For sound amplification, i use the following power amplifiers in my racks:
1 2000 watt stereo power amplifier, model ap-1200 made by yorkville sound,
1 4000 watt stereo power amplifier, model ap-3400 made by yorkville sound,
1 crest audio model 10004 power amplifier, 4 channels at 2500 watts each @1
  ohm per channel (major current draw),
for BASIC mixing i use a sa-909 cheapo mixer (does the job great)
for advanced mixing i use a yamaha 12 channel mixer (kinda in rough shape 
from road shows)
for speakers, i use speakers that DO last for more than 3 hours (unlike JBL):
2 ex-1000 Elite speaker cabinets, made by yorkville sound (2 15's and a 9 x 6 
horn and 2 2 inch peizo tweeters, (50 hz and up) powered by the 4000
2 Yamaha 4115H-II's for mid bass region (70hz and up) powered by the 2000
4 sw-800's 800 watt 8 ohm subwoofers, 1 18 inch woofer in each cabinet using 
reflex compound loaded horn design for up to 148 DB of SPL from each cabinet,
The cabinets above are rated as follows:
the ex-1000's are 4 ohms 1000 watts each, driven at 1700 watts average RMS, 
not PEAK,
the yamaha 4115's are driven at 375 watts RMS each, not PEAK, it says 240 
watts program on the back of each cabinet,
the sw800's are kind of linear driven, the 10004 amp is a wierd class H 
amplification model, it is not too linear because of its class, it drives 
each subwoofer at about 1500 watts peak.
The 2000 watt and 4000 watt are both class AB, and the highs and lows are 
crisp and tight, never overexagerrated.
I am planning on getting more control over my equipment in the future (noise 
gates, compressors) as i plan to expand my equipment a bit more.  I just wish 
i can afford clusters of MEYER sound cabinets (generates 120 db at 100 feet), 
but MEYER is outta touch with real life prices, each cluster (4 18's, 6 15's 
and a few other wierd ribbon/horn/peizo tweeters and 10 and 8 inch midranges) 
costs close to over $23,000 per cluster.  I AM open to suggestions from 
anybody else that can direct me in the direction of durable speakers (a few 
thousand watts of bass drum kick without unwrapping its voice coil like 
JBL's).  When i first started, i had the 2000 watt amp and the Yamaha's, then 
a few months after that i ran into a bad dilemma, someone who rented the 
speakers off me and the 2000 watt matching amp hooked the yamaha's up to a 
QSC USA 850, and well, the stupid dirty QSC took out the tweeters on both 
Yamaha's.  Well, i charged the guy extra money to replace tweeters, no 
problems there.  Then i went and bought the 4000 watt amp, and matched the 4 
sw 800's to the 4000 watt amp, no problems at all but i found that i was 
running low on current on the way the 4000 watt amp was built, so i souped up 
the internal power supply (it had a measly 1500 VA toroidal xformer, so i got 
2 1500 VA toroidals, 1 for each channel, and souped up the capacitance on 
both channels, then i was getting the right amount of damping on the woofer 
cones (before i beefed up the supply, a kick drum sounded like a muddy thud), 
now from those 4 18's, it feels like a large kick drum.  Then i changed half 
my setup and bought 2 ex-1000's, and ran them off the 4000 watt amp, no 
problems. Then i bought a crest 10004 amplifier, and decided to run the 18's 
off the crest, so i did, no problems, until i saw the line cord that plugs 
into the wall - that was a problem, a 50 ampere capacity cord was on there.  
My 2000 and 4000 watt amps have 1 and 2 split line cords for each channel 
respectively, but this one took the cake.  In the future i am planning on 
running 1 bridged power amp for each speaker for less crosstalk between 
amplifier chassies.  I noticed crosstalk definately on the 2000 watt amp 
because it has 1 1.5kva xformer, like the 4000 watt amp, so when i run my 
left speaker with more bass, the right speaker gets softer in the bass 
region.  I know that bridging an amp will increase the slew rate, wattage, 
and decrease the damping factor, but that is the only way of protecting 
speakers from semi-reactive loads taken on by paralleled speakers.  So far i 
do not run any of my speakers in parallel, and do not plan to because it 
causes more heat in the voice coils (blew many Cerwin Vega commercial 
speakers this way).  As for protection equipment, i just use alot of MOV's, 
and line breakers on my racks, and well, i am borrowing an auto switching 
device (beta testing for a friend), it is supposed to detect correct line 
voltage and switch over to the corresponding plug in the back, and it does, 
but it takes 3 seconds to detect voltage, phase etc.  It will give you 2 red 
warning lights if the voltage exceeds 250 volts, and a yellow light if it is 
a normal 120 volt plug, and a single red light to tell you that it is a 250 
volt receptacle.  It has LARGE 30 ampere loud relays, so even the clicking 
will tell you what voltage you plugged it into (3 clicks for > 250 volts, 2 
clicks for 250 volts, and 1 click for 120 volts, and a loud BUZZ if it is 
from 40 volts to 90 volts).  I really doubt that this beta protection 
mechanism works under DC voltages, but i doubt that anybody will have an DC 
receptacles (welding gear?).
Laszlo
--- BBS 42
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