help to build a sonic disrupter, will report results

disrupter

Hi, I have a small rooming house in Vancouver BC that is across the street from a homeless support center run by the city, problem is we are unidated with homeless people at the entrance to our building and this is causing many problems. Police have suggested I set up a constant water spray to detur them, problem here is the building is old and wooden and this will hasten the rot.

I would like to try an infrasonic radiator (or speaker ?) system, i.e. sub 20 hz sounds played in short bursts to see if this make people uncomfortable enough to move away.

Any suggestions on what is needed. I will build and someone or this forum can learn the results for free future use. I report the whole process as it goes, would like to keep it under $1500.00 Thanks.

Face

http://www.edesignaudio.com/edv2/product_info.php?cPath=21&products_id=104

Hook it up to a PC playing a 20hZ on loop.

You could also look into a infinite baffle setup.

Serendipity

A good infinite baffle subwoofer or a large sub would do the trick.

I'd recommend the 15" Dayton Titanic MKIII - they are excellent woofers for the fraction of the price:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-420

Just build an enclosure for the sub, power it with an 800-1000W amp, and you'll be golden.

disrupter

thanks APPADV, I checked out the 15" Dayton Titanic MKIII, great price and I can certainly build the baffeled enclosure BUT its range is 19HZ to 500HZ, I would like to experiment with frequencies down to about 10HZ, (I have a friend who says he can make a cd with various frequencies for various times to try out) so I think I need another reference to a sub sub woofer. . . also I have just heard about "Tubes" do you think they would handle these low frequencies?

AND, thanks FACE, I have now looked into the infinite baffle setup [see below] but do not understand how this would get the speaker to radiate to lower HZ levels, as this seems to be the big problem at this point. Do you know if I could make a long infinite baffle horn using a transducer type speaker?


[Infinite baffle - An “infinite baffle” enclosure is not really an enclosure, rather it is more like a wall of infinite height and breadth. The sound waves from the rear of the woofer cannot get around the front, thus solving the problem of rear-to-front-phase-cancellation. A closed or sealed box, with a woofer mounted in one face, effectively stops the sound radiated behind the cone from reaching the front, so it is called an infinite baffle enclosure. The drawback though is that because a driver moves as much air behind as it does in front, the box must be quite large (10 cubic feet or more) to prevent the mass of trapped air inside the box from acting like a spring, which can raise the effective resonance of the speaker.]

Serendipity

The 19-500Hz frequency range on the Dayton woofer is measured anechoically, which means without any gain from the enclosure or room. With a 3.0-5.0 cubic ft. DIY enclosure, expect a frequency range down to approximately 16Hz. In addition, two of these woofers in the same enclosure would extend the frequency range even further. That might just do the trick.

janmike

The classical music thing is used quite often to deter punks from hanging around. They have done it outside malls with impressive results.

wingnut4772

janmike wrote: »

The classical music thing is used quite often to deter punks from hanging around. They have done it outside malls with impressive results.

Or you could get Cartman and a bus...." California..."...

dudeinaroom

Just set up a Tesla coil, that should keep them away.

Serendipity

A tactile transducer or "bass shaker" might also work, there are many available from places like Parts Express and Tactile Sound.

jimmyzen

appadv wrote: »

A tactile transducer or "bass shaker" might also work, there are many available from places like Parts Express and Tactile Sound.

Ahh! The hunt for the infamous "Brown Note"!!!!

dorokusai

Every time I see this thread I think I'm 20 years in the future.

disrupter

thanks forum members for the suggestions, yes I'm looking for the brown note and the pink note etc. So far I am following APPADV's suggestion to look at transducers and have settled on the TST429-Platinum (tactile sound) with a single channel 300+ W amp. the TST 429 runs down to 5 Hz. Iwill show a detail of the moving entrance ceiling panel when I get this built. ANY suggestions on what frequencies will cause the Brown or pink notes etc would e greatly appreciated, or any suggestions for experiments you'd like to run on this device re frequency & duration are most welcome. Thanks again....so far.

wingnut4772

So this is totally out then?

California

jakelm

This thread...cannot be serious....lol....:p

Building a subwoofer to scare away , the homeless?

Serendipity

disrupter wrote: »

thanks forum members for the suggestions, yes I'm looking for the brown note and the pink note etc. So far I am following APPADV's suggestion to look at transducers and have settled on the TST429-Platinum (tactile sound) with a single channel 300+ W amp. the TST 429 runs down to 5 Hz. Iwill show a detail of the moving entrance ceiling panel when I get this built. ANY suggestions on what frequencies will cause the Brown or pink notes etc would e greatly appreciated, or any suggestions for experiments you'd like to run on this device re frequency & duration are most welcome. Thanks again....so far.

The TST429-Platinum is a good choice and would do the trick. The next step would be to get it installed/mounted in the ceiling panel and hook it up to the amp of your choice. I'd recommend a Crown or QSC Audio unit for this application.

honda cber

my personal opinion is that this is not going to do much more than irritate the people INSIDE the building.

remember that the room being pressurized is....... outside... no "room", just open space. ever played a subwoofer outside in open space? i think you are going to be disappointed, and with a lighter wallet to boot. especially since you will not only be relying on passive materials for transmission (a ceiling tile?) but will only be powering that with 300 watts. you may be lucky to be able to hear much more than rattling and feel a slight vibration on the outside.
OTOH, frequencies that low will readily transmit through the wooden structure, possibly rattling windows, pictures, etc. for a lot of my teen and adult life, i have performed and/or ran live sound--- in applications ranging from acoustic music in a small bar or coffee house, to shows or dance parties for hundreds+. sometimes outdoors. it takes a LOT of power and driver surface area to effectively project low frequencies out-of-doors.

again, my somewhat factually-supported opinion. at least, that is what i get from reading about your application. correct me if need be.
a

disrupter

thanks HONDA CBER,

the ceiling tile is a 4' x 8' x 6' piece of 3/4" plywood which I indend to float from the rest of the building with rubber bumpers or some other vibration insulator. the TST429 trasducer is supposed to move and use a 4' x 8' X 3/4" piece of plywood. the ceiling tile would be about 6 or 7 feet above the people sitting & blocking the entrance way.

I really appreciate and respect your knowledge vis a vie the power required to project sound (and in this case infrasound) into the outdoors. The entrance way is closed on 3 side, though 2 of these angle outwards. I wonder what to do now, this seemed like an interesting experiment - instead of spraying them with water (which the Police have told me to do) I was going to spray them with infrasonics which I thought was so much more subtle. Any suggestions, anybody ???

disrupter

RE the comment that perhaps 300 watts is not enough power for he TST429 transducer to make noticeable sound sensation in the outdoors.

I just checked my research links and one at:
http://www.animalvoice.com/

explains that infrasound does travel long distances in the outdoors, in fact this is one of the reasons animals use infrasound

-- another really interesting reason is for healing bones and tendons, check out the "Cats Purr" in their Bioacostics Research tab.

They say:

"INFRASOUND
Infrasounds are sounds below the human range of hearing, technically 20Hz, but most adults will be hard pressed to hear anything below 40 Hz. Your average sub-woofer speaker goes down only to 25-40 Hz. However, at high enough amplitude (very loud) you can feel infrasound, it will shake you. Anyone that has ever watched the space shuttle take off will tell you that it shook the ground and rattled windows, that is infrasound! Infrasound is a long, sound wave. It can pass through forests, buildings and even mountains. For example, the space shuttle taking off creates a very loud sound pressure wave of .02Hz (very, very low). It takes @20 minutes for this sound to reach Langley Air Force Base in Virginia, from Kennedy in Florida. This sound wave will pass through everything on its way, and will continue around the earth until it finally dissipates due to attenuation (lessening of the amplitude of the signal over distance/time).

Animals that generate infrasound include elephants, whales, alligators, hippos, rhinos, giraffe, lions, okapi, tigers, and several birds. The common thought used to be that only large animals could generate infrasounds, we now know that smaller animals do produce infrasound and there are probably many more we do not know of.The animals that can detect infrasound either seismically (through the ground), atmospherically (through the air) or underwater, are too numerous to mention. Fauna Communications specializes in studying this type of sound."

[emphasis not in original]

My point is that since "smaller animals" make infrasound ( and the unmentioned reason is that they do this for communication, as do the elephants and tigers, etc.) wouldn't 300 watts be enough using the TST429 infrasonic transducer on a piece of 3/4" plywood (as specified by the maker of the trasducer) actually cause the sound to be felt 6 or 7 feet away, in a partial outdoor space. I am thinking more likely than not likely.

honda cber

interesting... i am having trouble wrapping my brain around the physics of this, though (your proposal, that is), and can only theorize to its effectiveness by using what i do know. i like the reference to .02 Hz. i havent a calculator handy, but isnt that one cycle per *50* seconds!? try and reproduce that without something incendiary. however, 4x8' is a lot of surface area, and having walls should help to direct the sound if they do not absorb it at those frequencies. might take a bit of fine tuning to find a usable frequency. but i am intrigued (and smiling--- damn vagrants!)

i will be curious to read of your results; please post back once you have it up and running.

i still think it would be more comical to have water spray. "what the....?"

a

Serendipity

disrupter wrote: »

RE the comment that perhaps 300 watts is not enough power for he TST429 transducer to make noticeable sound sensation in the outdoors.

I just checked my research links and one at:
http://www.animalvoice.com/

explains that infrasound does travel long distances in the outdoors, in fact this is one of the reasons animals use infrasound

-- another really interesting reason is for healing bones and tendons, check out the "Cats Purr" in their Bioacostics Research tab.

They say:

"INFRASOUND
Infrasounds are sounds below the human range of hearing, technically 20Hz, but most adults will be hard pressed to hear anything below 40 Hz. Your average sub-woofer speaker goes down only to 25-40 Hz. However, at high enough amplitude (very loud) you can feel infrasound, it will shake you. Anyone that has ever watched the space shuttle take off will tell you that it shook the ground and rattled windows, that is infrasound! Infrasound is a long, sound wave. It can pass through forests, buildings and even mountains. For example, the space shuttle taking off creates a very loud sound pressure wave of .02Hz (very, very low). It takes @20 minutes for this sound to reach Langley Air Force Base in Virginia, from Kennedy in Florida. This sound wave will pass through everything on its way, and will continue around the earth until it finally dissipates due to attenuation (lessening of the amplitude of the signal over distance/time).

Animals that generate infrasound include elephants, whales, alligators, hippos, rhinos, giraffe, lions, okapi, tigers, and several birds. The common thought used to be that only large animals could generate infrasounds, we now know that smaller animals do produce infrasound and there are probably many more we do not know of.The animals that can detect infrasound either seismically (through the ground), atmospherically (through the air) or underwater, are too numerous to mention. Fauna Communications specializes in studying this type of sound."

[emphasis not in original]

My point is that since "smaller animals" make infrasound ( and the unmentioned reason is that they do this for communication, as do the elephants and tigers, etc.) wouldn't 300 watts be enough using the TST429 infrasonic transducer on a piece of 3/4" plywood (as specified by the maker of the trasducer) actually cause the sound to be felt 6 or 7 feet away, in a partial outdoor space. I am thinking more likely than not likely.

IMO, I think this would work well.

treitz3

You could always get a recording of Alvin and the Chipmunks and play it in a continuous loop outside on the front porch using Bose speakers adjusting the bass all the way down and the treble all the way up with a really cheap receiver that's activated by a motion detector and then spend the rest of the dough on improving your sound inside.

RuSsMaN

All you need is a good 50 watt amp, a couple Cobraflex horns with Atlas drivers, and run that Vietnamese lady talking over and over like they did in Apocalypse Now.......squak box style......

SKsolutions

What about a special variance to build a fence or gate?

The city should accommodate if their gig is affecting your business.
I worked for a non-profit and the shelter was across the street, made getting to the front door interesting.
I would also contact the facility and tell them that under the advice of counsel, you are calling them to find a suitable remedy. If you get nowhere, get a friend to dress up like a vagrant, and chase him around with a running chainsaw, while shouting expletives regarding what you will do if you ever catch one of them hanging around again.

Serendipity

So - how is the project going so far?

beardog03

get a paint ball gun...

honda cber

disrupter,
any luck with the project? curious to know how you made out.
a

honda cber

uh oh.

a