Ratio for bass machine heads is a tuning system that increases the predictability and efficiency by taking the guess work out of tuning. On conventional bass machine heads, each strings' machine head has the same gear ration; however, each string has a unique string diameter, causing each of the strings to react differently to the turn of the machine head. With Ration for bass, each string has its own specific gear ratio, so that every string reacts to the same turn of a machine head.
Since each string’s core diameter is different, a specific gear ratio for each string was researched and developed to ensure that each string reacted the same way to the turn of a machine head. The result for a 4 string bass is one full rotation of any key results in a one full tone pitch change (give or take). From Low E to G, the gear ratio's are 36:1, 30:1, 20:1, and 18:1. For a 5 string bass, one full rotation of any key results in a one full tone pitch change (give or take). From Low B to G, the gear ratio's are 48:1, 36:1, 30:1, 20:1, and 18:1.
