No, we’re not talking about battleground tactics or that nifty option in the dash of your new Lexus. Positional sensing is a term coined by electronic percussion manufacturers to describe the ability of a sound module to register and respond to hits at different locations of a drum pad or head. One example might be a tom that sounds full when struck dead center but has progressively more ring and slightly higher pitch as you strike closer and closer to the edge. Sometimes positional sensing is used to select an entirely different sample based on location of the hit.
Positional sensing is not the same thing as multiple zones, which describe a pad with discrete sensors located at different points. The most common example is a dual-zone pad with one trigger at dead center and a second one under the rim. Hitting one zone or another physically activates a specific trigger or switch. However, positional sensing requires at least two sensors to operate. It reads the impact registered by both sensors and expresses those as a ratio (remember, a sensor is always operating even though it only generates a sound when a hit reaches a predefined threshold).
Roland TD-8, TD-10, TD-12 and TD-20 modules support positional sensing on several presets. Roland uses MIDI Continuous Controller 16 for this function, which means that the range of variation can be from 0 to 127. Clavia ddrum3 and ddrum4 modules also support positional sensing. These units read trigger input as analog signals first, which theoretically means their range of response is virtually unlimited. Yamaha DTXTREME modules can take advantage of the RHP120SD pad’s three sensors to add sensitivity to some presets.