What is an Anechoic Chamber?
An Anechoic chamber is a special room used for testing electronic equipment under laboratory conditions. The room is a large box made of sheet metal designed to shield all radio signals from entering. The doors are fitted with special gaskets so that radio waves can’t sneak in through the cracks. The floor has special tiles and the walls are lined with foam rubber pads and cones that are treated to absorb radio energy so that any signals transmitted inside the room cannot leave the room. Because no signals can get in or out of the chamber, engineers can place equipment to be tested and receiving antennas inside it and be assured that any signals picked up by the antenna were generated by the equipment that he or she is testing. This equipment usually is placed on a wooden or plastic table because these materials do not reflect radio signals. This is how engineers determine that one piece of equipment will not interfere with another. For example, no one wants a computer that makes his T
In the simplest terms, it is a chamber designed to be devoid of sonic reflections and resonance, in other words, there is “no” echo. This is the type of environment all AAD loudspeakers are tested in for specified frequency response and is the only way to truly see what a loudspeaker can actually do on its own. AAD is fortunate enough to be one of the very few companies with have the ability or resources to construct one of these rooms. A loudspeaker capable of reaching 30Hz with authority in one of these rooms will be able to generate “frighteningly” deep bass in a typical living room. Another type of test is what is referred to as “in room” frequency response, however, this can be a very misleading specification. In room measuring can cause a loudspeakers frequency response to vary by a much as + or- 18db in the lower frequencies! Unless you happen to have the same listening room as the manufacturer in this case, you will never achieve the same result.
An anechoic chamber is a room with special walls that absorb as much sound as possible. Anechoic means “without echoes”. Sometimes the entire room even rests on shock absorbers, negating any vibration from the rest of the building or the outside. The material covering the walls of an anechoic chamber uses wedge-shaped panels to dissipate as much audio energy as possible before reflecting it away. Their special shape reflects energy into the apex of the wedge, dissipating it as vibrations in the material rather than the air. Anechoic chambers are frequently used for testing microphones, measuring the precise acoustic properties of various instruments, determining exactly how much energy is transferred in electro-acoustic devices, and performing delicate psychoacoustic experiments. The world’s first wedge-based anechoic chamber was built in 1940 on Murray Hill, at Bell Labs in New Jersey. It is encased in more than a meter of concrete to shield it from external noise. Its creators have b
