| 摘要 |
A microperforated panel absorber (22) comprising a microperforated facing (24), a non-perforated facing (26) and a cellular core structure (28) therebetween; the core structure (28) provides a number of primary cells (33) and a number of secondary cells (37), the secondary cells (37) each provide a reduced cell depth in comparison to the primary cells (33). The number of primary cells (33) and the number of secondary cells (37) ensures that sound absorption at frequencies up to and including the peak frequency is substantially maintained and that the sound absorption at frequencies higher than peak frequency is substantially increased relative to comparable panel absorber in which the secondary cells are effectively replaced by primary cells. |
