I had the same problem with my Bose headphones. Solved it by following the headphone directions to clear the bluetooth from previous connections by holding the power button for 10 sec. until it said that bluetooth connections are clear, ready to pair. U probably need to do the same if ur speaker was perviously connected to something else. After that, my headphones appeared on the Bluetooth list. If that doesn't do it, follow the steps on this link to clear and debug the Bluetooth on your laptop. I went straight to method 4 as it was fairly easy. Good luck. http://www.idownloadblog.com/2016/02/01/experiencing-bluetooth-problems-on-your- mac-try-this/
Sony Wh H900n Mac Software Reviews
Sony Wh H900n Review
Discover the WH-H900N h.ear on 2 Wireless Noise-Canceling Headphones from Sony & explore all the Headband features. Enjoy more music, more comfort, and colors that fit seamlessly into your world. The h.ear on 2 Wireless NC features High-Resolution Audio for studio-quality sound, plus better BLUETOOTH® streaming with LDAC™. Find firmware updates, drivers and software downloads for WH-H900N.