
This is really surprising! I never would have imagined! I originally intended the Nu pickup to be used as a per-string guitar pickup when I designed it. However, as time passed, it ended up being used in a variety of other applications, including electric bass guitars with 4 to 6 strings, upright basses, cellos, and more. Who would have thought it could be used for drums?
This project is the brainchild of Rodrigo Constanzo.
The OP-Sensor (Open Percussion Sensor (name likely to change!)) is currently being developed to act as an alternative interface for the SP-Tools package, a set of machine learning tools for drums and percussion, based in Max.
The Nu capsules were a fantastic discovery, being completely self-contained and battery power-able, which has made designing around them significantly easier.
The SP-Tools project that this hardware is a subset of is a set of abstractions, based round the Fluid Corpus Manipulation toolkit, that are optimized for low latency and real-time performance processes including super low latency onset detection, onset-based descriptor analysis, classification and clustering, corpus analysis and querying, neural network predictive regression, and a slew of other abstractions that are optimized for drum and percussion sounds.
The tools can be used with OP-Sensors, Sensory Percussion sensors, ordinary drum triggers, or any audio input.
Here’s an audio clip Rodrigo shared:
I’m attaching an audio comparison so you can hear the “audio” from the Sensory Percussion sensor vs my diy one based on a nu capsule. Both clips were recorded at the same exact time, and I just put them one after the other for ease of comparison. The audio itself isn’t typically heard in this context, but having (significantly) better signal-to-noise ratio, and flatter response will lead to better descriptor analysis, classification, regression, etc…
How does it work? As far as I can understand, a thin metal disk is affixed to the drum head, and the Nu capsule is positioned facing downwards towards the disk. The Nu capsule detects the vibrations produced by the drum head in the same way that it would detect vibrations from strings. Nu capsule precisely captures the drum vibrations with high resolution thanks to its flat and full frequency response.
Picture gallery below: