Film-Tech Forum ARCHIVE: Speaker placement in large auditorium

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Posted by John Hegel (Member # 628) on 03-13-2004, 10:43 PM:

I am looking at the possibility of opening a movie theater in this auditorium, and was wondering if I can reuse any of the old sound system for either surround speakers or stage speakers.

Currently installed in the building as a "house system" is:

Stage right speaker stack (stage left stack is identical)
Altec MR II 564/299-16 (aimed at balcony)
Altec MR II 594/299-16 (aimed at main floor)
Altec 8127
Altec 8156

Under the balcony 8 feet in from the edge are (5) Altec M-100T

Amps:
Altec 9442
Altec 9444
Also a QSC that is not listed on the information I have at this time.

The main house speakers are recessed into the walls on both sides of the stage at mid-way between the floor and ceiling.

(Sorry about the pictures, the B&W ones are the best I have of the whole facility)

Can these mains be used for anything in their current place for a cinema?

Thanks for your help

Posted by John Pytlak (Member # 331) on 03-15-2004, 09:46 AM:

You really want to place those main speakers BEHIND the screen.

http://www.jblpro.com/pub/cinema/cinedsgn.pdf

JBL Cinema Sound System Manual

Posted by David Favel (Member # 1125) on 03-15-2004, 05:17 PM:

I have pretty much the same set up. There were some unique adjustments done during the initial EQ, with L/R at the side & centre behind the screen.
Get friendly with your tech.

Posted by John Hegel (Member # 628) on 03-15-2004, 10:43 PM:

Thanks for the information

Could they be used as a surround channel of any sort?

Posted by Kenneth Wuepper (Member # 1174) on 03-16-2004, 06:48 AM:

John,

I am excited for your project. That is a great hall for the presentation of film. I have done some work in such spaces and may offer some suggestions.

With regard to the present "sound reinforcement system", the main speakers on either side of the stage: Are these separately amplified? That is, are the right and left speakers totally independant? Can they be made so?

The speakers along the front of the balcony are for "fill" to the area under the balcony. These are on a delay so that their sound synchronizes with the sounds from the main speakers beside the stage.

The picture does not indicate the location of the screen as far as upstage from the grand curtain. How far is the screen upstage? What space remains behind the screen? The BIGGIE! Is this a perforated sound screen?

If you can supply some of these details I can assist you further.

KEN

Posted by John Hegel (Member # 628) on 03-16-2004, 10:50 PM:

Thanks Ken

The speakers on either side of the stage are currently setup as mono. It would take little effort to change it to two channels since they are already tri-amped, however, I would have to change the crossover setup.

The screen that is currently in the building; I fell will be inadequate for the experience I want to offer, so I am going to install a new perf. screen. I plan on hanging it on the second fly behind the first (cant think of proper term) short black curtain, which will also double as the top masking. Being on the second fly the screen will be about 5 feet from the grand curtain.

I'm also planning on flying the stage speakers on the 3rd or 4th fly, so that if the situation calls for the use of the stage I can just drop and go. Being that the stage speakers will be in the air when the stage is in use I would like to keep the current house speakers in there location so that I can have sound, and also would be nice for the non-sync when the curtain is closed.

Behind the screen I would guess there is a good 20 feet to the wall, but there are 3 more sets of curtains before that wall. I'm assuming it would be best if I keep all of them closed during a film.

I hope that helps and sort of makes sense

Posted by William Hooper (Member # 71) on 03-17-2004, 12:34 AM:

The short black curtain is called a border or teaser.
It usually hangs right in front of & functions to conceal an "electric", a pipe batten hung with lights. 1st border would be right in front of the first electric, which sound about like what you're talking about since you say it will be about 5' upstage of the grand.

So where will the electric go? In front or behind the screen; if in front, ready to snag & melt the screen, if in back, no longer well concealed by the teaser. You need your top masking hanging on the screen frame for umpty reasons, not the least of which is that scalloped edge will drive you & everyone else up the wall.

There was some previous discussion of a situation like this here, located in Yak, where the evil moderators consign any topic which dwells lengthily on cartouches or urns.

Posted by John Hegel (Member # 628) on 03-17-2004, 01:44 AM:

Now that I look at it more closely I agree with your concerns about the screen placement and it interfeiring with other things.

The proc. opening is 61 feet, if I installed a screen to match or nearly match that would it look weird to set the screen at mid stage?

If push came to shove I could remove some of the stuff that is in the air back stage.

In my opinion it is better to have this building standing with some lights missing then not standing at all.

I'll take some pictures of the back stage tomorrow to give everyone a better understanding of what I have to work with.

Posted by Kenneth Wuepper (Member # 1174) on 03-17-2004, 07:00 AM:

John,

You mention having the stage configured for cinema is the alternative to destroying the structure? What are you trying to do here? Is this a functioning building or one that is no longer used?

The hang in our big theatre looks like this:
Proscenium:
Fire Curtain
Grand Teaser
Grand Traveler
Blank Batten
First Electric A
First Electric B
Border Lights 1
Black Teaser
Motorized Traveler (Remotely Controlled)
Hurley Super-Glo Screen (23 x 46.5) with attached moving masking

This is the first 8 feet from the fire curtain and the stage is 36 feet deep with 50 line sets on counterweights.

Posted by John Hegel (Member # 628) on 03-17-2004, 02:56 PM:

This building is no longer in use, but still in excellent condition. It has been empty for 4 years and the last two without heat.

The whole property is in danger of reaching it demise through actions of city government due to other areas of the property are becoming eye sores. They have started taking actions to remove an area of the property, and was suggested by them that if they have to pay to remove anything that they are going to level the whole property.

Off the record they said that if any area was being used by the public or a business they would back off and leave it alone, but that doesn’t sit well since I’m one of the few people that has looked into its use in the last 4 years.

Posted by Kenneth Wuepper (Member # 1174) on 03-17-2004, 03:53 PM:

I am leaving for Buffalo NY tomorrow and will be back Monday. If you don't see any more posts it's because I am away not disinterested.

There may be many more issues in that property than the placement of screen and speakers. Was the property properly mothballed? How is the roof? What fire code issues are you aware of?
KEN

Posted by John Hegel (Member # 628) on 03-17-2004, 10:22 PM:

The entire structure has had the water lines drained and blown out along with anti-freeze in the drains. I'm sure they have missed a drain or two in the building but that in itself should not effect me.

The roof is a rubber membrane with 3" foam under it and rock on top. I was told by the former grounds keeper that it is the newest roof in the building and was installed in 97 or 98. From a visual inspection it looks good to me as well and appears not have no leaks. From the catwalks above the seating it looks like when they put the new roof on they also ran new PVC drain lines.

I had the city fire inspectors look at it about a month ago and the only concern they had was for me to have a professional look over the sprinkler system and add a drop above the future concession stand if serve popcorn and other hot foods. If I do use the kitchen below the auditorium they want me to replace the exhaust extinguisher with a more modern (co2?) system; but I do not plan on using it in my first years.

Some personal concerns I have: does anyone know about how much it costs to maintain an elevator or two for that matter?

The lighting system (colortran) is new as of 1995 and works now, but with my luck it will be the first thing to stop working.

The lobby walls and floor are marble or some other stone that looks like marble. It is in excellent condition, but with constant use should I be concerned about maintaining it? Also the safety of people walking on it when wet, from personal experience it tends to be slippery.

Posted by William Hooper (Member # 71) on 03-18-2004, 02:42 AM:

For such a wide proscenium opening, what will likely determine the width of the screen is the available height. The width of the largest unmasked screen area will be scope, 2.4 times the height. So if you've got 25 feet of available height from the floor to a good spot with a little room for top masking, it will be 25' wide * 2.4 = 60' wide. In that theater, it seems like what will determine the height will actually be the height which can be seen from the last row of the seats under the balcony without cutoff by the balcony, which may be less. If it's 20', then 20' * 2.4 = 48' wide.

At 60' wide, that's a large, expensive bulb & lamphouse. Big picture, & a big house. A barn! And wide, you'd need a matte screen (rubbing the bottle to produce John Pytlak) & a 7k bulb.

quote:
If push came to shove I could remove some of the stuff that is in the air back stage.

You should be careful in design & make sure that the screen installation does not in any way interfere with the use of the stage equipment for stage shows: bus & trucks, bands, etc. Get a college stage tech textbook to find out what it's all for & how it works. A theater is a machine, & all those doodads do something. It would also be a good idea to get a book on law for public assembly businesses.

You will be in the business of putting butts in the seats, & filling that huge place with just movies likely wouldn't be as practical an idea as maintaining it as a performing arts center for the other uses above. You need to have as many shows as you can. You'll want to do rentals for everything you can think of: rock shows, dances & balls, movies, video shoots, etc. You'll have to consider how other venues around the area are positioned & marketed, & work from there to attract that business & possibly be a venue which can offer other features. If the symphony or touring shows hit another fancy venue nearby, you may need to remove the seats from the orchestra & become the Fillmore.

The acoustics look like they could be good in that theater, depending on the wall covering, but sheesh it's huge! How many seats?

quote:
The lighting system (colortran) is new as of 1995 and works now, but with my luck it will be the first thing to stop working.

Wow, huge expensive thing already in place.

quote:
The lobby walls and floor are marble or some other stone that looks like marble. It is in excellent condition, but with constant use should I be concerned about maintaining it?

The walls could be scagliola, which is painted art that looks like marble. You don't see a whole lot of scagliola any more, since the labor of producing it may now be more costly than just buying marble. The floors could be marble, but it's not a very standard floor covering except for stair treads, etc. because it's expensive, porous, & stains easily. Could the floors be terrazzo (stone aggregate set in concrete during construction & the whole thing polished flat & shiny)? Terrazzo you just wash, & wax if you want.

Posted by John Hegel (Member # 628) on 03-18-2004, 12:26 PM:

I'll look into those books, they should be helpful in other aspects of managing this theater as well.

When it was built it had 2022 seats, but is said to now have 1850; I will take time one of these days and count them.

You are right about the acoustics. I have never seen a live performance in this building, but after talking to the past director of events she said that everyone professional or not admires the acoustics. She also said that some of the great singers that have walked the stage claim its the best they have ever seen.

quote:
Wow, huge expensive thing already in place.

That’s what I though. It has 160 dimmers for that stage.... doesn’t that seem like a lot?

The lobby is a cut stone of some sort. Hear are a few pics of it, maybe someone might know what it is.

Posted by William Hooper (Member # 71) on 03-19-2004, 03:54 AM:

quote:
I have never seen a live performance in this building, but after talking to the past director of events she said that everyone professional or not admires the acoustics.

There's a sort of maxim that a theater with great acoustics for unreinforced (i.e., acoustic, no amps) sound can be pretty bad for shows which use amps & speakers, & vice versa. The old silent movie 'palaces' were built for excellent acoustics with orchestras, organs, etc., but when talkies arrived, they were FAR too bangy & had to have absorptive material & devices stuck everywhere possible: ceilings, walls, etc. With the arrival of pink noise, rta's & better eq, those houses can now sound pretty good, but as an example THX is having to make them a special category because it's hard for them to hit the THX specs.

quote:
That’s what I though. It has 160 dimmers for that stage.... doesn’t that seem like a lot?

You never have enough lights or circuits.

quote:
The lobby is a cut stone of some sort. Hear are a few pics of it, maybe someone might know what it is.

Is it outside? If so, it wouldn't be scagliola. The curved areas would generally mean it wasn't marble since that's a lot of expense & waste, but if it's something like a municipal structure, they tended to get hornswoggled into spending HUGE amounts of money for things like real marble when commercial structures used materials which only looked like marble. It could be some later synthetic material; when was it built?

Posted by John Hegel (Member # 628) on 03-19-2004, 10:01 PM:

Construction of this auditorium was started in 1937 and opened to the public in 1940.

It is in fact a building that was paid for by the tax payers, but is now in the hands of a private owner.

Posted by John Hegel (Member # 628) on 07-19-2004, 03:07 AM:

Bringing up this topic again...

Has anyone had any luck with placing the suround speakers in the ceiling (in my case 37 feet in the air?

I would rather not have any on the speakers within sight of a person seated in the room.

Could it be done in such a way that 2 smaller stage type speakers placed in the ceiling would be able to fill/cover the pit and front of the balcony. Then for reinforcment place the normal amount of speakers along the back walls of the balcony and floor seating?

This is just an idea I am playing with, but would like to have other peoples input.

Posted by John Pytlak (Member # 331) on 07-19-2004, 02:18 PM:

quote: John Hegel
Has anyone had any luck with placing the suround speakers in the ceiling (in my case 37 feet in the air?

I personally would avoid attending any theatre using such a non-standard placement of the normal surround channels.

On the other hand, if it was a sound mix taking advantage of additional channels to provide a "Voice of God" channel above. [Cool]

Posted by Steve Guttag (Member # 268) on 07-19-2004, 05:03 PM:

Yes, I have had success in placing speakers high up in a theatre (technically in the ceiling).

However, I would avoid it.

In my application, the customer wanted invisible speakers since the room itself was to be devoid of such technical features (it is Colonial Williamsburg). There were two "slots" in the ceiling where lighting instruments lived and the slots spanned the width of the room (note, these slots were not orginal to the room). I was "allowed" to place surround speakers up there so long as they did not hang below the ceiling line.

I placed four high-power surrounds up there. I was also allowed to place some surrounds in the faux balconies. Using some modeling to define the coverage and placement (EASE software) and then some use of delays to time align the rear speakers to the ceiling speakers, I was able to obtain a uniform coverage where the rear speakers help pull the sound down some. The customer was quite pleased.

If you ever venture to Colonial Williamsburg, VA, check out the Kimball theatre.

Steve

Posted by Gordon McLeod (Member # 33) on 07-19-2004, 05:19 PM:

Phillips in there publication "designing the Cinema recomended ceiling mounted surround speakers