The Tabolin was strung up and played with different configurations of weights on the velum panels.
Thanks to my friends Gabriel Wheaton and Joe Peterson, who helped me sound test the Tabolin
Results
With no weights
The Tabolin is responsive, balanced and quite loud. Overall it has a dark, viola like tone. I find that it has less resistance under the bow than my regular instruments, but the sound doesn’t “bottom out” with heavy bowing.
As weights are added
There are infinite possible weighting combinations and patterns for weighting the velum panels, but in general, up to a certain point, the tone becomes richer and thicker with a more treble edge as weights are added. After that point additional weights tend to make the sound more muted and tinny.
Sound can be affected by the amount of weight added to any one panel and also by the location of the weight on the panel
The tuned panels did not give noticeably more sustain to the unbowed notes, and the hoped for mimicking of the effect of the sympathetic strings on viola d’amore or Hardanger fiddle, was not apparent.
Conclusions
The Tabolin, with its tunable regions of the body, is unique amongst violins in that it can be quickly, easily and reversibly adjusted for tone. This should be of interest to players who would like to control the sound of their instruments, without the help of a violinmaker. It could also provide a platform for some avenues of violin acoustics research.
The durability of the instrument is yet to be proven, but so far it is surprisingly robust.
Update 2022
The instrument is very susceptible to changes in humidity. The same hydrophilic qualities that allowed the velum to be shrunk tight onto the panels are its downfall in humid weather. The panels get limp and the tone goes dead