Historically stave shells have been made extra thick in order to maintain necessary strength. This caused them to have less resonance and a higher pitch. Archetype shells are only 1/4¨ thick, which is even thinner than many companies ply shells! The secret is in HD´s integrated reinforcement rings. The rings are not glued in, they are part of the actual shell. They provide the necessary strength while the thin shell wall enables the shell to resonate freely and lowers the fundamental note, thus greatly increasing the tuning range.
Vertical Wood Grain:
Vertically oriented wood grain lowers the shells fundamental note, locates the bearing edge on the end grain of the wood, which is much stronger than the face grain. It also increases the shells responsiveness and sensitivity because sound travels twice as fast with the grain than it does against the grain.