The teenage engineering rumble is a hardware expansion module for the OP-Z, featuring a built-in haptic subwoofer, which uses high-definition vibrotactile feedback and psychoacoustic technology to allow you to feel your music.
Once installed, the rumble module will sound and feel like you're holding and listening to a deep sounding subwoofer with a frequency response from 10 to 150 Hz. The unit maximizes impact, while minimizing energy consumption. Additionally, the rumble module can be used in a silent metronome mode for musicians who need a solid timing reference while playing live.