You can connect two WONDERBOOM 2 together for bigger sound. PRESS AND HOLD the center button on both speakers at the same time until you hear the pairing tone. Once pairing succeeds, you will hear a confirmation tone and music playing on both speakers! PRESS AND HOLD the center button on both speakers again to toggle between mono mode and stereo mode. If you hear this confirmation tone, it means that you are in double-the-sound / party louder mode. If you hear this confirmation tone, it means that you are in true wireless stereo mode.