The knobs and other parts on the Stanmore IV and Acton IV speakers are replaceable. | Image: Marshall Marshall announced new versions of its Acton and Stanmore Bluetooth speakers today with upgraded tweeters, bass ports, and internal designs that improve their ability to fill a room with sou nd. Both the Acton IV and Stanmore IV replace their four-year-old predecessors with a new focus on repairability. Parts including knobs, feet, and the speakers' front grills bearing the iconic Marshall logo are replaceable should they get damaged. The smaller Acton IV, featuring a 4-inch woofer and a pair of 0.75-inch tweeters, is available starting today for $299.99 through Marshall's online store. The Stanmore IV, which has a similar driver setup but w … Read the full story at The Verge. ...read more read less