Unwanted audible sound and noise disturbances experienced within the automotive cabin, such as traffic and wind, are located in the 1,000 to 4,000 Hz range. S-LEC™ Sound Acoustic Film improves sound transmission loss of these noises by 10dB compared to standard PVB interlayer film. S-Lec Film’s superior dampening performance controls low frequency vibration energy from the engine (100 to 500Hz) that resonates across the windshield.