Pertaining to bridges

[Richard Brekne]

This thread on Virgils beats, ETD question and related stuff
prompts me to aks a question of our rebuilders who are familiar
with this stuff about bridges.

Also... Weinreich talks about the impedance from the bridge
having three main possible characters. Massy, Springy, and
Resistive. Are these to anydegree something one can design into a
bridge / soundboard  assembly ?

To mind pops up Ron Overs recent postings on the orientation of
bridge wood grain relating to supporting bridge pins... how does
grain orientation fit in (if at all) with impedance charachter ?
For that matter... loose bridge pins themselves.  Would seem to
me that a bridge pin that can give a bit sideways would tend to
effect the whole assembly (for affected notes) in the direction
of being springy...which in turn tend to lend itself towards
pitch drop.

Another thing that I am a bit foggy on here is how exactly does
coupling in more strings exasperate these three conditions ? Take
for example a springy termination. Muting the string would tend
to hold the bridge a bit stiffer right ? .... aslo increasing
impedance seen by the string allowed to vibrate.. and releasing
the muted string then releases that stiffening effect on the
bridge... with a resultant decrease in impedance seen by the
first string.  But this affects only the amount of apparant
bridge impedance... not its character ??? or does it also
compound or otherwise effect the character of impedance ??

Anybody want to clear this up for me ??

Or is my mind

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:Richard.Brekne@grieg.uib.no