Sony is increasing their EXTRA BASS (XB) line of headphones today with the announcement of four new models. The first to be unveiled is Sony's MDR-XB510AS EXTRA BASS in-ear headphone. This is a sports headphone with bassheads in mind. Featuring an IPX5/7 water-proof design, this bass-boosted in-ear is targeting active users who like to spend their time relaxing by the pool or running in the rain. Accessories include an arc supporter, cord adjuster, clip and mesh carrying pouch. (Sony MDR-XB510AS) Next up is the newest wired addition to the XB family, the MDR-XB550AP EXTRA BASS wired on-ear headphone. The premium metal headband, custom cups and 30mm drivers are all designed to deliver deep, punchy bass alongside what Sony call a balanced sound. There's an in-line remote for phone calls and an Android app lets the user customize the remote. The MDR-XB550AP EXTRA BASS will be available in red, green, blue, black and white. (Sony MDR-XB550AP) On the wireless side Sony is releasing two new XB models in form of the MDR-XB950N1 EXTRA BASS and MDR-XB950B1 EXTRA BASS. Both headphones support a wireless Bluetooth connection with aptX and AAC alongside NFC pairing. There's a smartphone app available that allows the listener to emulate different environments like a club, arena, concert hall and more. It also features EQ settings so the user can personalize their sound. The N1 has a few extra tricks compared to the B1, tricks like active noise cancellation (ANC) and 22 hours of wireless listening compared to the more modest 18 hours of the B1 model. The N1's ANC can be enabled and disabled in Sony's app. (Sony MDR-XB950N1) No pricing has been announced for these headphones but we expect to see them on shelves sometime in the spring. For more information be sure to check out Sony's blog here.