A parabolic dish reflects the sound waves from a larger area down to a small point, so using a parabolic dish with an attached microphone can allow you to listen to faint sounds at a great distance. When looking for a parabolic dish to be the base for your sound collector, utilise materials akin to a flattened bowl or a satellite dish rather than a half-sphere. A wok's size and shape make it a good candidate for your project.
Remove the handles from your wok. Drill out or cut off the handles and smooth out the result.
Level your wok by setting it on a small bowl. Lay your level across the wok in one direction and align it to level. Rotate the level 90 degrees and align it to level again. Use the eyedropper to drop some food colouring into the bottom of the wok. Where it settles is the precise centre of the wok. Mark that spot with a pencil.
Drill a hole through the marked centre of the wok large enough to accommodate your threaded rod. Slide the rod through the hole until it's about halfway in. Attach washers and nuts on either side of the rod to secure it to the wok.
Cut a slit in the neoprene disk large enough for the microphone to pass through and hold snugly in place. Fit the wire ends of the lampshade frame into the lamp mount and then push the neoprene disk into the lamp mount so it holds the lampshade frame in place.
Place one nut and washer on the threaded rod inside the bowl of the wok. Pass the washer-end of the lampshade over the threaded rod and then slide another washer and nut on the rod after the lampshade. Tighten the nuts to hold the microphone mount in place. Slide the microphone through the slit in the neoprene disk.
Connect the outside end of the threaded rod to your mounting bracket of choice. If you wish to have a handheld dish, slide the handlebar cover over the threaded rod for a convenient grip. If you wish to mount the dish, use the mounting brackets to attach the threaded rod to a tripod mount and then set the dish on a tripod for steady listening.
Things you need
- Food colouring
- Parabolic dish
- 15-inch threaded metal rod, washers and nuts included
- 5-inch diameter circular hanging lamp
- 5-inch diameter Neoprene disk
- Small lampshade frame with washer mount and three 4-inch tall wire arms
- Mounting brackets and screws
- Bicycle handlebar cover
- Tripod mount and tripod