Sizing a PA for a Small Theater

Recording Techniques, People Skills, Gear, Recording Spaces, Computers, and DIY

Moderators: drumsound, tomb

Post Reply
drliebs
gettin' sounds
Posts: 109
Joined: Thu May 22, 2003 1:25 pm
Location: Ohio
Contact:

Sizing a PA for a Small Theater

Post by drliebs » Mon Apr 05, 2021 3:15 pm

I know this is the Creative Recording forum, but I'm sure there are folks out there with some experience with this sort of thing. :D

I am a studio engineer with limited live sound experience, just your local bar band kind of thing. A theater group I work with just got their own space, an old movie theater from the 1930's. It is a cool space and they are looking to me for help on choosing PA gear or at least getting a road map to the future planned out. The budget is thin to say the least.

The dimensions for the seating area are approximately 45' wide by 70' long. The ceiling is about 40' high in the first row, 32' at the back row.

Some of the performances will be rock bands and the desire is to have enough thump at a pretty good volume. I think 97 db 35' back would be my best guess.

What thoughts do you have? What kind of consideration do we need in regards to subs and speaker coverage? I'm sure there are a hundred things I don't know so any advice is welcome. We are starting out with a small budget and hope to improve along the way.
GT Room.gif
GT Room.gif (160.18 KiB) Viewed 2920 times
If it's not Scottish it's CRAP

User avatar
markjazzbassist
tinnitus
Posts: 1050
Joined: Mon Apr 25, 2011 11:33 am
Location: Cleveland

Re: Sizing a PA for a Small Theater

Post by markjazzbassist » Mon Apr 05, 2021 3:28 pm

where in ohio? i'm in cleveland. what is your dollar amount budget?

User avatar
Scodiddly
genitals didn't survive the freeze
Posts: 3955
Joined: Wed Dec 10, 2003 6:38 am
Location: Mundelein, IL, USA
Contact:

Re: Sizing a PA for a Small Theater

Post by Scodiddly » Mon Apr 05, 2021 6:18 pm

If you're doing rock shows then rent an appropriate PA for each show, and make it part of that show's budget. The tech rider for the band will quite often list what is needed. Seriously, don't buy anything unless you're doing shows every week.

The Scum
moves faders with mind
Posts: 2745
Joined: Thu Jul 03, 2003 11:26 pm
Location: Denver, CO
Contact:

Re: Sizing a PA for a Small Theater

Post by The Scum » Mon Apr 05, 2021 7:33 pm

A year into a pandemic might be a good time to go hunting for a large PA system.

I see a ballroom of similar size near me clearing out their system for peanuts, and a lot of bargains on
big PA stuff on CL. Nobody's played a gig in a year and want to get some value out of the gear.

to the OP:

Is the structure of the place solid enough that you can fly cabinets over the wings of the stage? Or will they have to be stacked? And can you squeeze subs under the front lip of the stage?
The tech rider for the band will quite often list what is needed.
I rember seeing Firehose's tech rider in 92 or 93. My recollection was that the spec was 1000 W to FOH for every 50 people in venue capacity.
"What fer?"
"Cat fur, to make kitten britches."

drliebs
gettin' sounds
Posts: 109
Joined: Thu May 22, 2003 1:25 pm
Location: Ohio
Contact:

Re: Sizing a PA for a Small Theater

Post by drliebs » Tue Apr 06, 2021 10:00 am

markjazzbassist, we are in Chardon.

As for budget, I am trying to push for buying a pair of substantial subs. For now, we have to use the mix of existing gear we currently have.
2 EV SX500
2 Mackie SR1530's
2 RCF NX 32-A

We plan on mounting these in the walls on either side of the stage. We can vary the angle to try to distribute the sound.
Here is a picture

You can see the existing 2 speakers, we plan on putting the others below. The entire area from green to the curtains on the side wall is easily accessible plywood facade. We could put the subs under the stage, but we were thinking of putting them stage level to the side of the other speakers.

I'm not sure yet how the stage will effect the sound of the subs. We are looking at a pair of these Mackie SR18S 18-inch 1600-watt

I have reservations on if this will be enough. It may have to do for a while. Renting is always an option, we may have to consider that if we get an act that needs more.

The structure is substantial enough to mount a hanging rig, maybe down the road this could be upgraded. We will see what we can find in the used department, that is a good suggestion.
If it's not Scottish it's CRAP

dave watkins
suffering 'studio suck'
Posts: 410
Joined: Sun Jan 13, 2008 3:25 pm
Location: Richmond VA
Contact:

Re: Sizing a PA for a Small Theater

Post by dave watkins » Tue Apr 06, 2021 11:10 am

That space is not gigantic so you may be able to get away with using what you've got as a basic rig for day to day theatre music, cues/sfx, and public address uses and then upgrading when the money is there. Hiring a PA when you have a bigger concert situation is definintely a good solution in the meantime. That would also give you the ability to see/hear how different systems work in the space without having to commit to a big purchase up front, and then maybe you can maneuver to purchase and install a system featuring whatever gear worked optimally. Some rental houses are also do A/V install work so you might be able to get a relationship going that would be beneficial if you end up installing a bigger sytem down the line. If the theatre company plans to do a lot of musicals with live music, Then yeah you should be looking at getting a bigger system installed sooner.

Honestly I'd probably just try and get a day to yourself with the gear on hand, set things up and listen to music you are familiar with in the space and see what different placement options do for the sound in house. You'll know pretty quickly if the speakers are struggling. Pairing the SR1530's with subs and doing a ground stack near the proscenium for now would probably work fine, crossing them over so they aren't trying to reproduce the lowest fequencies, and leaving the subs to do that should get you more clean headroom and fill the space fine for most things. The existing speakers look like they are installed in the wall? if you are going to use those in conjuntion with other stuff sitting on the ground in front just be careful of phase cancellation since they'd be offset from eachother. Would be best to have the drivers in vertical allignment. My one concern with speakers in that location long term is feedback if you do anything with lots of mics.

Long term though if I were upgrading a space like that to handle live music and theatre, it would be good to get speakers flown, maybe a smal line array closer to the audience at the edge of the stage, and maybe have the subs sit in the house just in front of the stage. There's so much stage in front of the porscenium, that you won't be doing yourself any favors in a live music situation as far as feedback is concerned with the main speakers/subs are back there behind performers.
the tape is rolling, the ones and zeros are... um... ones and zeroing.
http://www.davewatkinsmusic.com

User avatar
Mach 1
audio school graduate
Posts: 17
Joined: Mon Jul 19, 2021 11:23 am

Re: Sizing a PA for a Small Theater

Post by Mach 1 » Tue Jul 20, 2021 12:01 pm

Hi,

To save a lot and not make compromises on sound quality you may want to look into older PA equipment which provides high quality, reliability and recognition though the years.

PA for your room and your applications:

- A pair of EAW KF-650i or KF-850EF (3-way system) flown as high as possible, near side walls, toe in; as these are point source 60°x40° dispersion
- 2x or 4x SB-600 or SB-850 subwoofers to handle the subwoofer duties; as subwoofer quantity really depends on the room total volume
- Crest 4801, 7001, 8001 amplifiers and MX-800 analog processor

note: KF-650i and KF-850EF earlier version use RCF speakers which are premium components and better version than later KF-650Z and KF-850Z

Alternative

- 4x or 6x L Acoustics dVDOSC per side flown as high as possible with 4x dVSUB bass (which utilize 3x 15" drivers each) as line array system
- 2x L Acoustics ARCS per side and 2x SB-28 subwoofers
- Lab Gruppen FP-4000 or FP-6000 amplifiers and BSS Audio FDS-366 digital processor

Stage monitors:
- EAW SM-400 with 12" and 2" compression drivers
- L Acoustics EX-112 co-axial 12" and 2" compression drivers
- 2" compression drivers is a must for monitors for both vocal clarity and reliability with feedback (avoiding burning voice coil)
- 4 or 6 or 7 stage monitors plus 1 for PFL (listening at monitor position)
- Rarely seen but side fills flown high near main PA can provide wide coverage of stage for main vocal and much less prone to feedback issues

Console

Sure a digital console is a trend these days with Yamaha, Digico, Digidesign, Midas Pro and Soundcraft for FOH (front of house). The learning curve may be steep, looking at a screen and scrolling through menus slow down and distract from looking at the stage where a lot can happen and require immediate reaction in mixing (10 fingers on faders) and sorting out corrective EQ quickly from one sound to the next.

Now a Midas XL-200 analog console could be quite nice with minimum outboard for a permanent installation. Easy to use and great sonics. These can be found for a small budget these days on used market. Very reliable without any computer related issue and zero latency. Much faster to use with 1 function per knob and friendly layout interface. Anybody can jump on an XL-200 and get a decent mix quickly with a 15 minutes soundcheck.

Outboard:
- 2x or 4x Drawmer DL-241 or BSS Audio DPR-402 compressors
- 2x dbx 160XT
- 1x Lexicon PCM-80
- 1x Yamaha SPX-990
- 2x TC Electronic D2 delay
- 1x channel strip for main vocal could be a nice addition later especially with a great vocal mic like a Neumann KMS-105

Crest XRM-24 analog console could be added as a companion to the FOH position for stage monitors duty with simple to use yet effective mixing.

Room acoustics:
- room back wall acoustic treatment with 2" glass fiber or Sonex melamine with fire rated fabric covering or perforated wood panels in order to suppress the back slap echo noticeable from stage and room
- acoustic treatment on stage (ceiling and side walls) can avoid also excessive reverberance and flutter echoes ... reducing sound level on stage and improve greatly overall clarity and better capture of sound with stage microphones
- low profile acoustic gobos can be nice addition for back of amplifiers absorption (leakage reduction)
- several carpets can be nice for drum set, keabord or percussion area and main singer

Stage:
- quality cables (Belden or Canare) with quality Neutrik connectors well hand made with quality soldering and shrink tube
- distribution boxes 8 channels with multipaire cable (Belden or Canare) with snake
- quality microphones stands from K&M with tripod feet (standard size, small size and 1x or 2x pair of extra tall stands for stereo pair OH)
- many quad power strip for stage power distribution
- power supply for effect pedals can save the show (instead of running on batteries)
- accessories: drum sticks, guitar picks, extra 1/4" instrument cable, quality DI box BSS AR-116 and at least one tuner and extra drum key
- partition holders with Littlite

Tools:
- Fluke 107 multi-meter and a Weller soldering station can save the day along with small tool inventory to open any rack unit
Last edited by Mach 1 on Thu Jul 22, 2021 11:57 am, edited 5 times in total.

User avatar
Scodiddly
genitals didn't survive the freeze
Posts: 3955
Joined: Wed Dec 10, 2003 6:38 am
Location: Mundelein, IL, USA
Contact:

Re: Sizing a PA for a Small Theater

Post by Scodiddly » Thu Jul 22, 2021 5:36 am

Old analog consoles are only a good deal if you are a tech who likes repairing them.

There was a period of time when guest engineers would appreciate an analog, but I think those days are now gone.

Post Reply

Who is online

Users browsing this forum: Google [Bot] and 31 guests