Eckel Industries Inc. designs, fabricates and installs full and hemi-anechoic chambers to precise specifications for government laboratories, industrial concerns, and leading universities.
Fully integrated systems and designs include requirements such as isolated floors, light and power connections, ventilation, temperature and humidity control, instrumentation sleeves, control supports, working floors, and single and double sound doors.
Anechoic Chambers are echo-free enclosures with a sound energy absorption level of 99% to 100%, or a reflected sound pressure level of 10% or less. The frequency at which the energy absorption drops below 99%, or the pressure reflection exceeds 10%, is known as the low-frequency cut-off.
Sound absorption is obtained by lining the walls, ceilings, and floor with wedges or other sound absorbing elements or SuperSoft panels, depending on performance level required and cut-off desired.
FULL ANECHOIC CHAMBERS are engineered acoustical structures that simulate "free field" conditions, where the walls, floor or ceiling absorb 99% to 100% of the incident sound's energy. These chambers are constructed with noise attenuating outer structures of masonry or modular panels and have all interior surfaces lined with "anechoic wedges". The First chamber built in the United States was constructed at Harvard University's Electro Acoustics Laboratory under the direction of Leo Beranek in 1942-43. He and his engineers determined the best absorbing unit to be the linear wedge structure, "the anechoic wedge" made from 3.5 PSF fiberglass, after testing many different structures and materials. Oliver Eckel worked with Beranek at that time. He was the general manager and senior engineer of the company that fabricated and installed the wedge units.
Full anechoic chambers have working floors constructed of spring tension cable mesh or grating floor sections to support heavy test specimens above the floor wedges. These chambers are used for sound measurements in a wide variety of research and development applications such as analysis of directivity patterns of noise for loudspeakers, microphones and electrical components, telecommunication equipments, as well as, auditory research to mention just a few. The anechoic chamber at Orfield laboratory in Minneapolis, MN is NIST certificate and was designed engineered and constructed by Eckel Industries. This chamber is "The quietest place on earth" according to the Guinness Book or World Records 2005. The ambient noise level was measured at -9.4dBA (typical chamber run 15 - 20 dBA).
HEMI-ANECHOIC CHAMBERS have acoustical treatment on the walls and ceiling only and hard floors with no acoustical treatment. The solid floor of the hemi-anechoic chamber is common for testing large and heavy equipment such as automobiles, construction equipment ATV's or white goods such as refrigerators, washers and dryers, where the normal mode of operation is over a reflective plane such as a floor or hard road surface. Both Hemi-anechoic and Full anechoic chambers can be used in construction with reverberation rooms for transmission loss studies for car body panels and even the noise attenuating characteristics of aircraft fuselage construction.
Please use our Test Chamber Checklist to request addtional information specific to your needs.
