Traditionally, headliners for improved acoustics have concentrated on absorbing sound generated within the vehicle. In-car testing has shown that the most effective constructions combine interior noise absorption with dampening of roof vibration. Technology has been developed which provides better dampening of roof vibration than the combination of a traditional headliner and dampening pad. Benefits of eliminating a separate dampening pad include guaranteed roof contact for long term roof dampening and the elimination of a separate labor intensive operation.
In-car acoustic excitation and structural excitation tests demonstrated the benefit of this technology. Road testing in a Mercury Topaz showed that, while the full benefit of this technology may not be fully realized in all vehicles, the good acoustical performance of fiberglass headliners can be matched or exceeded with FSL headliner designs which offer more styling flexibility and toughness during installation. This technology can be used to tailor headliners for the cost performance required for various car sizes and models.
This paper discusses the details of 1) comparative noise levels recorded during acoustic and structural excitation tests, and 2) comparative noise levels recorded during Topaz road tests.