# LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympics.



## dirtyfacedan (Nov 10, 2009)

The Vancouver cops have recently purchased at least one LRAD system, just in time for the winter fucking games. I was wondering if anyone has ever dealt with this. It was used at the Pittsburgh anti g-20 meetings a couple months ago as well. I'm sure if you ever wanted to piss off a large group of people and agitate them to action, this must be the way. They say they just want to use it as a PA system, but we all know the cops have a tendency to abuse things like this. I'm sure there are some now deaf puppies running around very disoriented in the Lower East side of Vancouver as i type this.


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## Beyond The Sun (Nov 10, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

I haven't encountered it, but I have done a little research into it. According to this site HowStuffWorks "How LRAD Works" "some people have questioned the LRAD's effectiveness, since wearing simple ear protection can render it useless." So bring earplugs? Also, it can potentially cause permanent damage. So yeah, bring earplugs. 
I have a very limited understanding of how sound works, and I don't know if anyone on here could answer this, but would it be possible to create something to counter the sound waves and cancel them out? I dunno. I'm going to see if I can dig up anything else on that.


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## compass (Nov 10, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*



Beyond The Sun said:


> I have a very limited understanding of how sound works, and I don't know if anyone on here could answer this, but would it be possible to create something to counter the sound waves and cancel them out? I dunno. I'm going to see if I can dig up anything else on that.



From Wikipedia: "Countermeasures may include the use of passive hearing protection (earplugs, headsets), which may bring the sound down to ineffective levels. In addition, sound could be reflected from a solid surface, and redirected back to the originator."

What I'm wondering about is if you knew what frequency they were using, could you transmit sound waves 180 degrees out of phase, effectively neutralizing it? I know this is theoretically true about sound, but I don't know much at all about the technology, so I'm not sure if this is feasible.


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## veggieguy12 (Nov 10, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

Amplified noise-canceling headphones?


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## IBRRHOBO (Nov 10, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

LRAD, albeit new to the civilian market, is pretty old school and quite passive in nature (yeah, some damage, etc.) Its use is pretty arbitrary as well which can lead to some pretty good litigation (applications w/o _mens rea_ established, blah blah)

EHF is probably the NEXGEN device (we had some pretty crude shit in the service almost 20 years ago). See  ELF Definition


This is quite similar to the device we used when I went to war and will be more in line with what true crowd control deals with as that's one of it's nicknames is the Goodbye Effect http://en.wikipedia.org/wiki/Active_Denial_System


LRAD is dissipated quite easily with a good pair of  NIOSH ear protectors found at any Lowe's or Home Depot.


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## finn (Nov 11, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*



compass said:


> From Wikipedia: "Countermeasures may include the use of passive hearing protection (earplugs, headsets), which may bring the sound down to ineffective levels. In addition, sound could be reflected from a solid surface, and redirected back to the originator."
> 
> What I'm wondering about is if you knew what frequency they were using, could you transmit sound waves 180 degrees out of phase, effectively neutralizing it? I know this is theoretically true about sound, but I don't know much at all about the technology, so I'm not sure if this is feasible.



Well, you can neutralize sound, but it's harder than it seems, since you have to not only get the right frequency and amplitude, you may also have to compensate for phase changes caused by sound reflective surfaces depending on the environment. But yup, earplugs are the way to go, nice and simple and most of us should have them.


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## Monkeywrench (Nov 11, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

I experience the LRAD in Pittsburgh and I'm going to tell you that it's one of the most fucking obnoxious sounds you can ever hear. It's like a shrill, blaring car alarm that you can feel in your bowels if you're too close. 

At a certain rage, if shit hits the fan and the police decide to amp it up--I know for a fact that earplugs won't do shit.


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## yarn and glue (Nov 28, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

I stared down the LRAD every day in Pittsburgh. There are a few things to know about it:

1) It's essentially got a volume knob, and generally they won't turn the full force on civilian demonstrators. Though it can be used, at the far end of the spectrum, to inflict overwhelming pain on subjects, this is a crucial moment for the LRAD (which was, until PGH, never before used in civilian applications), and unnecessary use of force would draw unwanted attention.

2) The LRAD's cone of influence seems to me highly directional. Now, if you're outside of that cone, it will still be incredibly loud -- but if you can avoid getting the dish pointed directly at you, you can probably avoid the gurgly stomach-feeling Monkeywrench mentioned. Save your constitution for the tear gas.

3) Ear plugs may not work the way you hope they will -- you'll still hear the chief of Pittsburgh Police sharing a recorded message in both English and Spanish, for instance -- but they CAN reduce the damage your own personal set of ears receives. Remember, earplugs are a good idea; even if it seems like the noise level with them in is still uncomfortable, they might be the low-tech failsafe between you and lasting ear damage.

4) Other possible countermeasures: It's commonly known that sound waves bounce off solid surfaces and back to the originating point. The basic way to enact this principle is to engage the LRAD anywhere but out in the open, if you can choose your turf. I also have a vision of a concave panel being hoisted by protestors to bounce sound back to the LRAD operator, but the practical difficulties of deploying something like that at a rally seem to suggest finding a more effective countermeasure, such as:

5) EMP (ElectroMagnetic Pulse) LRAD runs on generators. Need I say more? Will cost thousands of dollars to buy or you can make your own. For legal reasons, I do not recommend trying this at home, or around friends with pacemakers.


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## yarn and glue (Nov 28, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

Also, read up on the science behind it:

http://science.howstuffworks.com/lrad1.htm


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## Gypsybones (Nov 28, 2009)

*LRAD, (Long Range Acoustic Device), VAncouver Police have it, just in time for the winter olympi*

yeah to hell with that thing. 
sorry if this is off topic but the Russians are gonna be next to imposable to beat this year in hockey. Malkin, Ovechkin! unstoppable


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