Sony XB40 Extra Bass Portable Bluetooth Speaker. IPX5 rated, this Extra Bass speaker is suitable for playing music at the poolside, beach, and more. The Sony XB40 Extra Bass Portable Bluetooth Speaker is equipped with dual passive radiators and a 61mm full range speaker system to deliver clear audio with improved low tones. Just press the EXTRA BASS button to further boost bass output. Light and compact, the XB40 speaker can be easily stored inside your bag and brought along to beach parties, fishing expeditions, and barbecues.