(Sound production in a Banjo
There was a time in my life that I decided to what I could to improve musical instruments. I played the banjo, so one of the first instruments I chose to work on was what I played; a 1957 Gibson arch-top Mastertone. So, I built a replacement rim of: Koa, Mahogany, Black Walnut, Black Walnut, Mahogany Koa. The results were not very desirable It was very sweet tone but not a sharp punch. I abandon this rim going back to original. Several years later I made a Rim of Rosewood. It was much better than Maple. I also got to thinking about older banjoes their rims were much thinner some only ¼ thick. I dismounted the neck and took out rim crossing hardware but left everything else a Pot as Stewart MacDonald call them. With a sharp hunting knife I started scraping on the rim thinning it. I left the tone ring contact intact. I would scrape a little then tap the pot with butt of the knife. I continued doing this until overtone converged. I scraped about ¼ from the ¾ thick banjo rim. Thinning the rim greatly improving the sound of the banjo.
A friend brought me inexpensive banjo and asked me if there was anything I could do to improve the sound. The rim was solid cast aluminum I found by placing two layers of wood in side the aluminum it dampened the un wanted over tones.
John Alden Robinson
17415 N. 75th Ave
Glendale, AZ 85308