The Arctis 9X is a Bluetooth-enabled headset!
Even better, the 9X uses a dual-wireless system. What does this mean?
It means that the headset connects to the Xbox via a wireless connection, & you can connect to a mobile device via Bluetooth, at the same time.
Even farther: Dual Wireless means the headset is able to stream two wireless audio sources at the same time: one audio source from the 2.4GHz transmitter, and one audio source from a Bluetooth device. This allows you to listen to two different things simultaneously, like a podcast on your phone while you are gaming. There are hundreds of different possibilities and compatibilities thanks to the versatility of dual wireless.
How does that work? (ﾉ◕ヮ◕)ﾉ*:・ﾟ✧ mAgIc *~