Impact of Layer structure in sound insulation

The combination of StratocellWhisper, heavy foil and an additional air cushion results in a particularly high-performance multi-layer system for sound and vibration insulation. This principle uses an extended form of the mass-spring-mass system, which effectively reduces both airborne and structure-borne noise.​
 
Construction principle: mass-spring-mass:
The heavy foil forms the outer "mass" and blocks airborne noise due to its high surface mass.
The Stratocell Whisper acts as a "spring", absorbing sound energy and decoupling mechanical vibrations.
The air cushion reinforces this decoupling as it represents an acoustic resonance layer that attenuates particularly low-frequency waves.​
 
Exemplary layer structure:
Base (sound-repellent side): Heavy foil 3–5 mm, mass weight ≥ 5 kg/m²
Air gap (30–50 mm, double if necessary): acts as a resonant buffer
Stratocell Whisper (40–60 mm): absorbs sound and suppressesreflections.
 
This combination creates an extended range of attenuation:
The air gap lowers the resonance frequency of the system.
The heavy foil prevents sound transmission.
Stratocell Whisper absorbs medium and high frequencies.
Together, all layers can achieve a reduction of over 30 dB, depending on the structure and frequency range.
 
Technical notes:
A 50 mm air gap behind Stratocell Whisperdrastically increases absorption at low frequencies and can lead up to absorption class A (NRC ≈ 1.0).​ If a second cavity is added (e.g. a double layer of air),the sound path lengthens and the acoustic impedance improves again.
 
Application:
This construction is particularly used in areas with a low and broadband sound spectrum:
Soundproofing enclosures for HVAC systems, transformers, BESS systems, and combined heat and power plants
Machine enclosures and enclosures in industrial environments. Acoustic walls and partition systems with requirements for high building acoustic performance.
 
Result:
The additional integration of an air cushion between the heavy-duty film and Stratocell Whisper creates an extremely efficient, broadband soundproofing structure – ideal for applications where there are high requirements for sound insulation combined with effective sound absorption.