Features:
3-Layer Materials
In our latest generation of 3-layer composite (Patent Pending), the dense acoustic barrier layer has been 'suspended' away from the substrate in the centre of the acoustic foam. The construction layering is like this: (noise source) acoustic foam -> acoustic barrier -> acoustic foam (then the substrate, which is usually a metal sheet panel).
Sound energy first hits the upper foam surface, which is similar to the 2-layer construction, in that it is a low-reflective soundproofing material that is particularly effective at absorbing high frequencies. The sound energy then encounters the central suspended barrier layer, which is decoupled from the substrate. This high-density high-mass layer acts as an acoustic barrier mass to the transmission of energy through the material. The 3rd layer of foam acts to suspend the barrier layer a small distance away from the substrate. We have found from both small scale impedance tube and larger scale reverberation chamber acoustic tests that the 'suspended' central acoustic barrier effectively increases the absorption of low frequency noise (< 1khz). this='mass-spring effect', where low frequency energy is absorbed by the sound 'moving' the layer when it is excited by certain resonant frequencies.
The 3-layer materials are attached by a supported self-adhesive directly to the substrate, and have a damping effect on panel vibrations. (Hit the side of your PC once fitted, and you will hear a dull 'thud' sound).
The 3-layer materials in the AcoustiPack kit range are 7mm thick. We also manufacture these composites up to 13mm thickness (and over if required ) for manufactures and OEMs. For example, they have been very successfully used in servers and server cabinets, and tested by many different organizations all over the world since they were first developed.