New construction HT - what should be the highth difference of each seating level? Using two rows of seats with a front projection system. 21 x 15 foot room size with 9' ceiling above the highest riser.
Average highth is approximately 6-8" some have more some have less, but it really depends on the seats in front. Do they have a high back or low, back, it sums up to this. It all depends on your individual circumstance, and there is no right or wrong answer.
My theater will be similar in size to your's at 20' x 17' x 9' 6". I'm planning a 13-1/2" riser, (2x12s decked with 3/4"-1/2"-3/4" CDX) though various factors will come into play when determining the right height for your room.
You'll need to take into account the type of seating, screen height, tallest person you anticipate sitting in the front row, etc.
For a good discussion on methods to determine proper height as well as comments from others who have already built a riser take a read through the following thread:
You should do a bit of analysis. Figure out where the bottom of the screen is, the size of your chairs and the size of people you think will sit in the back row. My room is almost 25' deep and I put in three rows. My screen is about 38" off the floor, and my risers are 8" tall and 5' deep and the back of the reclining chairs are about 42" tall. Everyone can see fine, except the back rows can only recline if the people in the row in front of them do.
There is a spec for stadium seating... I believe it's even a THX stadium seating spec... it's 12". Sorry I don't have the web site that has that spec, but it's out there.
I have a 9.5' ceiling in my HT, and with 12" riser, I can sit in the front row (6'2") and my buddy's wife (5' 4") can sit in the row behind me and my head doesn't block the picture. This is of course dependent upon how far back the 2nd row of seating is from the first row... but in the 2nd row you can comfortably stretch your legs out.
Take the difference between the bottom of the screen, and the tops of the first row occupants heads, and divide it by the distance from the screen to the center of the front seat occupants heads. This will give you the rise per inch measurement. Then measure the distance from the screen to the rear row eye position. Multiply this by the rise per inch, and you have how high the rear row eye level must be to view the screen. Subtract from that, the front row eye height, and you have your riser height. This is assuming your front row seats are the same as the rear row seats. You might also want to add a couple of inches, as this formula gives the bare minimum clearance.
I have 3 rows of seating and a 12 foot ceiling. Each row is 14" above the row in front of it (front row on the ground). We calculated for the second row being reclined and the front row being upright with no blocking of the picture.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!