* In a message originally to Drew Hohmann, Terry Smith said:
TS > -> continuous output power.  Burst energy was measured MUCH higher, at 
>
TS > 12,000 watts total output power.  In bridged mode, this amp
TS > is pure -> lethal because it supplies 100 amperes with a 50
TS > percent reduction in -> damping factor at 167 volts.  I can
TS > ARC weld with this amp in bridged -> mode without clipping
TS > and a bit of heat off the heatsinks in the amp.
TS > DH> WOW!!!  Now that is one he|| of an amp!!!  4,000 watts is an awful
TS > lot.
TS > DH> What the heck do you have this hooked up to? 4 18"s?
TS > Those are all sort of "Oh, wow" numbers, just as Sears and
TS > Caldor sell 4 HP vacuum cleaners (none of which consume
TS > enough power to run a 1 HP motor).  No load speed/voltage
TS > times just short of self destruct torque/current, and you
TS > have an instantaneous peak extreme.
TS > As solid state audio amps, Crown's 10,000 watt models are
TS > the largest of which I know in commercial production.
TS > Those use 3 phase power, and have a rated output Z of 0.67
TS > ohm.  In an extreme case, you might use 12 of them (120 KW
TS > total) as quad symmetrical pairs on the X, Y, & Z axis of
TS > an industrial shaker table designed to reveal vibration
TS > problems in a car or piece of mil hardware.  In theory you
TS > could use them to drive 8 @ 8 ohm 1200 W woofers, but it's
TS > better to use 4 smaller amps with more flexible power needs
TS > and better damping factor.
Well, how well does the crown 10kw amp old up it's damping factor at 2 ohms?. 
Alot of people i know run their amps at either 2 ohms or 2.67 ohms 
continuously without any problems, especially indoors.  These days i RARELY 
see amps double their output power as the impedance is halved.  My largest 
amplifier puts out a measured 2,000 watts per channel into 2 ohms per channel 
on a run time limited basis of only 6 hours before the amp's thermal lights 
come on.  But it does not double from it's 800w into 8 ohms to 1325 watts 
into 4 ohms then to 2,000 watts into 2 ohms per channel.  Bridged mode is 
just plain lethal.  And this amp does not even use 3 phase power at all, only 
2 20 ampere 117 volt twist lock plugs.
TS > The larger Stewart amp is about the biggest for which I see
TS > a practical need in pro audio.  At 17 lbs. and 2 rack
TS > units, one can power two double 18 bins and 4 double 15
TS > plus mid & high wedges with a single rack two men moving
TS > the bins would find easy to lift.  (5 amps, 2 on 18's, 2 on
TS > 15's, one in stereo mode for mids and highs, under 150 lb.
TS > rack with crossover and AC distribution)  That allows a
TS > choice of using a temporary 60 or better amp 240 single
TS > phase drop, or scarfing up 4 120 circuits per rack, for an
TS > 18,000 watt four way system.
17 pound amplifier running bassbins?,  Does it have an external transformer 
or does it run directly off the 120AC without a toroid?
TS > Of course such amps have some peak headroom too, but that's
TS > not what sustains solid audio outside someone's bedroom.
TS > Besides, with a 10,000 W amp, 2 AWG welding cable would be
TS > inadequate for speaker wire.
Depends on current gain.  I use cabling of no more than 20 feet from the 
speaker of 8 AWG cable for the 100 sustained amperes per channel my largest 
amp can do without going into protect if a short circuit would happen (i've 
tried it, it melted the cable and dimmed the lights in the whole 240/120 volt 
distribution box).
TS > Now for a really big audio amp, look at the modulator
TS > section of a high level modulated shortwave transmitter
TS > sometime.  Those can exceed 500,000 KW audio output for a 1
TS > MW TX.  (Let's just hook these 300 8 ohm speakers in
TS > series....)
RF has no room in pro audio, unless you were talking about RF amps.
Laszlo Sokolai
Team ANTI-Windows95/PRO-OS2/PRO-Unix
lsokolai@bbs42.com
--- BBS 42
---------------