Beste Terry
Op 20 Aug 97 00:39 had jij het over *system balancing*...
TS> As to driver type efficiency and accuracy of reproduction considerations,
TS> some of the best discussions I've seen have come from white papers 
ritten
TS> by JBL engineers, usually in the context of comparing desirable design
TS> traits of compression drivers with various alternatives.
Hmmm...this is not about balancing but high efficiency...NOW you got my 
attention :)
I'm very interested in these 'white papers'...do you happen to have a copy of 
it ? Preferably in an ASCII-text file ? =)
TS> Thiele and Small certainly have considered such things, but usually from
TS> less direct perspectives.
As far as I know, those guys were the inventors of the standard parameters we 
use nowadays to design acoustic solutions.
TS> I sort of wonder if white paper style material was widely published back
TS> when Klipsch was first competing with products like the EV Patrician on
TS> low frequency products.
Don't know...btw this EV you mentioned happens to be Electrovoice ?
TS>> Of course, I was thinking about bone conduction
TS>> of sound to influence brain waves,
TK>> Oh dear....
TS> That's a serious factor when considering why headphones can't produce the
TS> same perceived sound experience as a good speaker system and environment
TS> for some music, despite generally being easier to design for better
TS> response, distortion, stable platform, and freedom from room artifacts.
I do not quite agree with you:
Low frequencies are a sensation to the whole body, and furthermore headphones 
can't give the acoustic sensation of a room or hall due to the lack of 
reflections.....a mostly underestimated fact
TS>  Of course, the NASA lauch pad where they use unusually high bias
TS> voltages on B&K condenser mics so as to not overload at 180 dBspl's could
TS> be another real world example,
Huh ?!? Example of what ?
TS> not to mention my old high school classmate who tests solid rocket
TS> boosters fired sideways at ground level out in the SW US deserts, working
TS> for Morton-Thiokol.
I always wanted to use a J-1 or F-2 liquid fuel rocketmotor as a subwoofer 
>
TS> Pistol shooting alone outdoors can be another interesting acoustic
TS> scenario, as short duration intense sounds can have much more energy (and
TS> cause more damage) than we realize hearing them.
Yep....over 148 dB....deafening isn't it ?
TS> Larger calibers and use of common in the ear protectors have the
TS> same problem musicians using off the shelf ear plugs have:  bone
TS> conduction bypass.  That's where custom molded deep earplugs or over the
TS> head protectors are useful (not to mention acoustically flatter
TS> attenuators being available for custom deep molded earplugs).
Yeah...I know....
TS> Of course, I was suggesting how sound can trigger subconscious alpha,
TS> beta, delta, and other brain wave patterns, pleasurably or with possible
TS> pain stimuli that aren't directly sensed as well as possibly with others
TS> that are.
Try to contact a neurologist....he should know about these things.
TS> Anyone creative with audio, whether with technical or musical
TS> manipulations, should be able to understand what it takes to cause a
TS> variety of human responses, as a basic aspect of understanding how 
elated
TS> human perceptions work.
Oh bugger....I have trouble enough to find out how our perception of music 
can be so specific while we only get some in electricity translated spectral 
info of airpressurewaves in our ear....
TS> Some people want pain, as a masking pattern, as a perceived need (kids
TS> associating high frequency distortion with desired loudness due to too
TS> many crappy stereos, masking more annoying physical pain, to interrupt
TS> and prolong pleasure stimuli, etc.), or for various other reasons.
You lost me here....I'm definitely not into the art of pain-causing..sorry
TS> I've thought about painful but also psychologically disorienting acoustic
TS> stimuli as having possible applications in a burglar alarm system so as
TS> to make a smash and grab crook less likely to stay focused in the time
TS> before police might respond, or for driving rabid church protesters from
TS> areas near abortion clinics, adult book and toy stores, etc.
No problem....try 100W/12kHz feeding it through a long-throw horn. But I 
still don't believe this is a good option.
Better try to scare the church-people away by reading from the Bible...just 
repeat: Do not judge etc. you know what I mean ;)
TS> We see higher frequency simplified versions of pain stimuli acoustic
TS> devices sold to drive away insects.
Some of them even claim to work :)
TS> Pain is a more basal reaction than most other human responses to stimuli.
TS> Learning tricks to trigger it when unexpected can be useful in also
TS> finding ways to powerfully attract attention or stimulate pleasure in
TS> various forms, though usually less predictably across an unknown group of
TS> people.
You definitely should contact your local university about neurology.
TS>> I really wasn't planning to raise the issues of living animal tissue TS>
TS>> damage by sound a couple of serious sadists have tried over the years.
TK>> so ?
TS> Raw energy!  OTOH, something like phaco-emulsification is very focused
TS> sound used to remove cataracts from eyes without cutting.
What are cataracts ?
TS> Are you familiar with the Crown 10 KW 3-phase input power amps, used more
TS> for industrial vibration tables than audio?
Nope...what is the 3-phase deal ?
TS>  Could you picture a human attached to a table driven by 12 of those (4
TS> corners by 3 axis directions)?
Yep...he will definitly be shooked up 
TS> What would the acoustic experience be like if such an arrangement were
TS> used to reproduce audio by vibrating the listener in the surrounding air,
TS> rather than the other way around?
I think he will be sick within a few minutes...you better spend some money on 
vomit-bags then..
TS>> If the above spec's could be met without using more than 150 KW of AC 
S>
TS>> power, I'd qualify the system as having an extremely efficient design
TS>> if based on speaker cabinets.  Consumption of under a megawatt max would
TS>> place it in the realm of average small commercial systems.
Get real, terry...it's like decorating the walls by holding the paper and 
glue the wall onto it 
TS>> Now, dropping some likely assumptions based on the thread, can you TS>
TS>> picture a more efficient way of producing that energy?  How about a
TS>> pipe organ with about 40 HP of blowers, and a rank of pipes out to 64'
TS>> added? That could require under 50 KW of AC power in.
TK>> Never seen one with bigger than 16'....anyway, ik
TK>> would be a nice vibration :)
Correction: Largest pipe in the Sydney Opera House organ is 32'
TS> Very little music calls for anything below 32 Hz.  My ideas for more
TS> subliminal psychoacoustics call for more ability to intermod at 5-14 Hz
TS> rates.  Either way, a pipe organ isn't very space-efficient, but it's 
often
TS> overlooked as to being a marvel of efficient musical transducers.
Anyway...a pipeorgan is a resonance instrument so it is high efficient.
TS> What's the Sydney organ like?
The Opera House grand organ is the largest mechanical action organ in the 
world, it weights 37 tonnes, 15 meter high, 13 meter wide and 8 meters deep. 
It has six departments: Pedal, Ruckpsitiv, Hauptwerk, Brustwerk and Kronwerk.
Designed and build by Ronald Sharp during 10 years. Finished in May 1979.
It contains over 10,000 pipes, grouped into 200 ranks and sub-grouped into 
127 speaking stops, with 28 couplers and numerous percussion and ancillary 
stops.
Piston recoring facilities: Complete pistonsettings recorded or reset in 12 
settings....100 settings may be stored on 1 tape.
Organ key action can be recorded on tape or computer and relay as recorded.
Of course this can only be done by additional electric key action. 
The power supply of the 8000 CMOS IC's (8V) is derived from the 17V/400ADC 
powersupply for electric action. Opto-couplers and Darlingtons are used to 
interface between the CMOS logic and the pallet and stop action magnets.
Wind supply: 9 extremely silent blowers housed in silencing boxes in the main 
case of the instrument, each of which is provided with temperature sensing 
alarms and automatic BCF gas fire extinguishers.
Apart from the 5 manuals and the pedal system there are 2 CCTV monitors a 
telephone/intercom and a talkback mic. to P.A. system
Any more questions ? :)
Groetenzenzovoorts, Thom
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... Met de staart tussen z'n poten.
--- GEcho 1.00
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