| 摘要 |
<p>The board has three sheets (1, 2, 3), which extend over a substantial part of the entire surface of the soundboard. The two outer sheets, each containing a layer of long fibres, are embedded in a carrier material, and the middle sheet has a lower density than the two outer sheets. The long fibres of the two outer sheets are disposed parallel to one another in the respective sheet and extend at acute angles between 2 and 25 degree.</p> |
