Woohoo! Auditorium surround sound... help??

So, we have a cluster just above the stage. Two horns and a main in between. Nice system, but there are too many limitations. Also, the first two rows and the stage don't hear very well. Stage will have to deal with it, they don't really have to, but the sound travels clear over the first two rows. What I'm looking to do is hang two speakers left and right of the cluster, on the side of the stage like so:


Also, there's an I beam that I want to use in order to get a sort of surround-sound effect, behind the first section of seats (over a walkway in front of the balcony-ish area) facing the stage, but angled left and right crossing the audience:


There is a third I beam that I hung speakers on earlier tonight for the upcoming show, but the speakers aren't that great. This last beam is behind the balcony audience, once again crossing them left and right, exactly the same formation as the above I beam.

The auditorium seats above three hundred people, I believe. I could very well be wrong, and if a specific number is necessary/size is necessary for a recommendation, I can find that out tomorrow. Basically, I was wondering if anybody could recommend good speakers for the L and R stage speakers and the four speakers behind the audience? We're keeping the cluster and adding a subwoofer (likely a 500 watt Samson or a 300 watt JBL) directly underneath the front of the stage. Any recommendations are VERY MUCH appreciated. Thanks!



Well-Known Member

A full description with dimensions would help in formulating a recommendation.

Using multiple speakers from multiple locations is a problem waiting to be created. You'll experience combing, time delay and cancellation issues.

Today we installed a center cluster just over the downstage edge of a church stage, the seating area in front of the cluster is 50' deep and 80' wide and the trim height of the cluster is 28'. Using three EV FRI 152/94+ cabinets driven with an RMX 5050 at 2 Ohms feeds the cabinets 2500 watts. We are getting 116 dB across the 4000 sq.ft. with less than a 5 dB drop off in the far corners. Our Lara software shows no combing, cancellation or time delay issues.


Assuming you are only using this setup for a surround sound "effect" rather then true 5.1, you will be needing far more then speakers. Besides the necessary basics, your outboard choices will have to take in to consideration phase cancellation, time alignment, and crossover points, and depending on how you want it set up, a dsp matrix mixer. The image I have for a typical house with only 414 seats and a balcony would be a nightmare acoustically and would most likely ruin any type of surround effect you could hope for. Should you still be interested, I would recommend an Ashley 24.24M, with a Qsc Isa 450 into a set of JBL Control 28's. My suggestion... Front fills. I'd use a pair of Stage Accompany F7's. Not nearly as much work to time align.


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Premium Member
Well, are you trying to do surround effects, or to solve the problem of the first two rows not being able to hear clearly?

Key is to realize that:

1) These are NOT the same thing
2) Achieving the former will NOT solve the latter, and will in fact make things worse.

If the problem you want to solve is to get the first few rows hearing clearly, you need to look into implementing front fill speakers; small speakers located at stage height or so, basically at about ear level of those first two rows.

Then, you need appropriate delay processing to align both these front fills speakers and the main cluster to the actors on stage. If this is done properly, it will solve the problem, because those fills will do exactly what their name says, fill in the high end for the front rows that are out of the coverage pattern of the main system.

Yeah, all of the ideas that I had have pretty much been decided against (by me...) after some consideration. I'm rather impulsive. But it would be fun! We set up a couple of game systems in our auditorium tonight on the huge projection screen and played for a few hours, so the speakers that I hung in the back for some environmental effects during a show were pretty fun. We played some hardcore Halo 2, and Revenge of the Sith. Awesome time. But, I don't really know much about how to fix delay issues. Or, really anything for that matter. I just know that they exist. I like to think that I know at least a bit about sound, considering I'm extremely interested in all things audio and have been learning as much as I can, but I'm 16.

Thanks for the advice, though. Very helpful, and it may be a possibility, since surround sound (right now) is out of the question, partly because it's impractical and partly because it's not really possible in terms of the budget.

O, curséd budget, wherefore dost thou torment me so?


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