If U can't go cornfed's, pro, way, check available -- top-quality -- horsepower first. Try active speakers or active bi(multi?)-amping. My guess is you'll need an easy +110db delivering capacity in the full room so, check out the speakers' handling limits!! So, try to get the loudest possible uncompressed, clear sound during the sound checks.
IMO, whatever you do the 1st row will go deaf & the last may need a hearing aid...
As the empty room WILL echo Oz's suggested damping is very important.
In lieu of a tall rack, spread out the equip on smaller supports.
Use of a spectrum analyser would help -- even a rat-shack mike+tone signals, etc. -- for placement.
Make sure the music is "public school" certified!:)
Most of all, good luck!!
IMO, whatever you do the 1st row will go deaf & the last may need a hearing aid...
As the empty room WILL echo Oz's suggested damping is very important.
In lieu of a tall rack, spread out the equip on smaller supports.
Use of a spectrum analyser would help -- even a rat-shack mike+tone signals, etc. -- for placement.
Make sure the music is "public school" certified!:)
Most of all, good luck!!