One of the bands I play with, the trio, has two 15" JBL self-powered PA speakers and three 12" JBL powered speakers. We typically use the 15" set as our mains and the three 12" JBL's as our on-stage monitors. I believe there is no separate amp because the speakers are all powered and we just run speaker cables out to their inputs. Both the 12" cabs and the 15" powered cabs have 1500-watt class D amps built in. So, 4 of those would be a max of 7,500 watts...guess you'd call that medium although I really think of our PA as "small".
The other band has a mix of powered and un-powered speakers. The mains we usually use are a couple of very nice 2x12" powered PA cabs and then we run five monitors which are a mix of 12" with horn and 15" with horn speakers. We have 5 of those. I think two of those are un-powered. Not sure what wattage rating amplifier is powering those. Sometimes they'll put our 15's up as the mains. In any case I think we are running about 8,000 to 10,000 watts by the time everything is hooked up and running.
We also have two sound boards. The smaller board (16-channel) is used for most spots and then we'll pull out the huge 32-track Allen & Heath one if the drummer really needs to hook up all 8 of his mics (he still can't believe he's supposed to provide his own cords for those mics).
So, although I would call the trio's PA medium size, the 5-pc. group's PA is definitely large. Normally we only mic the voices and the kick drum but for big places we'll mic the guitar amps, the keys amp, and use all 8 mics on the drums. We almost never mic my bass because it just doesn't need it. The only time I've had my cab mic'd was when we were playing a festival and they were also recording our set.
Powered speakers are definitely the way to go but I did fall into a lot of my stuff at a great price so I just went with it. I have a Carvin analog 16 Ch board as backup and the Behringer 18ch wireless that we'll probably use most of the time because it's just so easy and portable.
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