Denmark’s DALI has added a second center-channel speaker to its Oberon series of home theater speakers and announced that it is now shipping the high-end IO-12 wireless headphones it previewed in October. Designed for large rooms, the new Grand Vokal center speaker ($1,000) is a higher power handling version of the existing Vokal that mates the same 1.1-inch soft-dome tweeter with a pair of 7-inch wood-fiber-cone woofers (instead of 5.25-inchers) in a ported cabinet 17 inches wide, 6.3