APPENDIX

Short and wide bows behave as an apparent shortening and widening of the bore. You can picture this shortening to yourself as if the acoustical central axis takes an inside bend and therefore shortens somewhat. Next, the volume of the bow is compressed on to this shorter length, which amounts to the same as if the bow would be wider.

  • The first result of the shortening is that tube parts above and below the bow (to the left and to the right in the profile) acoustically are closer to one another than as measured along the central axis: if we imagine the part of the profile to the left of the bow to be shifted toward the right (A shifts to A'), we see that this part is narrowed as compared to the standard cone
  • The second result of the shortening is that conicity in the bow acts as if greater than it is in the standard cone.
  • The consequence of the widening (the volume of the bow is compressed on a shorter length) is that the bore profile behaves as indicated by the black curved line
  • acoustical effects of a short and wide bow

    The magnitude of these effects depends on the dimensions of the bow and should be compensated for. Especially for bows in the upper part of an instrument, which play a role in both registers, it is importent for the tuning of the registers among one another that this compensation is designed in a correct manner.




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