At first glance, it might look like any other portable speaker. Yet the OB-4 "Magic Radio" from Teenage Engineering is far more than it appears. Whether playing via the 3.5mm line input, Bluetooth, or FM radio, it stores a rolling two-hour recording of everything you play and gives you a platter-like wheel to rewind and remix as you wish. Sound comes from two 4-inch bass drivers and two neodymium tweeters, powered by class D amps outputting 38 watts per channel. It also has a Disk option, a programmatic offering that plays one of three modes and can be updated in the future. The rechargeable battery can last for eight hours of high-volume Bluetooth playback or up to 72 hours of normal volume FM, and the integrated handle folds down to become a stand when needed.