How do real theaters setup their surround speakers in the walls? I belive they mostly use direct radiators?

Another question is;
When you sit in the middle or backrow, why does it still sound "Correct" when there are speakers in front of you that are also playing the same information as ones behind you?

The big 16 screen multiplex here has there surrounds surface mounted on the wall. Be it there are a ton of them, but they arent in the walls here.

direct radiators? how do they get them to sound correct? I'm wondering why they use direct radiators Vs. Bi-pole/di-pole???

That I have no idea..hahah. Maybe because there are so many of them??

They use large arrays wrapped around the sides and rears, of many speakers, usually direct radiating. They don't use dipole bipole because it's a silly choice. Dipole/bipoles attempt to create a more diffuse source for the home where large arrays of a dozen or more surround speakers is not feasible. In the theater, using so many speakers creates such a diffuse surround envelopment. And, as to the OP's question, that's why it still sounds 'correct' despite the fact that there are so many speakers involved, many of which may well be in front of your listening position.

Hmm, you'll find JBL surrounds in a large percentage of theaters.

http://www.jblpro.com/pages/cinema/surround.htm

General rule of thumb is to position the speakers 2/3rds of the way up the wall and have them directed towards the far side seating. Depending on theater size, you will normally end with 3 or 4 speakers per wall. The rear wall is normally divided in 2, (ie 4 speakers, 2 would be part of the left, 2 the right) For Dolby EX tracks, the rear speakers are rewired into a dedicated channel. I was going to link to the Doldby DA20, but its not made any more......Anyways, with the Dolby EX tracks, the hardware is actually wired for 2 more channels, but only one is currently used if I recall correctly.

so, do you think I could build direct radiators and implement them in my theater the same way real movie theaters do? and would it sound "Right" with only having 2 rows?

1 set right behind the first front row 6 feet up the wall firing directly across the room at each other.

and another set right behind the rear row doing the same thing?

Would it sound "Proper" or intriduce some undesireable sound characteristic?

so, do you think I could build direct radiators and implement them in my theater the same way real movie theaters do? and would it sound "Right" with only having 2 rows?

1 set right behind the first front row 6 feet up the wall firing directly across the room at each other.

and another set right behind the rear row doing the same thing?

Would it sound "Proper" or introduce some undesirable sound characteristic?

If you have enough cubic feet in your room and more then 2 stepped risers, ( http://www.designcinema.com/galleries.html )then dual surround rows would not be a problem. Dolby suggests in a 7.1 design the you use two monopoles, (direct radiating) cabinets faced toward each other along with two rear mounted monopoles. If you choose other then monopoles, try tripoles, not bipoles and not dipoles.

I know Dolby says monopoles but they only show 1 row of seats in their diagram???

anybody have any diagrams showing a way for 7.1 with 2 rows?

Optimized for rear row.

Rob

do you have the L/R side speakers firing just behind the rear row listeners? how dose it sound in the front row?

Thanks,
John

Left and right rear speakers are placed to the sides of rear row. This is where I spend my time.