There’s plenty of portable Bluetooth speakers out there, just like there’s plenty of, uh, screws. But the Harman Kardon Onyx ($500) is aiming to be more than an also-ran; it’s looking to seize the throne. The Onyx is boasting of best-in-class sound anytime and anywhere you need it with its 4-speaker, advanced acoustic platform, and dual passive radiators. Connect via NFC, Airplay, DLNA for Android, or the auxiliary input and you can make a strong case for (audio) black power.