Film-Tech Forum ARCHIVE: Speaker Suggestions for Auditoriums & Gyms

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Posted by Joshua Lott (Member # 240) on 03-18-2004, 12:22 PM:

I am looking for suggestions on speakers that would work well in theatres (used for plays) and gym's.

I have used and been very happy with Electro-Voice Cinema and Loudspeaker systems.

The set up will include a screen that is 45-60 feet wide. There will be about a 350 person capacity.

The current plans are to go with the typical left, center, right, sub, and surround setup.

Would the QRx153 series work good for the l,c,r?
I was thinking the SL10-2V or the SL12-2V for the surrounds.
And for the subs the TL880D was on my list.

Should I look at another type of speaker? I know JBL is popular, but I have had zero personal experience with them.

Something that I should mention is that this is for a portable setup. So the easier it is to move the better. But I will not sacrifice quality for a lighter or easier to move speaker.

Thanks in advance.

Posted by Gary Crawford (Member # 2038) on 03-18-2004, 01:18 PM:

Joshua, there are a lot of speakers and systems out there that will handle auditoriums just fine. Most are good, kind of like whether a Ford or Chevy is better.

The gym venue bothers me a little. Accoustics. They usually backslap noise so badly. Echoes echoes and more echoes. Ever watch a high school basketball game and try to make out what the announcer was saying? Almost impossible. True, a room full of bodies will absorb some sound, but I'm thinking bare block walls, polished wood floor, open steel truss ceiling, and all sorts of other audio hazards. You might have to hire someone to scope this out for you.

Posted by Joshua Lott (Member # 240) on 03-18-2004, 01:48 PM:

I am thinking of creating an "auditorium" inside the gym.

Think creating walls or half walls using fabric. Suggestions?

Posted by Scott Norwood (Member # 30) on 03-18-2004, 01:58 PM:

Depending on how bad the gym is, you might actually be better off running a high-quality mono setup (full-range with A/SR noise reduction, as appropriate). Most gyms are really bad acoustically and multi-channel systems are liable to make this worse. Mono can be made to sound very good, even though it usually doesn't in practice.

Do you really want a 60-foot wide screen for 350 seats? That sounds unusually large. I'd think that 25-30 feet might be more appropriate.

To answer the original question: I agree it's an issue of personal taste. The acoustics of the room and the tweaking of the system seem to make a huge difference, too. I've heard great-sounding systems that used anything from EV to JBL to Altec to other brands, and crappy systems that used all of those brands, too.

Posted by Joshua Lott (Member # 240) on 03-18-2004, 02:05 PM:

Scott,

I am trying to go "a little larger" then normal. But I do not want to over do it. Giving the audience something more to talk about. I am trying to keep the sound and picture professional, and I do not want it to look or sound like it is just thrown together.

I will be setting up in a local school gym before I fly to these locations for a "live" run.

The thought is to create an event. Something to keep them talking. Would a 40 foot wide screen be more to what I am looking for?

Would you say that dropping the surrounds in the gyms more appropiate and just running the 3 stages in mono? What about the sub?

I have no experience in set up's in gyms. What other things can I do to help with the acoustics?

Posted by Paul Mayer (Member # 355) on 03-18-2004, 03:54 PM:

Gyms are going to be a real problem. As has been mentioned, all those hard surfaces will produce multiple echos that will be hell on intelligibility.

If you're not going to use the entire space anyway, perhaps you can carry enough pipe and drape on the truck to section off and acoustically deaden your seating area. If you can dampen your space down, you should have a good shot at achieving decent stereo.

Stereo in such a live room tends to be a mess, again due to all the reflections. And multiple-speaker mono will generally be just as bad for the same reasons. For really live rooms it's usually best to go with as close to a single point source for your sound as possible. If you decide you're going to do this project in good mono, I'd recommend building just a single center stage speaker stack instead of the L, C, R three. That will noticeably improve intelligibility.

Posted by Matt Zeiner (Member # 1914) on 03-18-2004, 05:54 PM:

The problem of deadening the space with respect to high frequencies is easily solved as suggested, by drapes. Unfortunately the RT at lower frequecies will remain unaffected. I would definately keep it simple here - front-surround can sound very good in extremely live rooms. Forget about the sub - it will cause more problems than it will be worth. my 2 cents.

Posted by Kenneth Wuepper (Member # 1174) on 03-21-2004, 11:00 PM:

The Baseball Analogy:

By placing the Booth at home plate and the screen at second base, there are essentially no parallel and opposing surfaces in that room as you are using it. The highs can be reduced from bouncing off the walls between third base and home plate as well as home and first base.

Surrounds may be very effective in the two corners of the newly created space. (EG first and third bases)

The natural amplification of the corner speakers will reduce the amount of amplification needed. Only 2 surround sources could be very effective in that kind of space.

I am thinking that you want to make this a "Portable Cinema". This technique will make it possible to troup the least amount of equipment for the job.

Posted by David M. Dorn (Member # 2298) on 03-28-2004, 12:50 AM:

Check out the Frazier loudspeaker web site. They have a paper on loudspeakers for Gysms. The link to the web site is:
http://www.frazierspeakers.com/
The paper on Gym applications is in the Technical Doucuments section of their website.

Posted by Tony Bandiera Jr (Member # 2365) on 04-14-2004, 02:00 PM:

Joshua:
A suggestion that I've used for an outdoor show (40' screen and over 2,000 people) is to run the "Hearing Impaired" output from your cinema processor as your single stage channel. The Dolby CP-65, 500 and 650 have this output. It combines the l, c, and r signals so you don't lose any information. I flanked the screen with two speaker arrays outdoors, but you should place your speaker(s) centered. Try using two cabinets with the same feed placed as close together as possible and flared out at a slight angle.
Subs would probably not be a good idea....too much slap.
Screen size of 40-60' would require a 4kw Xenon...and three-phase power for the rectifier. A gain screen of 20-30' would work with a 2kw xenon and single phase power with a switching rectifier. That is the setup I use indoors.
Feel free to email me if you have any specific questions.

Posted by Frank Angel (Member # 248) on 04-17-2004, 06:14 AM:

I ran into this acoustical nightmare problem quite a number of years ago and did the usual cover-everything-in-site-with-24lb-velour method of echo abatement and when that didn't work, especially for the incredible booming low frequency resonance, we put in big sound absorbing cylinders made by rolling up 6in sound insulation sheets and stuffing them into fishnet "socks" and hung them in the corners and the back and side walls. Yet with all that, it remained quite a frightening space. Of particular freakishness were the bleachers which were constructed with hundreds of moveable metal parts, all of them mechanically joined in a rather loose fashion, causing them to vibrate with any low frequency sound below 300hz. They created a kind of metallically snare drum sound all their own that emanated from all around you like circle surround. Bodies helped, but not enough to make any difference (and of course, at the door, each patron was handed the special 24lb velour overcoats which they were required to wear).

And after all this treatment, and a myriad of different speaker placement schemes, speech intelligibility in the room remained....well, let's just say, there wasn't any speech intelligibility! You might as well have been running foreign films without benefit of subtitles.

Then there was that unusually high ambient noise level -- a kind of low frequency rumble -- that seemed rise just after some dialogue and fall when no dialogue was present. We finally traced that down: it was the constant murmur of 300, 400 people saying in a low tone under their breath, "What did he say?"...."What did she say?"

In the end we all agreed that about the only solution that made any sense in that venue was to just program foreign films (subtitled) and of course, all the great silent classics!

I might be exaggerating a bit, but not by much, Josh, not by much.