1. 5GHz – WLAN Channels
EU 5GHz Channels (DFS Channels – Ch 52 ~ CH 64 & Ch 100 ~140)
5170
MHz
5330
5490
5710
Number of Channels
With DFS/ Without DFS
IEEE Channel # 36 40 44 48 52 56 60 64
100
104
108
112
116
120
124
128
132
136
140
11a
11n_HT20
19/4
11n_HT40
9/2
11ac_VHT80
4/1
Nighthawk X6: R8000
5GHz- Low Band Channel  
5GHz- High Band Channel  
To take advantage of the two 5GHz WiFi bands in Nighthawk X6 the client needs to support DFS channels.
Typically all clients support DFS channels
But not all routers support DFS, so if using a router as bridge please ensure it supports DFS-CE channels.
Netgear AC Routers that support DFS CE:
R6300v2
R7500
R7000 has passed DFS CE firmware release is planned in April; early release available now
NETGEAR Confidential - For INTERNAL Use Only