The JoyStyx Quartet is a series of four embedded acoustic instruments. Each of these instruments is a five-voice granular synthesizer which processes a different sound source to give each a unique timbre and range. The performer interacts with these voices individually with five joysticks positioned to lay under the performer's fingertips. The JoyStyx uses a custom-designed printed circuit board. This board provides the joystick layout and connects them to an Arduino Micro, which serializes the ten analog X/Y position values and the five digital button presses. This data controls the granular and spatial parameters of a Pure Data patch running on a Raspberry Pi 2. The nature of the JoyStyx construction causes the frequency response to be coloured by the materials and their geometry, leading to a unique timbre. This endows the instrument with a more ``analog'' or ``natural'' sound, despite relying on computer-based algorithms. In concert, the quartet performance with the JoyStyx may potentially be the first performance ever with a quartet of Embedded Acoustic Instruments.