Improving the Sound Transmission Loss of Wire Harness Pass Throughs

Abstract Improving the Sound Transmission Loss of Wire Harness Pass Throughs For years the NVH community has known that openings in the dash sheet metal, such as holes to pass wire harnesses through, create an acoustical weak point that limits the potential noise reduction of the dash insulation system. These pass throughs can also be a source of water leaks into the vehicle’s interior. With the combustible engine and now electric inverter power plants, the need to seal this area is vital. By molding a lightweight barrier that draws through the fiber/absorber interior decoupler and dash sheet metal which mates to a secondary seal molded into an outer engine dash decoupler, the two opposing molded barriers meet in the engine compartment and compress together forming a seal around the wire harness. This male/female molded seal replaces the conventional snap in grommet and eliminates noise/water leaks. The system Sound Transmission Loss (STL) is equivalent to similarly insulated sheet metal with no holes, increasing sound intelligibility/articulation index in the automotive interior, leading to new levels of occupant comfort and ease of communication. This technology can also be used anywhere in the vehicle where a hole is created in sheet metal and a wire is passed through it (e.g. electric side view mirrors). Authors, James Check Charlie Moritz