The Harman Kardon Onyx Studio 4 is a Bluetooth speaker with a powerful sound and 8-hour battery life. The speaker produces 60 watts when it's plugged into a socket and 30 watts when it's playing music via the battery. In both cases, you can easily fill an entire living room with music. You can connect 2 devices to the speaker simultaneously, so you can take turns playing your favorite songs. Call hands-free via the speaker with the integrated microphone. You can always be heard thanks to the echo and noise suppression. For an even more powerful sound, you can connect multiple ¿ up to 100 ¿ Onyx Studio 4 speakers together.