Hi, I’ll give you the short version, as the viol family is steeped in tradition, measurements and physics.
Basically, the sound post in a bowed instrument has a very crucial role to play, and its fitting and positioning is very important to the tone and volume of the instrument.
The bass bar is a support brace and sits under the bass side leg of the bridge.
As with all stringed instruments plucked or bowed, the strings create a minute rocking action in the bridge that in turn moves the top, which in turn moves air in the box etc, etc. The rocking direction on our guitars is usually front to backwards, but the string vibrations in the viol family are usually side to side, due the pulling/pushing action of the bow.
So, to allow the bridge to “rock” more efficiently sideways a post is used under/near the treble foot of the bridge so that the bridge may pivot on the less flexible bass bar.
This post of course couples the top to the back and brings the back into the sound producing arena. The top and back are usually “tuned” to work with each other, as they are in good full-size guitars.
Will it work/be beneficial in a small wine box? I have not been there, but think not, but if you try it let us know.
Taff ….Oh that was the short version Ha ha.
Thanks for the detailed reply. I'll have to think on this. I don't expect the instrument to be bowed. I'm not adverse to doing what is needed but I also don't like the idea of doing what is not needed. Agian, thanks for the reply; very informative.
Hi JD thanks your welcome.
Just thought I would mention that an acoustic bass guitar normally has guitar style bracing and no soundpost.
Thanks Taffy, I appreciate your input. I think I'm going skip the sound post.