Puzzle: exceptional sound in custom amphitheater


I'm hoping to build a very good (ideally exceptional) sound installation in a forest amphitheater I'm building on my property. The goal is a large, clear, coherent, moving sound space covering perhaps 20'x20' (or maybe 30'x30'). Potentially with 30+ people milling about.

The main issue is: what mains to people suggest? I'm currently thinking industrial la scala's rebuilt using ALK parts driven by some kind of tube amp. I'd shunt everything below 100hz to subs, avoiding the la scala's anemic bass issues.

However: is there a better speaker family to use? I'd like very loud, very clear, and moving. They would have protective enclosures for between uses, but some resistance to dust would be good.

Related: are there any tricks I can play to make a larger sweet spot using > 2 speakers given that I'll have minimal reflections to fight?

For context:

I used to go to a many outdoor multi-day outdoor music events and while loud, most had poor quality sound. It seems that doing it myself has two nice features. First, unlike making good sound inside, there's fairly minimal reflections / room fighting. (If there any any features outside that cause problems I can use a chainsaw and dozer to eliminate them) Second, there's a whole lot of things pro sound people have to worry about that I can mostly ignore and so can optimize mainly for high quality audio rather than, for example: transport, resistance to spilled drinks, thieves, etc.

As calibration, my home system is dunlavy sc-v's driven by pass xa100.5 monoblocks with two jl 212 subs for lows.
dddrrreee
This was posted by Paul McGowan of PS Audio today. Most systems need walls and were designed that way. Personally, I'd never use a Pass amp outdoors, more like 1000 watt QSC monoblocks.

By Paul McGowan:
Taking walls for granted
The walls in our homes keeps us safe and warm, a modern cave protecting us from the outside elements. Playing music within those walls changes how we hear that music, a trumpet played in a small room vs. a large hall sound very different. The same is true for our stereo systems played within our walls.

You would not enjoy the sound of your stereo system if played outside. Sitting in front of the speaker pair in your backyard, the music would be lifeless, robbed of important information supplied not by the speakers, but by the walls themselves. Thus, in any stereo setup we depend on our walls for good sound.

Think about how much time and money you spend getting your electronics perfected, then compare that to what you invest in walls. If you are like me, the ratio is heavily skewed in favor of equipment. I take my walls for granted, now that I have done what I can with them. And yet, these walls are as important as the system itself. Without walls, our sound is dead.

When we spend any time thinking about walls we mostly consider them a hindrance, like a pesky insect that never goes away. Yet, without walls we will never achieve great sound in rooms, just as without insects our world would cease living; though the little pests are still bothersome.

The next time you sit in your living room with the lights low, think about walls.
you probably want good quality pro gear for hat application.

As was said, home gear is for use in homes not outdoors with no walls.

Having said that, larger OHM Walsh speakers run off a good quality Class D amp will kick some butt outdoors. I can assure that from personal experience using. my OHM Walsh speakers outdoors for parties. It should sound quite lifelike and go loud and clear for minimal cost.
"You would not enjoy the sound of your stereo system if played outside. Sitting in front of the speaker pair in your backyard, the music would be lifeless, robbed of important information supplied not by the speakers, but by the walls themselves. Thus, in any stereo setup we depend on our walls for good sound."

I'm not sure I buy that. Lets say you set your system up outside and play a recording of an acoustic instrument. If you then turned the system off and had someone stand between the speakers and play the same instrument live, you would also have to say the real thing sounds bad as well. Or am I missing something?
My fraternity house used la scalas as our house pa. We would drag them outside for parties etc. they were bulletproof. Sound was far superior to any other pa speakers on campus. They could play so loud even outside it was unbelievable. They are so efficient you don't even need huge pa amps.
Thanks for the responses guys!

Walls are certainly important. (My favorite bromide is that the room is the real speaker, the loudspeakers are just drivers.) However, for many rooms, the walls are the problem, not the solution.

I wish Paul's quote was a bit more technical: does he mean that for residential speakers the frequency response has been modified in anticipation of some frequency ranges been enhanced from reflection?

When I cranked the la scala's outside they seemed to work pretty well. But it does seem that I'll have to go to pro audio.

Have people had any experience comparing D&B to Danley?


And, one issue is that a high quality pro rig seems to run 20-50k, even used. So in the meantime, I'll likely have to get by with a more modest consumer method ---- is there a clear winner over upgraded la scala's for this kind of outdoor use?
DJ and PA speakers are usually designed to be place in the open. Most home speakers actually will tell you how close to walls they should be placed for optimal sound.

As a former klipsch owner (cornwall & heresy) my biggest concern would be plywood speakers outdoors. These were never meant for outdoor use. Klipsch does have a commercial line that is more durable. JBL has some nice rugged speakers as well.