Max,
> The attached file shows my first stab at a floor plan for my new home theatre. <
I don't see anything attached.
> this makes the room pretty large, with wasted space at back. Is there any way to decrease size of room. <
A large room with extra space is not wasted! It helps acoustically, as does being farther away from the wall behind you.
> what would be the affect if I build two equipment rooms in the back corners? <
You'd be putting stuff exactly where bass traps need to go. Not recommended.
> What would the recommended ceiling height for this room be? <
The dimensions you proposed above are already very good.
> What would be the estimated cost to install the correct real trap products for this room? <
It depends entirely on how much you're comfortable sending versus the type of results you're hoping for. Generally, one of our Room Kits would be a good choice. I'm glad to talk about my products all day, but forum operators are usually not keen on having vendors use their forum as a sales room.
So best is to look at our Products page:
www.realtraps.com/products.htm
And also follow the link near the bottom to our Room Kit descriptions. Then email me directly from the Contact page. I'll be glad to make sure you get the best combination of products for your room.
> I read in a Home Theatre design book (A to Z Dedicated Home Theatre Handbook) that you need a wood sub floor to help with base. <
I can't imagine why that would be true. Not saying that a wood floor that flexes is the same as a solid concrete floor. But there's no reason you can't get excellent results with cement.
--Ethan