I may be about to create some ghosts.
No, I don't mean I'm going to kill someone- what I have in mind is a good deal more devious than this.

Ever heard of infrasound? Probably not, so let me throw in a few links for you: Wikipedia, one interesting article, another interesting article. Go skim through them, at least- they're well worth your attention. Go ahead, I'll wait right here for you.

Done? Okay, good. Now to my plans...

I figure that if I take a large sheet of rubber- say, a chunk cut from a truck inner tube- and stretch it, drum fashion, over the end of a cylinder that I'll have a good beginning for a tremendous sub-woofer. If I mount a nice thick iron washer in the middle of it and make a really powerful electromagnet out of a railroad spike and a lot of windings of insulated wire and mount that behind the washer, it will put out a very high amplitude and low frequency sound. (That is, an extremely loud bass tone.) I can then make a very basic oscillator and tune it to around 17 to 19 Hz and use it to run an amplifier chip, run that through a MOSFET so I can put some real power behind it, and have an infrasound generator that will rattle your bones.

And why do I wish to do this, you ask?

See, my next door neighbor is an utter twat. He has a large Dalmation who he has trained to be rather aggressive. For whatever reason, he is out in his yard at all hours of the day and night- I've heard that damn dog baying at midnight, and five in the morning, and at all hours in between.

Not that long ago my daughter was walking along the other side of my fence on her way to my house when the dog charged her and bit her, drawing blood from her upper thigh. Did the neighbor hurry over and make sure she was okay? Did he apologize to her or to me? Hell no. He told her she needed to watch out for the dog because he was getting aggressive these days, and when I called Animal Control he had the nerve to say that she had been asking for it by wearing her headphones and not paying attention to the dog. (I wonder what his take would be on it if one of his daughters got raped. Grrrrrr...) Since then he and I have not spoken. However, the dog continues to bay at everything at all hours of the day and night.

My plan is to make four of these generators- I already have the cylinders of PVC pipe- and line them along the fence facing toward his house. I will run them all off the same circuit. I will then hook the thing up to a motion detector and set it up on the tree near the fence, pointed toward that yard.

Then when he comes out in the middle of the night with that dog, he'll get Teh Fear and have no idea why. God knows what it will do to the dog, but it should be entertaining to find out.

I'll let you know how well it works...
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 12:52, 19 replies)

Wouldn't it be easier .....
Just to give the dog some food with laxatives in and wait for it to shit all over the neighbours house.

Just a thought!
( girlinthehole, Thu 3 Jul 2008, 12:57, closed)

And I name thee
MacGuyver
( Kroney, Thu 3 Jul 2008, 12:57, closed)

I've thought about
giving the dog all kinds of things, including antifreeze- but that could have legal repercussions on me.

As far as I know, there is no legal statute against using subsonic vibrations to make someone freak out.
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 13:00, closed)

Voigt 1/4-wave resonators
I've designed and built several of these, the lowest of which resonated at 25Hz, driven by a 10" woofer. Rattled my patio door windows pretty badly 30 feet away.

I've also had the pleasure of "listening" to a bundle of 6 Bose Acoustic Wave Cannons simulate thunder. Jesus wept.
(JohabMorelli is spenging merrily away, Thu 3 Jul 2008, 13:10, closed)

Oooooooo, shiny!
https://mywebspace.wisc.edu/jstalnak/web/VoightPipeSpeakers/ This looks like fun! I have plenty of wood and tools for working it... hmmmmm...
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 13:14, closed)

Woo
Thats quite the scheme. Were you ever in the A-Team?
(Oben, Thu 3 Jul 2008, 13:29, closed)

Nah.
I just like messing with peoples' heads...
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 13:35, closed)

Get A Gun
that is all.

Shoot the owner. Shoot the dog - if it's that aggersive it's beyond help.

Blame the little green men for telling you to do it.
(TheWeeWitch hasn't been here much recently .., Thu 3 Jul 2008, 13:53, closed)

my mate was telling me
that there's a resonant frequency that makes people lose control over their bowels.

The plan would be to build a device emitting this frequency, mount it on top of a van, and then park it in the centre of London. Probably outside Buckingam Palace during the changing of the guard.
( rofl harris, Thu 3 Jul 2008, 14:16, closed)

That would be the Brown Noise.
There was actually a lot of research done in this field in the 1960s. Seems to me it was in the low 20 Hz range that it was thought they could do this.

The theory is that you can generate a sound that is approximately the resonant frequency of the abdominal cavity, causing vibrations to irritate your colon so you got instant diarrhea. An interesting concept, to be sure. Only one little hitch:

No two abdomens are quite the same dimensions. My belly is a different size from yours, which is a different size from that of Tourette's, which is a different size from rachelswipe's, which is a different size from Pooflake's, which is a different size from Prince Harry's, and so on.

Too bad, really- it would be a lot of fun to hack into the speakers at a Spice Girls Reunion concert and make the crowd think that it was the music that gave them the squitters.
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 14:25, closed)

hmm
interesting.

Maybe there'd be a range of frequencies that could be used that'd get *most* people.
( rofl harris, Thu 3 Jul 2008, 14:33, closed)

You know...
...I think he's really gonna do this folks!!

TRL: make sure you have a camera with a night-sight on it for the big day - I see YouTube fame awaiting you.

Just keep out of shot - a film of TRL jumping from foot to foot rubbing his hands with glee would totally spoil the effect.
(Che Grimsdale Best before:, Thu 3 Jul 2008, 14:57, closed)

Oh, no question that I'll do it.
It's just a matter of when. I need to take the time to do the fabrication and testing, and to build the oscillator and get it tuned with a small potentiometer- which means that I need access to an oscilloscope for a little bit, and I don't happen to own one. But I know people who know people, so it's feasible. Add to that that I have an electrical engineer quite intrigued by this concept and that he's already suggested using a 555 timer for this, and I'm already halfway there...

Trust me, it's gonna happen!
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 15:07, closed)

brown noise
... I think it's unlikely that anybody's abdominal cavity is much good as a resonator; but if drive a crap resonator hard enough you can still get some resonant enhancement -- just not very much.

Perhaps loud enough brown noise might work (if indeed it does) directly, without the resonance effect.

Any passing acoustic anatomicians care to comment on losses and frequency response in the human abdominal cavity? No?
(haberman is singing in the changes, Thu 3 Jul 2008, 15:54, closed)

Don't use a 555...
I'm no expert but something tells me the square/pulse output wave from the 555 won't be quite as good as a proper sine wave.

May I suggest something like this?
www.freecircuits.net/images/pages/opamp.28.gif

By the way, Brown Noise has already been proven to be absolute bollocks (Mythbusters and their stupidly powerful and elabourate rig being a good example) on many occasions. It Doesn't Work.
(keyboardman, Thu 3 Jul 2008, 15:58, closed)

Brown noise
Our good friends on Mythbusters have pretty comprehensively blown this idea out of the water. Shame, as it would have been great if it were true!
( Olembe Refuses to write in this space, Thu 3 Jul 2008, 17:16, closed)

However, even if Brown Noise is a myth,
I do know a karate instructor who is aware of a pressure point, which, if poked hard enough, will cause someone* to void their bowels. Unfortunately he refuses to tell me where it is.

_{The person being poked, obviously, not just a random person in the surrounding area}
(LongJohnBaldry, Thu 3 Jul 2008, 21:15, closed)

phwoarrrrrrrrrrr
you genius
you have to youtube this.
(Freddles, Fri 4 Jul 2008, 10:54, closed)

@Crow
YOu can do it with the bladder too, had it done to me by a guy at training, just hard enough to go 'ooh' but not enough to release, thankfully!
(Fuckarma was masturbating into your handbag, Tue 8 Jul 2008, 11:42, closed)