QuietStar is a UK anechoic chambers supplier. Anechoic chambers are unique acoustic testing enclosures used for research and development, enabling engineers and scientists to take precise acoustic measurements. Full anechoic (meaning no echo) rooms are lined on all six internal faces with absorbent material to completely absorb sound reflections in all directions. The lack of reflective surfaces in effect offers a complete free-field sphere around the object being evaluated meaning precise acoustic measurements can be taken from all directions. This is particularly important when trying to pinpoint sources of noise from a test subject.
At QuietStar we use wedges in the construction of our anechoic chambers, as these have been proven to absorb sound waves better than flat panels. The more absorption, the better the results for any research and development. Depending on what is being examined in the laboratory, access to the anechoic room may be via an acoustically transparent floor, or hung from wires / harness points located on the inner surfaces. For heavy or bulky items, our chambers can also be designed with a structural steel meshed floor to allow items to be manoeuvred into place with ease. QuietStar has even designed chambers with mechanically retractable floors which allow people to walk around the chamber and set up acoustic experiments and then once they are outside, simply retract the floor to maintain the absorbent finish.
Precision Acoustic Testing
Full anechoic chambers are typically used when a high level of accuracy is required. Such a requirement is usually for evaluating speakers, electronic components and for university research. Other experiments include microphone calibration and development of acoustic monitoring equipment such as sound level meters.
Anechoic Chamber Design
The importance of the design of anechoic chambers is paramount in order to achieve the best possible results once the laboratory is being used. The higher the precision of measurements needed to be made, the higher the amount of sound isolation required to create an acoustic barrier in order to shield any interfering noise or sound waves.
For a high performance chamber, the walls, floor and ceiling would typically be of a double skin construction and utilise anti vibration mounts to de-couple the structure from the host building. Access is typically by back to back high performance acoustic doors lined with wedges on the internal face. Given the nature of the facilities in sealing the inside of the chamber from the outside world, a ventilation system is added to all anechoic chambers giving a silent source of fresh air at all times when in use.
Depending on the size of the anechoic room and the subjects being analysed, the types of wedges used will vary, for example: metal wedges, foam wedges, fibreglass wedges. So the dimensions of the anechoic chamber and the nature of the item being evaluated determine the wedge material used. For smaller chambers that do not require a particularly low cut-off frequency, then flame retardant foam wedges are typically used. The length of the wedge will be determined by the required cut-off frequency looking to be achieved.
If the test subject is larger, or more industrial, then metal clad anechoic wedges are used as they are easy to clean and filled with mineral wool, making them excellent for fire suppression.