You likely would be better off using 2.4G for the Echo, because that freq has longer range and depending upon where your router and Echo are relatively located, you might get a stronger signal from 2.4. I do, so my Echo is on 2.4G with other "slower" devices. Besides, the Echo does not require higher bandwidth, since it only streams music. Video streaming of HD, on the other hand, does require higher bandwidth, and is why 5G was created. Now that you can differentiate between the two, use any wireless video streaming to devices using the 5G. I do. In fact, I don't even allow my phone and tablet to connect to my 2.4G; only to 5G.