Help with Responsiveness

[Andreas Preuss]

2 hours ago, David Stiles said:

Actually, this violin has string angle of 160 deg, a little flatter than target. Fingerboard projection dropped nearly 1.5mm under string load. 

Sorry, I would say a lot flatter. 
 

And if the projection dropped 1.5mm I would say it needs to be reset. If the projection gets too low this definitely affects the sound focus. Again it depends in my view a lot on how light and flexible the top is made.

2 hours ago, David Stiles said:

In guitar world there is a theory that stiff linings reflect vibrations back into the plate and make it work like a larger plate and increasing radiation.  What have you found in violins? 

What I have found on violins is mostly documented in the new concept violin thread. The lesson I am taking from there is that you can build a somewhat too thin top and make it work properly mostly with adjustments on the ribs.

1. The width and strength of the linings. I think soon I will switch to make linings always from bamboo, because it is the better material. 
2. The surface long arch of the ribs, which serves to increase the long arch of the top.
3. To prevent the dropping of the neck you need to double the linings of the upper bouts on the top side.

whatever is the cause of these building features, if diligently used, it works well, and better than changing bass bars, thinking of miraculous sound post positions and other adjustments. The latter ones are for me still important micro adjustments, but before that you need to get the macro adjustments right.

My unscientific reasoning is that a violin is a sort of clamped by the string tension on the vertical axis. In this direction it is a ‘system without freedom’

On the horizontal axis there is absolutely nothing which can control forces and resulting movements. It is a ‘free system’. And if it gets too loose it doesn’t work properly.