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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => Installed Sound/Contracting FUD Forum Archive => Topic started by: Dan Cascino on July 14, 2006, 08:49:31 pm

Title: single versus two speakers in a small room
Post by: Dan Cascino on July 14, 2006, 08:49:31 pm
Just looking for some insight... We have a school hall where the installed sound reinforcment is a toa mx401 and a single ramsa (yes ramsa) ws200. originally installed in 1992...I have the reciept. The speaker was damaged and we are taking this oportunity to upgrade the system.. I was considering puting 2 speakers in the hall.. the hall is 30'wide 60' long and 12' cieling,with a shoebox stage on one of the long ends... is there any advantage having two speakers, one in the upper left and right corner of the room on the stage side facing the audience versus a single speaker? how does two spoeakers effect spl over distance. I was considering using community mvpII 15's in this room, or should I combine my assets and buy a single more powerful speaker...maybe a JBL or EV
Title: Re: single versus two speakers in a small room
Post by: Duane Massey on July 15, 2006, 12:11:59 am
I would look for a cabinet with a narrow pattern, but realize that you should take into account the available power from your amp may make 2 speakers a bad idea. Community, EAW, etc, all have boxes with 60x40 or similar horns, and there may be other better choices as well.
EAW has a 2-way box that comes with a 90x40 and a 60x35 that is ready to fly (VR12 or VR15), and is reasonably priced.
Title: Re: single versus two speakers in a small room
Post by: Tom Young on July 15, 2006, 07:03:42 am
It is always the case that the fewer the loudspeakers the better.

Having 2 versus one does nothing for SPL over distance. It does increase SPL (to all seats, all distances) but mostly at lower frequencies.

How well a loudspeaker covers (how even the coverage is) depends as much on position/height as anything else. One loudspeaker could cover this area with fairly even SPL if it is high enough.

These are generalizations that can be used as guidelines. But the real deal depends on the dimensions and geometry and shaping of your space.
Title: Re: single versus two speakers in a small room
Post by: Brad Weber on July 15, 2006, 10:04:02 am
Just to add to Duane and Tom's excellent points, if your sources are primarily mono, such as speech, a single speaker (or cluster) is best.  Having multiple speaker locations can cause numerous problems due to interaction between the speakers.

60' long with a 12' ceiling, you may have trouble getting good coverage of the entire floor from just a speaker or speakers the front of the room while still keeping reasonable gain before feedback for a mic on the stage.  It would be a much bigger change but to get good coverage for the entire audience area you may want to consider some delayed fill for the back part of the room.
Title: Re: single versus two speakers in a small room
Post by: Dan Cascino on July 17, 2006, 04:19:32 pm
Since the original post a few things have changed. This room is an L shaped room, made up of two rooms with a movable wall/ door separating them. (See diagram jpeg). The second room is 30x30 roughly. Now they want a speaker or speakers in there as well. So I am considering replacing the toa mixer with a Yamaha either emx312 or emx512.. I am sure your wondering why?  Well we have a blackbox where the toa lives that defines my physical amplifier size, the Toa is only 4 channels in , I will be adding some condenser hanging mics for the stage (permanent install) so these and the other inputs needed  require that I have more available Ins.  I have listened to Mackie, Peevy, Sound tech, Carvin, Yamaha and ever Behringer (don’t wince) and for the price, size and performance the Yamaha seems fairly decent. Then there is the speakers, mounts and cables which we have briefly touched on.. But here is the bottom line …about 1800.00. Not much, typical for a catholic school. So I am trying to give the best their catholic dollars can afford.. Not to mention that I want to set it up, close the cabinet, lock it and put an on/off switch on the outside so that very few can mess with it.. Otherwise I ( a school parent) will be called all the time to fix a problem that will probably be caused by too many hands and too many knobs. After looking at the higher end EAWs and Community’s they may be out of reach, time to revisit. Will probably not be able to swing delayed fills, would be nice, but more equipment in the box being operated by teachers and 8th graders. Bad Mix. Sorry for the length.
Dan Cascino
Title: Re: single versus two speakers in a small room
Post by: Brad Weber on July 17, 2006, 05:49:21 pm
With those dimensions, a 12' ceiling, a divide/combine scenario and a limited budget I would seriously consider a distributed speaker system.  Not necessarily ideal but getting good coverage and intelligibility in that space without multiple speakers or something like a steerable array ($$$) will be difficult no matter what.  With the budget and room you have to work with having localization to the stage may have to be sacrificed, any fills and whatever covers the wing of the 'L' would have to be delayed to keep any localization and that's probably not practical.

If you had the budget something like a Biamp Nexia PM or Symetrix SymNet Express with their controllers moutned accessible to users might be a good solution.  Would let you control what users can access while still allowing for overall volume control, input level control and even the room combining if desired.

By the way, delays would normally not be something the users would interface with.  Those are set and locked away from prying fingers.
Title: Re: single versus two speakers in a small room
Post by: Dan Cascino on July 17, 2006, 08:46:45 pm
thanks for the response, what type of distributed system should I research, or if I could find a small delay unit to run the speakers in the second room considering both size and costrestraints, I could probably bury that in the black box. figuring on 1000$ for speakers for both rooms what recomondations anyone might have, for me to take a look at, once again either two single or two twin speaker configuration?
I thank you for the insights...
Dan Cascino
Title: Re: single versus two speakers in a small room
Post by: Ivan Beaver on July 17, 2006, 09:13:46 pm
A couple of questions.  Is your $1000 figure retail or dealer?  Does this figure include installation?

As Brad said a distributed system may be your best way due to the low ceiling.  You will also get typically get greater gain before feedback with a distributed system.

The quality can be very good with a distributed system-IF you use quality loudspeakers (I really like the Atlas FAP42T-for cost and performance) and enough of them.

Depending on the layout you want/can use and performance/budget, you will need between 6 to 8 for the main room and 4-5 for the smaller room.

This should fit in your budget-assuming no cost for installation.