Looking through the bookmarks on my browser, I spotted this site, which looks in detail at many aspects of banjo setup. The site owner, Bill Palmer, analyses in detail factors which alter the sound produced by the banjo and explains his findings in a sensible and understandable fashion.
Here ia a Blue Clicky which will take you to the site www.banjowizard.com
Happy tinkering
Quack!
GtD.