When bass player Yerko Sepulveda had trouble hearing the sound of his instrument in a particularly busy mix, he opted to build a device that would allow him to feel the thunder. The resulting portable rumble box – named BackBeat – is clipped to a player's strap to deliver low end you can feel.

Sepulveda's box of tricks is not the first portable subwoofer we've seen. The SubPac M2 and Baserock do the same kind of thing as the BackBeat, but the latter's application as a musician's aid is what's interesting here – turning the sound of a slapped, plucked or tapped bass string into a vibration. Its 2-inch transducer is said to deliver a force of 10 N.

The 72 x 170 x 24 mm (2.8 x 6.7 x 0.9 inch) device is fitted to a bass guitar strap, with the cable from the instrument plugging into a 0.25-inch TRS jack for solo low end thump. The signal can also pass through the BackBeat on its way to an amplifier or wireless transmitter via an output jack on the wearable subwoofer, and there's an output buffer to maintain a steady signal.

For a little extra dimension, gigging bassists can plug in IEMs to monitor onstage performance. The BackBeat will vibrate the instrument output below 200 Hz, while the headphone output will deliver stereo 20 Hz - 20 kHz sound to the IEMs.

Users can control the intensity of the vibration using a knob to the top, while another potentiometer determines headphone volume. An 11.1 V Li-ion battery keeps things portable, though a DC input allows for mains connection (and doubles as a charging port for the internal battery).

The BackBeat project has already rumbled through its Kickstarter target, with a little less than a month remaining on the campaign clock. Pledges start at US$299 for a BackBeat, a soft case, an instrument cable, a charging adapter and a cable strap organizer. If all goes to plan, shipping to backers is estimated to start in September. The pitch video below has more on the project.

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