Film-Tech Forum ARCHIVE: Theater Sound Design

This is topic Theater Sound Design in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Michael Voiland (Member # 5386) on 12-11-2009, 11:40 PM:

When laying out sound for a theater how do you determine coverage. Normally the center would cover the entire audience what about left and right. I am mainly talking about horn patterns and what not.

Posted by Demetris Thoupis (Member # 833) on 12-12-2009, 06:08 AM:

If you really want to see coverage, there is a very good program called EASE that replicates all speaker dispersion, coverage e.t.c on the computer so you can determine models e.t.c based on architecture. The standard would be that you should point all screen horns towards 2/3 back centre listenining position of the auditorium. The most versatile speakers who have THE adjustments for these requirements are of course QSC.
Demetris

Posted by Michael Voiland (Member # 5386) on 12-12-2009, 02:31 PM:

Ease is quite expensive. I know how to do those calculations by hand I just and trying to figure out where does sound from the left speaker need to end up and the right speaker and center speaker. That is my issue. Does the horn pattern cover straight forwards and hit everyone in front of it and the middle section. Or does it cover everyone from the left corner.

QSC is nice. Community is also nice.

Posted by Cameron Glendinning (Member # 3516) on 12-12-2009, 05:46 PM:

Most cinemas use the 90x40 style of horn, curtain walled or acoustic treated auditoriums negate the need for too much thought. But if you have a long thin auditorium or a room with no acoustic treatment care should be taken to pick a horn with a tighter pattern like 60x40.
Careful installation and placement of the horn is vital for best results. The speakers should be mounted high, 2/3 up the screen and the horns should be pointed downwards towards the centre of the seating, left and right should be tapped inwards to also aim towards the middle of the room.
I would also suggest wings for speakers and acoustic treatment for your backstage for exceptional results.

Posted by Michael Voiland (Member # 5386) on 12-12-2009, 06:06 PM:

I work at a 9plex 5 of the 9 screens are drywall screens.... they took one theater when they took over and chopped it down the middle. Whoever did the work their took a single 15 with a top mounted horn and put it up on chains turned sideways. As you can imagine the results are less than impressive. And 2012 does not like the cross over in the speaker.

Posted by Richard Hamilton (Member # 321) on 12-12-2009, 07:39 PM:

Michael, what do you mean

quote: Michael Voiland
5 of the 9 screens are drywall screens....

Ive never seen a multiplex with no screens.

Posted by Marin Zorica (Member # 1716) on 12-13-2009, 07:14 AM:

Michael, all speakers are mentioned to cover whole auditorium, so left channel should cover also whole auditorium that all people can hear left, the same thing is with center, right, surround and so, normally is most easy do cover all with center, left and right is bit bed with long cinemas and so.....but if you follow the 2/3 rule you'll be on right point, even for wider cinemas I would rather put speakers bit further to end of screen, and when situation is bad like long and tinyer I would get them a bit away from end because is better to get spome good places o hear good sound, than all bad....

Posted by Sean McKinnon (Member # 612) on 12-13-2009, 12:57 PM:

quote: Richard Hamilton
Ive never seen a multiplex with no screens.

Unfortunately I can say that I have... I once (re) installed a theatre down on the cape in Mass that was closed and then expanded from 6 to 10 screens (with an all ORC package including ORC era Century's). The four small houses just had a concrete wall painted whiye with one speaker bolted to the wall below the screen. [puke]

Posted by Michael Voiland (Member # 5386) on 12-15-2009, 01:26 AM:

The building was a general cinemas 6 plex. 1 Theater became the kitchen. They took down the screen and masking in the largest theater. Then built a wall smack in the middle of the thing. Next thing you know they put up 2 Drywall walls where the screen used to be painted them and tried to make it look nice. No masking by the way. Its kind of a cool place to be but the sound sucks. They took the single 15s with the horns in that theater and turned them sideways hanging from the ceiling above the screen. I don't care what anyone says center / surround does not compare to left + center + right + surround.

Thanks for the help by the way it will make it a lot easier to figure out the best way to tackle these sound issues and work towards a better system.