 18' x 24' room is bad, 12 x 18, 11 x 22, etc... all problematic.


10x14 isn't perhaps so bad, but still even multiples of 2. Better perhaps would be 10' x 14.5'

With 1080p you will have easy opportunity to scoot seats a bit if need be.

Main seating at 10 ft may help you moderate some of the potiential stupids with room modes. Don't sweat it, just be prepared to move subs / mains a bit to help with seat to seat variations in lower frequencies.


As you may know, typically anything up against the wall is a "throwaway" seat as far as audio goes.

Thanks for the responces guys. I think I'm going to go with a 100" dia. screen with only one row of seating (4 across). I'll put these at 11' from screen. I can use some bar stools behind these for additional seating.

Look at my sigs for more info/inspiration on small theater builds, which is what you have.


Victor

Yeah, ok it is spelled "multiples"


Also, all of the above is predicated on the dimensions being the actual low loss acoustic dimensions of the space. Think fully reflecting walls as opposed to lossy or absorptive.


EDIT: can't spell fer ....

I will apologize in advance as I am using a darn cell phone and tiny keyboard so I can't really get busy with the whole cut and paste thing at the moment.


One point was that both 10 & 15 have a common factor, which is 5. Therefore they are each integer multiples of that factor. As a result, for example, the second width mode would be the same frequency as the third length mode -- if I am thinking clearly ( could be iffy). And I am surprised that Bob's calculator doesn't see that one. I will double check all this later.


You have also discovered the beauty of "rules" for rooms. That is that there are so many of them! Bonnello crtieria, Bolt, BBC (Walker), .....Some interesting work also came from Salford U ok this very thing not too long ago ( I'll hunt for the link).


Ok- enough of this keyboard-



Quote:
Originally Posted by jamin /forum/post/15482110


One point was that both 10 & 15 have a common factor, which is 5. Therefore they are each integer multiples of that factor. As a result, for example, the second width mode would be the same frequency as the third length mode -- if I am thinking clearly ( could be iffy).

Click to expand...

You are quite correct. There is overlap at 113 Hz, 226, etc.


It may also be useful to point out that these mode calculators assume all modes are excited equally and heard equally. That is not the case in actual use, so the sonic effect of these modes cannot be known until the room is evaluated based on actual speakers and seating locations. Your earlier point about wall construction affecting the modal response is another variable in the final equation.



Quote:
Originally Posted by Roger Dressler /forum/post/15482002


Yes, I am aware that when room dimensions are even multiples of each other, it can cause problems. But 15 is not an even multiple of 10. ..snip......Then I plugged in 15x10x8 (I'm not sure what Jeff's ceiling height really is), and while it is not optimal, it doesn't appear to cause "serious acousticsl concerns ." ...snip..

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Ah yes, bold and snips are mine and I agree --