Sound Proofing / Insulation: Description and Operation
Low Vibration and Low Noise Body1. General
Effective application of vibration damping and noise suppressant materials reduces engine, wind and road noise.
2. Sound Absorbing and Vibration Damping Materials
^ Foamed urethane sponge and foamed sealing material are applied onto the roof panel and pillars to reduce wind and road noise.
^ A large-size dash inner silencer, dash outer silencer, hood silencer, and engine under cover silencer are used to reduce engine and road noise to improve quietness inside the passenger compartment.
^ Sound absorption materials are used in the engine under cover, front floor under cover, and heat insulator to ensure quieter operation during idling and all driving conditions.
^ In order to minimize grit, water and road noises, the polyethylene plastic fender liners, which are optimally covered with PP (Polypropylene) and polyester felt, are fitted inside the front wheel houses. For the rear wheel houses, SBR (Styrene Butadiene Rubber) and Pet (Polyethylene Terephtalate) plastic fender liners, which are optimally covered with PET felt, are fitted.
^ A material having high sound-shielding property is used for the intermediate film of the laminated glass of the windshield to reduce wind noise.
^ The asphalt sheet has been optimized entirely, in terms of material, thickness, and allocation, in order to reduce the droning sound and road noise.
3. Reducing Wind Noise
^ A foam material is optimally allocated inside the body side members, pillars, and front header in order to reduce the wind noise created by air turbulence.
^ The air turbulence has been eliminated through the optimization of the shape of the hood seal rubber (A- A cross section) and the use of the hood side seal rubber (B - B cross section).
^ Bifacial molding is used around the windshield glass to minimize the offset and the parting width between the windshield glass and the roof. This reduces air turbulence and wind noise (C - C cross section).
^ The door main weatherstrip is made of a material that suffers minimal deterioration in order to reduce aging deterioration. A lip has been added to the base surface of the glass run to reduce wind noise (D - D cross section).
^ A seal rubber is used between the front fender and the side outer to prevent air from blowing through. In addition, a seal rubber is used between the front fender and the front door to eliminate air turbulence. (E - E cross section)
^ Seal rubbers are employed between the front and rear doors to eliminate air turbulence (F - F cross sections).
^ A cap is provided at the top end of the division bar to block the airflow and reduce wind noise (G - G cross section).
4. Door Closing Sound
The door under seal has been changed from the lip type of the previous '06 LS430 to a weatherstrip. Two protrusions are provided below the belt line of the rear weatherstrip. These features restrain the door from fluttering noisily while it is being closed, and instead give it a solid, resounding thump.