I ordered a tone ring from Stewart-MacDonald. This had no holes in it, but it sounded a little better than the original Gibson ring. I began to analyze the situation, and I realized what part of the problem was. The chamber inside the tone ring did not communicate with the outside world. It was a dead air space.
Dead air is an insulator.
It is what makes acoustical tile work. If you seal off the sound hole of your guitar, it muffles the sound. The sound was there, but it couldn't get out. Then I remembered the letter from Davis Kennedy. I took the banjo to a friend of mine who turned wooden columns for a living.