How to Build a Shield From a Sonic Cannon With Your Own Hands
In recent weeks, police departments across the country have used so-called “sound cannons” to contain and disperse crowds of protesters . Officially known as Long Range Acoustic Devices, or LRAD, these loudspeakers are essentially sonic weapons that allow law enforcement agencies to broadcast high-frequency sound at painful loudness and precise direction over long distances.
LRAD can cause headaches, nausea, and dizziness – up to and including permanent hearing loss.
The folks at Dave & Gabe , a Brooklyn-based setup studio, recently built and tested a homemade LRAD shield that’s portable enough to carry around to a protest. They put together a complete guide with instructions and test results, but here are the basics.
You will need the following:
- 3 ” pine slats or 2×4
- 5/8 “drywall or 1/2″ plywood or 1/2 “acrylic
- 3/4 “channel
- Insulation (denim, rock wool or fiberglass)
- Drill + screws (depending on material)
You will be using pine slats or 2×4 planks to create the frame – the instructions recommend 26 “wide by 34” high to balance portability and practicality. The model includes center beams in addition to the outer frame.
Once you’ve built the frame, install the insulation (trimmed on both sides to the same size) and then drywall or acrylic. You will also want to drill a 3/4 ” hole in the bottom of the frame to run a monopod channel through it.
The D&G model, which uses clear acrylic as the outer layer, also has a cutout in insulation for viewing.
Keep in mind that this is not a perfect solution that guarantees 100% LRAD protection. D&G instructions note that larger devices mounted high up will not be blocked by the screen. You should also carry earplugs and ear protection with you at all times if you are at risk of colliding with an acoustic weapon.