Re: JBL SRX / QSC PL236 underpowered?
Forgive my basic turn of phrase. What I meant was, if I have a speaker rated at 1000W and I'm powering it with a 10W amplifier, then the amp to me is under powered for the job. I do take your point that what I would effectively be doing here is under powering my speaker.
I'm not familiar with the phrase, "75 degree box"?
I agree, the system should be designed for the application always. But that's not what I am trying to do here. The band only have two tops and two subs. They play two types of venues:
1. The type of venue their PA can handle.
2. The type of venue their PA cannot handle.
If they're playing venue type 1, they use their PA the way they've always used it. In other words, the application here isn't a venue. It's people. If they're playing venue type 2, they will hire a bigger PA.
What I'm trying to decide is what I need to drive those boxes with if I was using them as JBL designed them to be used. From there I can decide if I have the right amps for the job. Then when I have the right amps, I can define what is a venue type 1 and what is a venue type 2. I know it's arse about face, but the fact is, bands don't design systems around venues. They just turn up with their PA and do the gig or they hire a bigger PA and do the gig.
Which brings me to my final goal - if this system is running with say 10W amps when it should really be running with 3000W amps then the system is capable of much more than it's currently delivering. In other words, we reconfigure it, get bigger amps and suddenly we have many more venue type 1s and fewer venue type 2s. The band won't have to hire gear for bigger venues so they will save money. As they don't have any money, this is a rather cool plus point.
Does that make sense? 
Of course, with the gear the band have got, this is probably the right answer:
How about if the band walked into a 'JBL SRX shop' and said, "I like this JBL SRX thing here. I've got a rock band. If I buy two of these tops, what else do I need to make it work the best for me and my mates?"
As musicians, they're not going to be able to process, "Well, you need to design the system for the application and that depends on the sound pressure level you're trying to achieve etc etc." They just want to buy a PA that will do for most of the normal sized gigs they get (type 1) and know that they are getting value for money because they have quality gear which = quality sound and their PA is useful right up to its design limit, which a 10W amp powering a 3000W speaker wouldn't be.
