The second-level soundproofing system. The most common and demanded system. It is recommended for use in multi-apartment residential buildings of enhanced comfort, 5 star hotels, hospitals, health centres, etc. The system ensures the best soundproofing effect against airborne noise and significantly reduces structure-borne noises. The main system elements are viscoelastic membranes Tecsound. Airborne sound insulation index Rw = 60-64 dB