Build Your Own Anechoic Chamber

For professional-level sound recording, you’ll need professional-level equipment. Microphones and mixing gear are the obvious necessities, as well as a good computer with the right software on it. But once you have those things covered, you’ll also need a place to record. Without a good acoustic space, you’ll have all kinds of reflections and artefacts in your sound recordings, and if you can’t rent a studio you can always build your anechoic chamber.

While it is possible to carpet the walls of a room or randomly glue egg crate foam to your walls, [Tech Ingredients] tests some homemade panels of various shapes, sizes, and materials against commercially available solutions. To do this he uses a special enclosed speaker pointed at the material, and a microphone to measure the sound reflections. The tests show promising results for the homemade acoustic-absorbing panels, at a fraction of the cost of ready-made panels.

From there, we are shown how to make and assemble these panels in order to get the best performance from them. When dealing with acoustics, even the glue used to hold everything together can change the properties of the materials. We also see a few other cost saving methods in construction that can help when building the panels themselves as well. And, while this build focuses on acoustic anechoic chambers, don’t forget that there are anechoic chambers for electromagnetic radiation that use the same principles as well.

Thanks to [jafinch78] for the tip!

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Airport Land Art is (Acoustic) Baffling

According to an article in the Smithsonian magazine, these geometrically arranged hills aren’t landing signs for extra-terrestrials, but instead effectively sound baffles worked into the ground behind a runway at Amsterdam’s Schipol airport.

Photo by Alexis Glass, via Wikipedia
Photo by Alexis Glass, via Wikipedia

The 80 acres of hills and valleys are called the Buitenschot ‘land art park’ and supposedly reduce noise in the nearby neighborhood by around 50%. They work by sending the reflections in random directions that would otherwise skip off of the ground, just like anti-echo baffles in a sound studio. A nice touch for the local residents, they also contain jogging trails.

People have made land art before — we particularly like Spiral Jetty in the Great Salt Lake — but as far as we know this is the first land art “piece” that’s also functional.

Beauty is in the eye of the beholder, of course. Unfortunately, as the Smithsonian notes, nobody is beholding it. Because Buitenschot aims to diffuse the takeoff noise coming out of the rear of the planes, they are always flying away from it; passengers don’t get to see it from the air.