LRADs and Sound Cannons Are NOT Safe. Here's How To Minimize Their Effects.

[@airwindows]

Hi Benn! Chris from Airwindows. The reason the thin cardboard is working, is because it's rigid mass. It's like watercolor paper: the more metallic the 'rattle' of the paper, the more it will protect you. Foamcore is a little bit softer, and the acoustic foam is softer still. Absorption means nothing here at these amplitudes, but they're so directional that reflection is very effective. Bear in mind that if you are reflecting this attack, any person between you and the attack is getting doubly attacked (no bueno!). Be careful, and be safe! and thank you!

[@difflocktwo]

What about some thin plastic film stretched tight like a drum skin? Or wet fabric?

[@laurenpinschannels]

@@difflocktwo I'd bet against both based on benn's pinned comment - we were debating in the comments whether gun range ear protection or earplugs would help and the answer seems to be a solid "no". fabric, especially, is porous, and remember that this is a *very very very* loud sound. You're trying to make the paper/cardboard act as a mirror for sound, so it needs to be rigid across its surface at a small scale. It has to be able to reflect the sound solidly, absorbing it seems to be a non-starter.

[@airwindows]

@@laurenpinschannels You would be right. The material's got to be rigid and have at least a little mass. Film might be stretched tight but it's also got to have mass, and fabric is something Benn effectively tried: it'd be no different than foam, I think. As for absorbing it: I'm sure the foam, cloth etc. can absorb 6, even 12 db in these thicknesses (not against a backing). Subtract that from 160 db and you're still in very serious trouble.

[@nothanksyoutube]

So plexiglass? Effective? Could have a dual purpose of being see through.

[@BennJordan]

Yeah, the closest (early) conclusion I could come to, understanding a bit of the math at play, is that the paper or cardboard has a perfect combination of "rattle" and deflection. Too much rattle just turns your shield into a loudspeaker (I had tried a kick drum skin and this was exactly what I encountered), too much deflection just hits another protester while the waves surround the shield and hit you at the same time. You're almost literally dealing with finding a sweet spot between sound isolation and stopping a weak FM signal. But most importantly it needs to be something that doesn't interfere with the protest itself (I've heard a lot of creative suggestions of things that nobody in their right mind would carry around lol).

[@torikellett3782]

I just want to add some notes about hearing loss that were glossed over in the video (I understand it wasn't the main focus). It's not the perforation/'burst' of your ear drum that's the problem. It's very likely that exposure to this will leave your tympanic membrane undamaged; it's the hair cells of the cochlea in the inner ear that are traumatized by loud noises, and this WILL lead to permanent hearing loss. Also, an eardrum perforation will heal, but the hair cells of the cochlear will not ever recover.

[@kristalmckinstry2095]

UPDATE: (from someone who invented phase convergence acoustic holography for communications back in '93.) One of the links someone posted included a breakdown of the model 300 which does not appear to be low ultrasound, let alone high ultrasound, but I'm still convinced the top models are. This post only regards high end ultrasound and high ultrasound models, not anything visually resembling megaphones. I've done my best to research and 'theoretically' devise an affordable defense. I have no means of testing if this actually works. I don't recommend finding out. The principle of this design is to scatter high ultrasound enroute before it can phase converge at the target to become audible or low ultrasound. As such it is meant to be held an arms length away. The concept is similar to stealth coatings, except acoustic, not radio. INSTRUCTIONS: Outer layer (preferably black silicon oxide (wet/dry)) facing abrasive side outward of P40 coarse sandpaper for 19khz scattering. Spray that with a very light misting of thinned white glue and coat with a mix of 1.4-5.6 micron diamond or cerium oxide glass polishing powder for 1-4 mhz scattering. (The P40 also phase staggers when the diamond dust is being hit.) Back with layers of P180-P50 wet/dry also facing outwards for 1-4mhz diffraction. Optionally back this with 1/2" squares of aluminum can for general ultrasound reflection reflection and sandpaper vibration resilience. Optionally back this with as close as you can get to 4.25 mm extra thick 'smooth' silicone rubber baking sheet for 19khz 1/4 wave absorption. Finally, optionally mount this all on aluminum street signage for more resilience, impedance, and reflection. * For a quick cheap version, glue a layer of P180 'fine' to the back of your cardboard sign, grit outwards, a lightly tacked layer of P40 'coarse', grit out, on top of that, and turn your sign around to use. Another way of going about this which would disperse even more is to cover a board with acoustic ceiling popcorn (or even actual popcorn), spray that with glue, and coat with a single mixture of all the grits cited. * If you desire a fun art project, look up origami herringbone tessalation on KZbin, and substitute glossy poster paper. The fold dimensions should be decent for devices using only low ultrasound. An aluminum road sign banged to all hell with a variety of ball peen hammers would likely work much better though. * Someone here commented on Tartini Tones aka ring modulation, sum and difference of frequencies. That has existed where low ultrasound 16khz + 16002 hz can create a difference of 2 hz, a beating in your ear. Conceivably it could be used with high ultrasound to create low ultrasound, but it's an obsolete system, not very powerful. A phased convergence sweep could easily deliver 10-100 times as much energy, yet is much tougher to block. It can pass around obstacles in a manner the former can not and meets less air dissipation. I just saw a a breakdown of the 300 which had 2 folded horns. That might be a ring-mod model. * As to why non-glossy side works better, my theory is that glossy merely reflects and transmits through, whereas non-glossy then glossy actually traps resonant sound waves bouncing back through (the paper being the perfect thickness for 1-4mhz waves), and then additionally creates some anti-sound. * I am taking down my explanation. There remains some possibility that I'm actually still quite ahead of the weapon mfgr's and just made a big mistake giving them ideas. However given that G has a product for targeted communications, and that one product i read about elsewhere at least involved an oscillator delayed sweep across the array, I don't think i've handed them any worse than they already know about. Hopefully you read it, plus all the fun stuff you may wish to look into. * 'For some reason' I am not receiving any notifications regarding my posts here, though people were responding to me.

[@kristalmckinstry2095]

I would recommend doing this on the back of a sign. If it appears you are carrying a shield of any sort , I'd imagine you're going to be all the more a target.

[@teresashinkansen9402]

The thing is most actual LRADs do not operate on ultrasound frequencies, they are just extremely powerful loudspeakers with some directionality, reason why is difficult to shield against them, if they used ultrasound any stiff flat object would bounce be beam right back.

[@kristalmckinstry2095]

@@teresashinkansen9402 I've only looked into the ultrasound type. I agree that sandpaper scattering would be absolutely useless against loudspeakers. However these days it's even worse, they have moved on from ultrasound phased arrays to microwave phased arrays for crowd control. I'm not really in the mood to even contemplate that further.

[@KRAFTWERK2K6]

The problem are those kind of soundweapons that use your skull as the resonator. It's a lot tougher to protect your skullbones from resonating and spreading the sound to your ears. Even covering your ears still makes you hear it because the sound is literally in your head.

[@abbalives]

Yes.

[@dananorth895]

And the resonance still vibrates your brain cells/connections. While the brain has no pain sensor nerves, your skin does. If you feel ANY pain wharsoever that indicates damage! This is LEGAL gasslighting to see how much they can get away with.

[@logicn.reasoning9744]

Sounds like the sound of a top fuel dragster launching. Covering your ears does very little.

[@s.m.4198]

Is there anything you can do to protect yourself from this? I think my neighbor is harassing me using one of these devices.

[@Matt-zp1jn]

Hmmm. Sound weaponizingLRAD devices that use your skull as a resonator in your skull bones?? They already have precursors to help assist this thru the new ear buds devices that sit outside your ear but they resonate the bones/cartilage area of the ear drum area so you can listen to music or audio on your smart phones etc. Add in stronger 5G/bluetooth/wifi and there are possibly the ingredients for something sinister “going wrong” in an electromagnetic lightning, brown out or emp type event and perhaps it would coverup a soundwave digital device attack? Experts have said 5G technology on smart phones is the beginning of military grade 5G attack potential. 😮

[@pinkcashmeres]

It blows my mind how people claim this weapon ‘isn’t that bad’ when people who were exposed to it suffer with permanent hearing damage.

[@soravulpis96]

The thin blue line must use any and all tools available to disperse these agitators

[@pinkcashmeres]

Ace Yes, because unlawfully injuring & even murdering people is definitely gonna get people to shut up. You make no fucking sense.

[@Dampzombieslayer]

Ace The thin blue line should go fuck themselves

[@BlackBunn1e]

@@soravulpis96 The agitators have more of a right to agitate than the thin blue line does to exist. Cops are less important than citizens. End of story.

[@MiriadCalibrumAstar]

thats gaslight and narcisism. "That didn't happen. And if it did, it wasn't that bad. And if it was, that's not a big deal. And if it is, that's not my fault. And if it was, I didn't mean it. And if I did, you deserved it." -The Narcissist's Prayer, by Dayna Craig

[@trannusaran6164]

Christ, police shouldn’t be let anywhere near this kind of thing

[@ezassegai4793]

neither should the rioters

[@neilallison3432]

Most of them probably shouldn't have guns, either. Although, they do seem to have figured out plenty of ways of killing without them.

[@gaytheon]

@@ezassegai4793 what kind of rioters have you seen with access to LRADs?

[@Paradox679]

Meatball joke is that protestors shouldn’t be exposed to the damage they cause

[@QuinnDjinnsQueerGear]

Christopher Morriss wait so now rioters are protesters? No difference? You have fun living in a police state with no freedoms, bootlicker 🥾👅

[@pitchy3890]

It makes me so mad you are getting threatened legally over such an informative and well researched video. Thank you for spreading this news and putting your ears on the line to test these devices for the sake of science!

[@user-wf2fm1yj4k]

had one of these pointed at me when the police raided my house in 2012. Hearing was never the same. They didn't find shit and dropped all charges.

[@jenathent4840]

I’m so sorry this happened to you. Have you had any phycological changes since the incident ?

[@mixedviews3536]

Jenathen T 🤔👀 why do you ask?

[@pinkcashmeres]

That’s fucking horrible. Could you file a lawsuit?

[@evejustamante3908]

I'm SO sorry 🙏🏻🥺 that's absolutely terrible

[@MeatCatCheesyBlaster]

Sue them

[@aethervagrant244]

I have a friend who works in Neuroscience, and they've been experimenting with using ultrasonic frequencies "lasered" at different brain structures, and have induced both temporary and permanent/semipermanent alterations to neural structures and cognitive processes. Like relieving pain, inducing euphoria, feelings of religious revelation, fear and revulsion, dyskenesia...its not just hearing that can be damaged or altered by "sound". These devices are much different than the police variety, but give credence to the idea that in music certain tones or sounds can elicit psychogical changes that are directly neurological in nature and not just based on a cultural bias as to what sounds sad or happy or dramatic et al.

[@IanGrams]

Whoa that's fascinating. Thanks for sharing! In undergrad I learned about Transcranial Magnetic Stimulation that can use magnetic fields to influence the brain and cause "virtual lesions" but I didn't realize ultrasound could also have similar influence. I hope that can prove to be a useful noninvasive method of therapy. And here's a brief BBC clip on TMS for those interested: kzbin.info/www/bejne/fH61kIdmorJqhsU

[@aethervagrant244]

@@IanGrams TCMS is what inspired their research, it's still very early and they are still figuring things out, but similar to how psychedelics can be incorporated into therapy with long lasting results, researchers achieved euphoric/divine/expanded consciousness states, that especially combined with therapy and suggestion, induced long lasting cognitive and behavioral changes, all without needing to have direct electrode contact with the brain (though still short distance and long duration)

[@tubulartuber]

what are some keywords to dump into google scholar for this

[@bigclicktvnow]

Can u comment on the ? GHZ frequencies they were experimenting in?

[@abbalives]

Yes I'm an MK-ULTRA expert and this all goes back to experimental psychology that formally began in Germany in around 1940s and all of the (so-called psychologists) were brought into America and given much funding. Hence Tavistock and its creation of social mind control.

[@simonriley765]

These can operate at 160dB? Are you sure that's right? This is totally a weapon if that's the case. For those who don't fully understand how the decibel system works, it's exponential. Benn tested it at 80dB. 80dB to 160dB is 10,000 times louder!

[@BennJordan]

Most police/military models are rated at 159dB. 😕

[@duroxkilo]

160dB is simply insane... that's like the loudness of a gunshot from v close proximity. ----------- not that it really matters but 80 to 160dB is not 10,000 times louder, it's that much more "power"... (it would be about 250 times louder, whatever that means). precisely because our hearing is not linear, we are able to hear sounds that contain acoustic energy over such a large amplitude range (a whisper vs a motorcycle can be a ratio of 1 to 100000 acoustic energy). so, 2X louder corresponds to a 10dB increase in sound pressure level (SPL), meaning from 80 dB to 90dB we would consider/describe the sound twice as loud, to 100dB 4 times as loud, etc. 3dB corresponds to double the power. 1dB is the accepted minimal incremental loudness change we can normally detect. (and yes, it's a bit abstract to describe something twice as loud based on hearing it, but 10dB is the accepted value).

[@jackgrant9301]

Thats as loud as a 9mm pistol, isnt it? Although id say its a lot more damaging because its continuous as opposed to a sort burst.

[@MadelynRusco]

​@@BennJordanjust going to throw this out here...last time i checked "rated" usually means a standard, and in this application its a standard maximum. potentially maximum with normal engineering standards of "rating" is 20% less than actually maximum. in a very general ballpark. potential maximum of a LRAD... who knows until they are tested outside of "normal" operating conditions.

[@astr43us]

They are marketed as weapons

[@_oe_o_e_]

Not “non-lethal” but “less-than-lethal” which sounds a helluva lot less committed to the concept,

[@fluorinegas6944]

I've heard "less-lethal" which is even worse

[@LabGoats]

In regard to rubber bullets, they're "less lethal" but recent studies have shown that'd an understatement. A kid in Austin almost died and has brain damage. People are losing eyes and huge chunks of flesh from their heads and other places.

[@apparently_sonam]

@@LabGoats yes that family is a friend of a friend. Unconscionable. Glad he's still fighting to get better x

[@uzername90]

@@LabGoats I think I read recently that a study showed that 3% of people hit by rubber bullets die, and 15% are permanently maimed.

[@404Anymouse]

Tear gas canisters and flash bangs are "less lethal" but that is compared to freaking *BULLETS*.

[@Kattywampus]

I have heard that thing in Phoenix and did not know it could destroy you like this. I am sending your video to *everybody*. Thank you for saving a lot of people.

[@Dampzombieslayer]

Ace I bet you love the taste of that boot

[@BlackBunn1e]

@@soravulpis96 Stop breathing my air.

[@danielgregory5259]

If you want some help researching sound lasers let me know, happy to lend whatever help

[@PsychicHealingFactoryOutlet]

Daniel Gregory I am currently researching this subject and would appreciate any additional info.

[@uzername90]

I had a question that I posted in a higher subthread, but maybe you could help too. If I were trying to add an anti-LRAD feature to a shield design to protect from ballistics and blunt force (designed using a large rubbermaid lid glued to a foam sleeping pad) would attaching a glossy poster board to the outside of the shield help? Or does the poster board need to be free standing for this to work? Also, if I can attach it to the shield, should I glue the glossy side or the non-glossy side? Would multiple layers of posterboard help at all? Thanks!

[@pc-3083]

I feel like sound would be the best defense..fire with fire. I'm envisioning an app that detects their signal and produces a counter signal via your phone speakers or out your jack to other devices. Just a theory. Someone with more brains and resources than me would need to conduct proof of concept experiments.

[@mlbsoprano2809]

BleepDis a phone speaker is not nearly as directional or powerful as an LRAD

[@bigclicktvnow]

Cool .. any suggestions for getting educated?

[@FerdinandZebua]

LRADs (Long Range Audio Devices) must be banned for use against humans FOR ANY PURPOSE, whether military or civilian or anything in between or beyond. Just like the ban on anti-personnel land mines.

[@soravulpis96]

Ferdinand Zebua or we can continue to allow police use any tactics that they determine effective to maintain law and order. Even live rounds on these agitators that are making America less safe.

[@Dampzombieslayer]

Ace Police aren’t making america safe they are keeping you down

[@FerdinandZebua]

Yeah tactics like making citizens suffer permanent hearing loss, or pushing down 70-year old peaceful lifelong housing activists to crack their skulls open leaving them bleeding on the pavement? You sick, sick monster.

[@firebry23]

😂😂😂😂😂😂😂😂

[@ScuubaSteefe]

I'll never understand the logic of thinking this is OK to use on citizens. if you support using it then you're also placing a target on your back when your political enemy gets a hand on it too. No one benefits from this aside from the companies who make them.

[@abbalives]

The new world order beast system benefits.

[@thebackbuddy748]

Thank you so much to you and your wife for creating this video showing that these weapons exist and cause pain. Too often people stalked and assaulted with these weapons are labeled paranoid and delusional when seeking help in stopping these attacks. Some folks are definitely more humane than others, and you and yours are the top!

[@s.m.4198]

Have you found any solutions? My stalkers have been doing this to me for four years now.

[@k2thah286]

It just hit me about 6 hours later. The take away might just be to DESIGN YOUR PROTEST SIGN with the possibility that you can use it to shield you temporarily, and give you enough time to regroup.Those are just my thoughts. Shreddward sent me.

[@jubjuber1]

yes! and the other is using a Rubbermaid lid with a glued on camping sleep pad as a cheap light shield for rubber rounds (also made into a 'sign' )

[@DLLL598]

Had no intention of learning about LRADS today, but glad I did.

[@SuperElo2008]

It's absurd that you needed to make this. This is mad.

[@screamerboy100]

You sir, are so badass for making this video. I’ve been researching this and am no longer that worried anymore!

[@happypathway5418]

Benn I've watched a lot of your videos on modular synthesis and other sound design topics. Totally awesome how you took your knowledge and used it for much needed activism and protection of the people. Mad props!!!

[@fmmh]

Hi benn, amazing video and very needed at this time! I am physics graduate and I think I can explain why the paper works and the foam doesn't. The purpose of acoustic foam is to ABSORB sound, this means that while a sound wave passes through it, its amplitude gets decreased (because foam is a very dispersive material, meaning it has a bunch of holes in which sounds bounce around a lot), this works really well for lower volume outputs, but LRADs are VERY loud as you explained, therefore the foam does reduce a bit the volume but not much else. The paper on the other hand is solid and smooth, therefore it bounces the sound wave (or at least a bug chunk of it) right back! Exactly like if you were in a big hall with smooth walls, there is a bunch of reverberation, the paper acts like a "mirror" for sound waves!

[@mmm5030]

Not Me Would a shield wall Perhaps reflect the sound back on to the police and turning their own weapon against them?

[@ohxanadu00]

Thank you for your video. A lawsuit is just proof that these things are dangerous and they have something to hide.

[@katebreitenstein6491]

Hi there, the paper probably works because of how its made. All of the other materials you mentioned have a regular recurring structure: fabrics have weaves, foams have a regular plastic structure, metals and "plastic" materials have to line up in order for them to have structural integrity. Paper (and paper-adjacent materials), get their strength from the irregularity of the wood fibers that make it. On an industrial scale, it does have sort of a grain (you can tear it more easily one direction than another) but over-all, paper looks really irregular under a microscope. The fibers probably absorb some of the frequency, reflect, and refract some of it. The rattling (mentioned in prior posts) in the paper is called sizing (like the stuff in starchy shirts). The sizing in industrially made paper tends to be alum and rosin. The "rattlier" the paper, the more sizing is in it. This could be another thing to refract the frequency because its just additional "stuff" in the paper matrix. Lastly, the shininess on paper tends to be kaolin clay, the main ingredient in porcelain china. Glossy mags like to use it because you can use a really thin coat and get it super shiny. What else is porcelain used for? Insulators, because it is really effective at absorbing and diffusing energy because of its super-fine particle structure. So your glossy cardboard is effective because of the thick and irregular structure of the cardboard, probably having a built in sizing element, and a tiny (but still important) coating of clay. If that logic holds, MDF (medium density fiberboard, or low if available), cork, thick handmade papers, thick long-fiber tissue (Japanese tissue) or other materials with an inherently irregular structure like that might work. Also, the Lab Safety Czar in me asks that you find a sound measuring sensor that isn't you, should you continue to do this sort of research. Be safe!

[@OtherM112594]

Thank you for making this video. You’re going to save a lot of peoples’ hearing with this information.

[@squidcaps4308]

No he isn't. This is a fake.. The first clue is the part where he removes background noise with a noise sample loop.. Which is fucking impossible, it will destructively interfere only 50% of the time, the rest of it will be constructive interference, which will amplify noise. This is utter bollocks.

[@IanGrams]

​@@squidcaps4308 what has lead you to believe it only destructively interferes 50% of the time? And if it's 50% destructive and 50% constructive, wouldn't that just cancel out and be overall the same as it started? Regardless, thinking this whole video is fake just because of that one thing seems like jumping to conclusions.

[@nfury8ing]

@@squidcaps4308 It's a good thing you know nothing about sound. Someone might confuse you with an expert. In the future, try not to argue about things you know nothing about when this is -LITERALLY- how you isolate sounds when mixing.

[@alexbarn]

What???

[@IanGrams]

@@Curtarist thank you, though I was already aware of all that. He mentioned the difference of decibels in the video. The goal was to find out what sort of material attenuates focused sound as he also mentioned you still want to get away from it asap. He also tested ear plugs and firing range earmuffs so I'm not sure industrial grade hearing protection would work any better unless there's a type other than those.

[@Jaxzyn]

There is no possible excuse for police to use this on a protest. It's an admission of guilt when they use weapons against peaceful protestors using a few people who may have done some minor infractions as an excuse to attack working class people.

[@therese2301]

"Minor infractions" is an incredible display of historical revision

[@iambadatcomingupwithcomeba2060]

@@therese2301it’s not historical it’s happening right now

[@purp_dog42069]

Make your protester signs out of large pieces of glossy paper

[@FadkinsDiet]

Now cops are going to confiscate all protesters' signs as illegal protection devices.

[@sugarc1rcles]

LRAD's are also being used in Orlando, and Orlando PD has released a statement saying that they are used to relay announcements over long ranges. This is false. The models used by police departments are the same ones that were ruled as being "excessive force". The model in the case against the NYPD using them, where the ruling was made, was the 100x. The one currently in use by the Orlando PD, and likely others, is the 500x. It is made by a company called Genesys, and the use of LRAD's in overseas combat has already been banned. Also, they can effectively be disabled by perforations in general EDIT: Actually i'm pretty sure any perforations at all would disable them. Also, i forgot to mention, the 500x is about 3x as effective as the 100x, the model that was used when these devices were ruled to be excessive force.

[@milsum1443]

hey, thank you. I'm sharing this widely with friends in LA. I appreciate you getting this to us so much.

[@nicosuj]

Is a great, but painfully and risky, demonstration you made. The 15k sound may be worse because is near the cochlea natural frequency (but usually is nearer 10k, but also could that the HS modulation could hit certain harmonics, thou. Intermodulation can give weird peaks sometimes). The higher pitch couldn't say why, but I imagine on how our ears tend more to take HF as positional information, and our brain, when something just doesn't feel right tend to get confused, like having motion when you don't have a point of reference, and also the opposite. Thank you for making this video and putting them as they are: dangerous to everyone. Is the equivalent of pointing lasers to people's eyes, in my ears. Hearing loss is not taken as seriously as it should. Also, in safety terms, 80dB should be safe in 8 hours exposures, but is taken in A ponderation, and also considers that the overall noise is centered on 1K (hence the A ponderation). HF pack quite more energy, and could be harmful even as low as 74 dB, AFAIK

[@KozmykJ]

At least three decades ago I remember Anti Nuclear War - Peace Protestors reporting head pains and feeling Heat in their heads during certain Actions. Some monitoring followed these reports and results suggested beamed micro-waves were being projected. People literally became Hot-Headed and less inclined to restrict themselves to Peaceful protest. I wonder what refinements of That technology have been made in the intervening decades? The 'non-lethal' market has been flourishing apace.

[@gabrielbush1325]

Benn: "If you have some sort of particular political criticism to this video and it makes you want to unsubscribe to my channel, then by all means unsubscribe." Me: *slams that subscribe button*

[@mochimochi6357]

Thank you so much for this! I had no idea that these were a thing and it’s really kind of you to help inform everyone :)

[@StripeyType]

upset I didn't see this last year, but glad the info is out there.

[@Tiirsk]

I read somewhere a Corner reflector could redirect the sounds back at the operator. It wouldn't protect you but it would definitely make the cops taste their own medicine a little. I'd be interested in someone testing the principle.

[@urielohim]

Yeah but anyone in between would be hit double so it would be very dangerous too

[@itsourenity]

Corner reflectors like in bicycle wheel reflectors but just larger?

[@childofthefire]

@@itsourenity you got it

[@Engineer__MD]

Corner cubes will reflect radiation back to their source. You need three surfaces that are highly reflective at 90° angles to each other. The 90° must be fairly precise. The shape is like the inside of a cube. At 10 khz. The wavelength of sound is about 3.5 cm, so you would probably want a corner cube at least 10 cm on a side if not 20. I need to emphasize just how precise the angles need to be for optimal reflection. Probably making them out of some type of metal would be best but anything very rigid and smooth should work. The extreme example of corner cubes is in the optical. When I was worked for NASA m in the 1970s, each Apollo mission that landed on the moon left a corner cube. Now this is optical rather than acoustic, but the physics are essentially identical. NASA periodically checks the distance of Earth to the Moon accurate to a few mm using these corner cubes. There is a good Wikipedia page on corner reflectors. I do need to emphasize that the 90° angle really does matter. Unfortunately, you will only be reflecting back a portion of the energy they are sending out. As far as materials, anything smooth and rigid should work. Tend to aluminum if you have to carry it. Actually I would guess 0.5 mm of aluminum on a fiberglass backing would be the best for function to weight ratio. However, that means you have to be at least literate in the use of fiberglass. There is a definite skill to learning how

[@laurenpinschannels]

I just realized that KZbin constantly recommending me your channel was without me having subscribed, so I guess this video earned my subscription in a sense. really the subscriptions because of all the awesome production tips but not getting injured during activism tips are also extremely great and good

[@shirleyachira7966]

Hi, thanks so much for doing this. I have some on-the-ground requests. Sorry if this seems demanding, its just that you understand and have access to this stuff and most of us don't: 1. For access reasons, can you make a >5 minute version of this, and have written captions like "FOAM DOES NOT WORK," "THIN PAPER WORKS WELL AT 15K HZ" etc. A lot of rumors are flying, some based on this video, some that are misinterpretations of what you've presented here. This info is awesome and its great to watch yall nerd out in comments, but a lot of us just need quick info and not a technical explanation of how the LRAD works. 2. From the video, it SEEMS like commonly used protest sign materials would work well. The kind of paper you used successfully isn't as easy to buy especially right now, but cardboard packaging is everywhere. There's also some talk online about making corner reflectors (twitter.com/LikeClocktwerk/status/1268794692855951360), maybe out of cardboard. Maybe that's dumb, I'm not a sound tech so I don't know. Can you test out the following, flat, and arranged as corner reflectors (which one could pre-cut): *glossy food packaging cardboard (eg. cereal and beer boxes) *corrugated fiberboard (regular moving-box cardboard. w/ wavy layer encased in two flat layers) *waxed cardboard (used for produce, should be some behind any food store) *regular cardboard w/ mylar pasted on one side, if that seems relevant 3. If you or anyone with the technical ability is up to it, it would be a good idea to solicit and compile on-the-ground experiences trying these different methods of deflecting LRADs. 4. Can't locate the comment but someone said that the ones they're using are at 22,000 hz or something, thoughts? 5. In the video you say the matte side is more effective than the glossy, but the summary says the opposite. Just tryin to clarify. Thank you so much!

[@Slbeetle]

Thanks. I need to tell you that people like you make the world better.

[@kristalmckinstry2095]

Benn: Try sandpaper of different grits (and please find my other posts describing how acoustic holography works). A course 36 grit is likely ideal (rough guess), but it would depend on the mhz of the transducers used. Multiple layers should work even better. Tightly wrinkled then flattened aluminum foil might help. Silicone rubber sheets at 1/4 wavelength thickness should help. However keep in mind we are trying to block two different frequencies, the constituent 1-4mhz and the phase convergent 19khz. If you really wanted go all out, two top layers of 36 grit sandpaper, a layer of aluminum squares in any size from 1/4" to 1" at 0.025-0.1 mm thick (depending on 1-4 mhz device), a silicone rubber sheet preferably 4.25 mm thick (for the low ultrasound 1/4 wave, and finally a thick say 3mm aluminum street sign board. You can not remove sound, only transduce it to other frequencies or energy types. Come to think of it i once designed a car muffler material which had a thin sheet of spring metal cut into a grid of v-cuts to create harmonica reeds. It's purpose was to convert audible frequency exhaust noise into ultrasound frequency people couldn't hear with as little impedance as possible. Ok, just read about the gag order and got it now. I have a lot to say towards your defense in a comment there as well.

[@abbalives]

Would you be able to message me thru my about page or channel comments and help me block some low frequency sound weapons I'm hearing in the forest behind my house for the past couple years?

[@8thlvlMage]

Just going to point out 36 grit being a rough guess is a wonderful pun. I hope it was intentional!

[@kristalmckinstry2095]

@@8thlvlMage It was indeed. 36 grit did turn out to be pretty close for one of the components. If mhz types are involved though, making your own sandpaper with a spray-bottle mist of highly thinned white glue and 1.4-5.6 micron glass polishing powder, directly on the rough surface of 40 grit. Fresh DESIGN UPDATES now being posted.

[@Em4gdn1m]

Wait, holy shit you're Benn Jordan??!?!? I LOVE your work. I've always wanted to see you live. If touring ever happens again, please come to SLC. I would love to meet you. I've been listening to your stuff since Red Extension of Me and the SICKEST bass line I have ever heard on An External Frost. You are incredible. Keep up everything you do.

[@heldermiguelmenor6502]

right on brother. power to the people

[@abramtreadwell722]

I'm a new subscriber. Great content you've got here. Very informative and entertaining. Also, great idea for a video. Doesn't matter what your political party is, if people have a problem with information then they have an agenda. This is extremely helpful information for anyone. Keep up the great work and I wish you the best.

[@cemreturhan7814]

I can't believe I just found this video. Everyone should see this.

[@diggabledork]

I'm a recent follower of your work coming to this video much after the immediate relevance period. Great content coming from an even better ideological position.

[@RocknRollkat]

It's mazing the amount of research we as humans put in to hurting one another. Bill P

[@JackTheRabbitMusic]

Humans are the worst animals on earth. Hug a rabbit. peace.

[@CrimeEnjoyer]

Thank you for this. Pigs hit my community with a sound cannon tonight and it sucked shit. I had ear plugs in a motorcycle helmet and I still had to give up ground. We are spreading this video around now to help protect ourselves. Thank you.

[@audiokemestry]

These types of weapons should not be used by police on citizens. That being said, I echo what Chris (Airwindows) has said. Given the higher frequencies being used, any materials that are designed to reflect, diffract, and/or diffuse the sound waves would be the ones to use, e.g. a piece of very thin plywood probably would work a even better than than the cardboard as a 'sound shield'. However, the shooting range headphones and earplugs would be the first things that would be in my go bag if I was in the field. Great work.

[@-ius-6502]

Glad you don’t GAF about haters and dividers. Thx for the video keep up the great work. I’m trying to figure out how to protect myself from sound attacks in the future

[@patch6306]

This and your vinyl degassing videos are fascinating! So much potential for new scientific research. Also, glad to see you helping spread some safety news for protestors!!

[@DJPhantomRage]

Frequency resonating the different materials absorbing or deflecting. Like the microwave towers that are just big metal panels. Tuned to the frequency to reflect the signal from mountain top to the next mountain top. (The passive metal panels you once used to see)

[@spartaninvirginia]

"shoot it at the geese" Finally, potentially an effective weapon against the true enemy of mankind. In all seriousness, this is inhumane, regardless of your opinions on the protests. If you cheer for this to be used today, I hope you cheer when it gets used on you.

[@MrMousekitten]

Thank you for your support and service.

[@k.c.simonsen2]

Super cool of you to post this. When the BLM protests were happening my room mate told me about how the police were using Sonic Weapons, and when he explained them to me I was terrified. What a horrifying version of warfare, and it definitely made me much more hesitant to join the protests.

[@projectbirdfeederman5491]

But Sorors love and promotes BLM, so wh would they microwave them?

[@spiralswithinspirals]

We need this more than ever as its being used in my city while i watch remotely.

[@DrAwesomeTBM]

You're doing a great service dude. Much respect.

[@gctypo2838]

Thank you. I didn't hear Seattle listed, but I wouldn't rule out our cops starting to use LRADs in the near future.

[@glenmorrison8080]

I never thought background noise would have a regular enough waveform to allow for inversion cancellation. That demonstration blew my mind.

[@quartzagon8035]

Thank you for doing the work and helping people be safe at protests

[@LexYeen]

Thank you both for this video, those headaches are a small price for this knowledge.

[@spencera4922]

Make your protest signs accordingly. They can be used as your anti-sonic shield if need be.

[@a36452]

ur video is helpful in way you don’t even know. thank you so much. love from orlando!

[@viktorglaken4825]

Hey Brother hey thankful for your witness. Thankyou 👍

[@nanjjypoo1]

Absorption coefficients are a rating of the percentage of sound that will reflect after hitting something like the foam. It gives no account for what will before hand penetrate the given material. The equation for this likely means that even at 80 db a great deal of 2.5-3.5 kHz will pass right through. This is why putting up foam in a studio does almost nothing for acoustic isolation. You need mass. You're best results here were because of surface density which is the best indicator for reflection. Thank you Benn!

[@wyethmiller281]

I wasn't subbed, now I am.

[@natbvm1880]

Same

[@danieldemayo6209]

I was now I’m not!

[@Specopleader]

@@danieldemayo6209 Imagine wanting people to lose hearing for the rest of their lives.

[@Speweythealien]

Same.

[@ModerneArketekt]

Thank you for subjecting yourself to this to deliver this important information

[@jakegerke7188]

Portland, OR protestor here. Rumors went around that an LRAD was going to be deployed, and I think I saw one on top of a police vehicle last night. It wasn't used. Thank you so much for posting this video. I'm terrified at the idea I might lose my hearing just for being in the wrong place at the wrong time, but now I know what to bring with me and how to (hopefully) not harm others while protecting myself.

[@petergamache5368]

... "lose my hearing just for engaging in constitutionally-protected activity" FTFY

[@jakegerke7188]

@Curt Uh, that's one of the first things he pointed out, using a metaphor that it's like putting a shotgun next to your ear and firing it.

[@evilrainbow]

it WAS used and will be again

[@without_wax]

I can't help but wonder how effective a metal mixing bowl, or other items with a parabolic shape, would be at reflecting this bad acoustic juju back...

[@unslept_em]

umbrellas are used at protests too, and they're portable, so I wonder if certain umbrellas might work to stop some of that sound?

[@airwindows]

Flat plane will be better protection. It's about how rigid the material is, so a cookie sheet would also work: anything where moving a millimeter of the material means having to move ALL of it. The shape is less relevant at these frequencies. A parabolic reflector would hurt anybody at the focal point, but that might be very hard to control/aim.

[@laurenpinschannels]

these aren't normal sound waves, they're much more directional than that - think in terms of how you focus the light from a candle on something using a mirror (parabolic shape) vs how you focus the light from a laser using a mirror (just a flat mirror reflects the beam as-is). if you want to diffuse it, a very rigid and rough object may work well, but without more comparison testing like benn did it's hard to be sure how much. he's effectively suggesting a sound mirror.

[@user-ld8ep5qr7m]

@@airwindows Is this related in any way to (one of the) resonant frequencies of the piece of material being used? I might be way off base, but this sort of looks to be related to the way that those flat planar speakers with tiny drivers work. I saw a video on one channel where the guy seemed to be getting good sound from a very small driver attached to a large piece of foam board. Is it possible that this is effectively the inverse process (i.e. the sound is being absorbed and transmitted efficiently throughout the piece of cardboard/paper regardless of point of impact, dispersing the excess energy)?

[@MaxLohMusic]

Seeing that it's already a LASER of sound, a bowl won't do any better than a flat surface. Imagine reflecting a light laser with a parabolic mirror. It would be the same as doing it with a regular mirror because it's already focused to a point.

[@fictorsjsdjs]

Thank you so much for making this video, I really appreciate what you're doing

[@labstan]

been watching your Spotify videos.. but this one right here.. scary-fascinating

[@Jonesy320]

Thanks for keeping this video up and for taking the risks to inform us!

[@neomono2303]

You’re awesome, thanks for this Benn. Quality was fine.

[@encarnacionrivera4468]

You're such a hero for posting this. Much be how they do that direct to skull thing

[@louisgoldberg1755]

Been listening to your music since the 2000s. Having you do these youtube videos is amazing. You definitely cover a range of topics and i really appreciate your content

[@bigdanny420]

thanks for pumping out the video and spitting the facts quick

[@akmv1]

With the glossy paper would layering the paper loosely, like stapling two of the four edges together, work better?

[@AgentLoFi]

There's alot I want to say but in short Thank You, for the info and for the support ✊❤✌

[@rebecca_stone]

Glad you're raising awareness of these. I knew about them being used by special ops, but didn't realise they're being used on the public. If police have them, it won't be long before criminals get hold of them. The first time I ever heard of LRADs were to deter pirates off the Somalian coast - that's a use case I could get behind, given that crew on container ships aren't allowed to use firearms to defend themselves against being boarded by armed pirates. But this is something else, a weapon that invisibly maims your main sense permanently - that's truly scary.

[@squidcatbass]

Thanks for your research! Will go share this

[@ROGUEXUNT]

I saw a video about how to stay away from LRADS on tik tok but they didn’t go into much detail. Thank you for teaching me something new and testing it on your self to shoe us how these machines work !!!

[@aakash9058]

This is a true PSA. Good on you Benn.

[@Havanasyndromev2k]

Currently struggling with Havana syndrome v2k the people doing this to me are John Johnson Lisa Johnson Mallory Johnson they live in socal around Murrieta and Anaheim

[@phuturephunk]

I got linked here from a message board that''s talking about current events and I'm all like...damn you look familiar and then it hit me...YOU'RE THE FLASHBULB!

[@evejustamante3908]

I remember discovering that connection two years ago. I cried. Lol. Benn is a complete genius and must be protected at all costs 🙏🏻💕

[@_f_6957]

Your efforts are appreciated 🙏 thank you so much for this information

[@jslaughterofthesoul4939]

SEATTLE - It’s being touted as a non-lethal crowd control tool by the Seattle Police Department, but Long Range Acoustic Devices, also known as LRADs, are now coming under scrutiny locally and other cities that have deployed the military-grade speakers. Police officials said the LRAD was recently purchased as a non-lethal crowd control tool that was recommended by the mayor’s office after the city received feedback last summer from protesters who said commands from on-scene officers were not clear or loud enough.

[@continuummusic220]

That Like button isn't big enough for how much I appreciate this. Good luck USA, we still love (most of) you.

[@cindyavalos6200]

When I travel I'm gonna start wearing ba shirt that says fuck american government haha

[@brennagera9029]

Omg thank you for doing good work and for you and your wife suffering a headache to help protect others 🖤

[@mysterylime3471]

Fantastic work on this video. LRADs are still certainly dangerous, but understanding them takes away the added fear of a strange and unknown threat. Thank you!

[@ThatGuy-Official]

Sound can be imagined like water flowing. Acoustic foam is like a sponge. Water can flow through the sponge and is only impeded a little once the sponge is saturated. To stop a sound in its tracks, you need something akin to a dam. A rigid barrier that would not transmit vibrations through it would be best. A steel plate coated with rubber on the side you are standing to dampen vibrations would probably work great at blocking sonic weapons.

[@Ed-ty1kr]

"If you don't think I should'nt be helping protestors protect themselves from non-lethat weapons... I don't f-en care!" Ok... subscribed.

[@joelkulesha8284]

Thank you for using your platform to educate and protect people from the horrors the police are putting our people through!

[@monogramadikt5971]

what are the pigs using to protect themselves from it ? is their protective gear commercially available ? can civilians make their own lrad's in the garden shed to use in their own defense ? *or would that be beyond expensive ? lol *i made this comment before the whole video had finished, so some of it you did answer already ;)

[@BennJordan]

They don't typically use protective gear as this is highly directional sound. For example, my wife couldn't even hear the disperse alarm despite it being incredibly loud for me.

[@monogramadikt5971]

@@BennJordan i understand the directional nature of the weapon, i guess they cops using these weapons dont have protection against it because they arent expecting the crowd to retaliate with their own homemade lrad's lol, would be great to see but highly unlikely etc

[@MrFlacco]

✊🏾 you got my like and earned a new subscriber. THEY DONT CARE ABOUT US.

[@PhillipSitbon]

My lifelong tinnitus was made so much worse by LRAD in 2020, even with extensive protection. 15.6kHz 24/7. The police should not be allowed to buy these wespons of war.

[@ConnerCanatsey]

I subscribed explicitly because this was great info to have.

[@adamhorton117]

Super informative man!!!! Thank you for your service!

[@blackham7]

What if all frontline protesters tried to reflect the wave back would that be effective? Strength in numbers?? Agghh I hate this thing

[@everywhirlingplanet]

maybe?? but a lot of the cops' frontlines have plexi shields which i imagine protect them a fair bit

[@-ius-6502]

Thank you for this video. This is exactly why I searched for help protecting against this! Thank you

[@SPetersen4]

Thank you for your service. You're doing good work.

[@JB-bm1to]

Engaging from columbus, Ohio for the KZbin algorithm. Thanks for doing this.

[@jenelaina5665]

Thank you for getting to the conclusion right off the bat. Appreciated. Have you tried a umbrella open and handle towards the source? Wondering if that disperses in a similar way.