'Hydra AD'

Single & Double Acoustic Steel Hinged Door.

To maximise sound insulation, it is necessary to minimise vibrations in and through a structure and hence minimise transmission. The degree of sound transmission will depend on a number of factors: mass, stiffness and insulation.

Advanced Acoustic Doors are manufactured from steel, providing greater mass than other raw materials. Through extensive research our core materials and combinations have been developed to improve both insulation and stiffness.

Many sound insulation systems fail to meet the design specification due to the fact that although the insulating structure performs satisfactorily it is not perfectly sealed to the surrounding structure. A very small air gap can allow a very large amount of sound energy to be transmitted and hence cause an acoustic 'short-circuit'.

For example, a 5mm gap at the bottom of a door capable of reducing sound transmission by 45dB would result in an overall sound reduction of only 25dB. In other words 250 times as much sound energy is transmitted underneath the door as through the door. Even the slightest gap can materially reduce the sound attenuation performance of a structure and it is extremely important to consider not only the design of the door, but also the installation of the door and the design of the wall.

The sound insulation performance can be described over a range of frequencies as the Sound Reduction Index in dB. Advanced have developed a range of Acoustic Doors providing a variety of sound reduction capabilities.

Type Rw Performance Description

AD1 20-25 Minimal Speech clearly audible.

AD2 25-30 Average Normal speech understod

30-35 Loud speech understood.

AD3 35-40 Good Loud speech audible but not intelligible.

AD4 40-45 Very Good Loud speech just detectable.

AD5 45-50 Excellent Loud speech barley audible.