Dear Terry
On 01 Jul 97 02:38 you replied on *system balancing*...
TS> Generally I'd just bet cocky people pretending to understand human
TS> perception of audio better than they do that I could drive them out of 
he
TS> room with less than 1/20th of a watt of sound.  >>
Depending on the size of the room and the type of sound, yes :)
TS> Then there was this article in NASA Tech Briefs a few years ago about
TS> using ultrasonics to create a vibratory crack in the end of a pipe bomb
TS> to allow cap removal without serious risk of detonation....
never heard of really....seems to me a smooth way to do the job...
TS> I just thought the above system would offer some interesting design
TS> challenges, and could trigger an interesting adjunct discussion about
TS> little discussed transfer efficiency of drivers and coupling systems.
Well ? :)
TS>   Of course, I was thinking about bone conduction of sound to influence
TS> brain waves,
Oh dear....
TS> and impose pleasure patterns in such intensity as to be disorienting, or
TS> pain for more reasons than the listener would understand.
Why, on earth, would you like to cause pain anyway ?....
TS> I really wasn't planning to raise the issues of living animal tissue
TS> damage by sound a couple of serious sadists have tried over the years.
so ?
TS> If the above spec's could be met without using more than 150 KW of AC
TS> power, I'd qualify the system as having an extremely efficient design if
TS> based on speaker cabinets.  Consumption of under a megawatt max would 
place
TS> it in the realm of average small commercial systems.
There are cabinets with a 7% efficiency
TS> How many people here realize that at average home system (in)efficiencies
TS> the above would require over 5 megawatts of line power in?
What IS the average ?.....84 dB/1W/1m ?......92db/1W/1m ?
TS> Now, dropping some likely assumptions based on the thread, can you
TS> picture a more efficient way of producing that energy?  How about a pipe
TS> organ with about 40 HP of blowers, and a rank of pipes out to 64' added?
TS> That could require under 50 KW of AC power in.
Never seen one with bigger than 16'....anyway, ik would be a nice vibration 

TS> For comparison, the average moderately large church pipe organ has 16'
TS> pipes and a 3 HP blower, while the largest Austin organ I've ever been
TS> inside uses a 15 HP blower, a ton of different special pipes on two air
TS> chests about 6.5' x 15' x 30', but wouldn't produce sound below 16 Hz or 
at
TS> the required volume (1922 World's Fair organ in Philly is one of the
TS> largest in the world).
Sydney Operahouse Organ... dated somewhere in the '60 I guess...
TS> Terry
Hi :)
Groetenzenzovoorts, Thom
*----*
... Vertellen in geuren en kleuren.
--- GEcho 1.00
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