pvc rings and strings

From: daniel G. Soergel (dsoergel@juno.com)
Date: Tue Mar 12 2002 - 21:02:03 PST


-I'll stick with it and look for ways to improve them

I've discovered an interesting way to greatly improve the sound of pvc
shakuhachi. The naturally occurring nodes in bamboo seem to create a
denser, thicker and more rigid tube in certain areas, leaving other areas
along the length resonant. These variations effect the sound quality of
each particular flute, quite apart from the shape of the bore. Where the
wave form of a note corresponds to a node, the note is reinforced...
there is more air pressure at that point and the tube is stronger there.
But where the node is merely close to where it should be to strengthen a
note, a certain character is added to the sound. In bamboo you cannot
experiment with node placement and density, but in pvc...

Since polyvinyl chloride is extruded there is some molecular orientation
along the bore axis, but it seems pvc will never come close to
approximating the linear grain of bamboo. But nodes can be easily made by
simply cutting rings out of 1" tube and slipping them over 3/4" tube.
Starting with a reinforcing ring at both ends, an improvement is clearly
apparent. Once the holes are drilled, the fun comes from sliding more
rings into places that make the flute come alive with character. I know
this will sound controversial, but I discovered that after carefully
locating all the holes, moving rings along the length effected pitch of
individual notes as well. Try it.

Adding a joint does not seem to effect sound very much, and it makes the
flute even more practical. The finishing touch is adding the linear
fibers that pvc lacks. Wrap monofilament (fishing line) around the nodes
in tight bundles. (Strings and cords don't sound as nice- no pun
intended). Try varying the spacing of the wrap, crisscrossing along the
entire length of the flute. In mass production this is called filament
winding.(used in bomb casings!) It adds strengths selectively like
carbon fiber hand lay ups (fiberglass&resin). The improvement in sound
from winding is substantial.

All said and done, these ugly ducklings sound wonderful. I play them
hours at a time, since they don't sound dull and dead like wood or naked
pvc. I measured the 2.0 and put the plans on my site
HTTP:www.konkle.com/shakuhachi under the "about the shakuhachi" section.
Actually, a grey flute with white nodes looks real nice.

Daniel Soergel

________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/web/.



This archive was generated by hypermail 2b29 : Mon Feb 03 2003 - 09:09:51 PST