The bearing edge angle on the bass drum differs from the angle on tom and snare shells. A 45-degree /R1.5 edge is used on the snare and toms to achieve a balanced tone, while the 30-degree/R1.5 edge on the bass drum creates a low-end tone, for a deeper, more powerful sound.
Through an exhaustive series of prototypes, Yamaha has discovered the optimal number and vent hole position depending on the air capacity of each shell. Particularly, vent holes contribute to the enhancement of tone colors in midrange to low-frequency sounds, as well as the control of sustain.