The first sound converter system to be created especially for the Cajon is based on a freely oscillating and mountable dynamic sound converter unit for the sound output aperture at the back of a Cajon. The low-resistance, passive system is phase-defined and can be connected to a low-frequency amplifier using a XLR plug or through a conventional mixer. The frequency spectrum includes not only the Cajon"s important bass range but also the mid and treble range. The entirely flexible system is easy and convenient to assemble thanks to the mounting blocks. The plug and play system is ready to use in a matter of seconds, eliminating any problems with positioning microphones.