Crap music

[scott]

http://www.meyersound.com.au/brownnote.shtm

[Chris H]

The instant cure for constipation ??????

[Chinagraf]

I saw that episode,but Adam was like 4 feet from the subs. Wouldn't you need to be further back to get the proper effect of such low frequencies, due to size of the wavelength?

[wez]

I saw that episode,but Adam was like 4 feet from the subs. Wouldn't you need to be further back to get the proper effect of such low frequencies, due to size of the wavelength?

no.

but... as much as i love mythbusters, you could drive a truck through some of the holes in their methodologies. this one was no exception.

[Chris H]

Bottom end can be fatal ! Did some reading last year on the development of a weapon that uses a very low frequ to fatal effect. I'll look up a link

[Simon B]

I thought it was more a signal generator that could produce very low signals that could knock over sky scrapers.

[scott]

On the program they did show a supposed test of a sonic weapon. Looked kinda like a satalite dish, but I don't think it was a low freq thing.

Come to think of it, might have been a piss take.

I've been mucking about with some software synths lately and the results could be considerd an aural assault.

[mfdu]

yeah - those wacky americans have been playing with a pain ray which uses highly focussed sound waves to achieve an almost microwave density, inflicting great pain upon the poor towelheads.

(i am not entering into any seppo/towelhead bashing. in fact, according to my wife, i am now sporting a taliban beard.)

trying to find the link on www.wired.com but failing . . .

sigh.

chris.

[Chris H]

On the program they did show a supposed test of a sonic weapon. Looked kinda like a satalite dish, but I don't think it was a low freq thing.

Come to think of it, might have been a piss take.

I've been mucking about with some software synths lately and the results could be considerd an aural assault.

Visited an Australian Navy Ship a few years back and on the deck aft of the control tower was a yellow line with the warning"Don't stand beyond this line during operations. Answering my enquirey the tour guide informed us that the level of the microwave signal used to guide the machine gun on the stern was so strong that after about a minute you would feel sweat on your face but your insides would be cooked.

[chris p]

... and right there is the difference between electromagnetic radiation and pressure waves.

[scott]

But I learned, on myth busters actually, that microwaves dont cook from the inside out? Confused now.

[mfdu]

[quote="chris p"]... and right there is the difference between electromagnetic radiation and pressure waves.[/quote]

i'm guessing this is in response to my comment about soundwaves at almost microwave density.

stupid comment. what was i trying to say? aaaah who cares. if i can't flesh out the actual facts, then who else could be bothered?


:)
chris.

[Peter Knight]

Hahaha I remember my social studies teacher in high school telling us about how they first discovered the cooking effects of certain radiation bands. He reckoned that Russian soldiers at an airfield in Siberia or something found that their night shift was a lot warmer when they stood in front of the radar array!

Dunno if that's true or not.

But it reminds me of a bloke I know who used to be a sales rep for some agricultural company - he was telling me that when DDT first came out, the company selling them the muck sent a rep out to show his company all the wondrous benefits of DDT. One of my friends coworkers asked the guy "Is this stuff safe?"

The guy says "Sure". Obviously he had prepared for this question to come up. So to show the assembled sales reps just how safe the stuff was....

He drank a cup of it.

[chris p]

... and it would have done him no harm. DDT is deadly to insects, not humans! The problem is that it stays in the environment for a LONG time - and so stays in the food chain for a long time.

DDT has been banned now for what, 20 years, but it still shows up in human breast milk thanks to its environmental longevity. It wasn't banned because it was poisonous to humans, it was banned because it wouldn't go away.

(Sigh) I'm scared I know this sort of $%!+

[jkhuri44]

one of the support staff at my uni (UTS), built a larger than life whistle...capable of pumping out sine waves down to 5Hz.

thats some crazy s**t...

and elsewhere, i read that 18Hz is the sympathetic frequency of human eyes and exposure to it at high enough SPL could cause blindness...

not sure if its true...but interesting if it is!

[Kris]

one of the support staff at my uni (UTS), built a larger than life whistle...capable of pumping out sine waves down to 5Hz.

thats some crazy s**t...

yeeeep..... there's our tax dollars hard at work.

[jkhuri44]

yeeeep..... there's our tax dollars hard at work.

if he was paid to do it at UTS, that would be the case, thank god this was something he did privately, haa :lol:

[chris p]

http://www.digitalgrabber.com/audio/the_60_inch_subwoofer.html


and understand this, it was designed as a CAR audio.

I love the concept that during play, "the entire vehicle ballooned in and out several inches". I just didn't think that cars were that flexible.[/url]

[jkhuri44]

oh man...

thats....wow....

that kinda stuff is really pushing it to the limit....apparently the loudest sound possible is 190 dB SPL (the limit of air pressure, im probably wrong, but something like that)....and this thing's pushing further than 180??!?!?!

wow...talk about hitting the reds...hehehehehehehe

[Mark Bassett]

Atmospheric pressure is about 100 kPa. So, in air at normal pressure, one cannot have a symmetric wave whose pressure amplitude exceeds 100 kPa, because one cannot have a negative pressure in a gas. (One can, however, have negative absolute pressures in liquids.) A peak of 100 kPa corresponds to a pressure amplitude of 70 kPa rms, which in turn corresponds to a sound level of 191 dB. An asymmetric signal such as a single compressive pulse could, in principle, have a larger amplitude than this. Pulses with amplitudes comparable with 100 kPa quickly distort as they travel. Very close to an explosion, for instance, the sound pressure in the shock wave could exceed 100 kPa. If you know the peak pressure Pp in kPa, you can estimate the sound level as 20 log(35,000,000*Pp/kPa) dB.

From http://www.phys.unsw.edu.au/~jw/musFAQ.html

[Roy]

Air pressure at sea level is 101.7kPa (1 bar). Higher temps can increase it as well. So at a place like New Orleans where it's actually below sea level- you could theoretically have a louder gig than here in the Blue Mountains. Hahaha.

[JulienG]

The best example of > 191dB is the PEPCON disaster of 1988, I strongly recomend watching the video, it's amazing.