Be wary in your thinking.
2.4 GHz is the "centre" frequency of the radio band used by WiFi, not its "speed"; and that radio band is shared with many legally and officially-unlicensed items, such as microwave cookers, baby monitors etc.
Similar for the 5 GHz Wi Fi, although less sharing with other devices.
Technically the 5 GHZ has less penetrating ability etc through walls etc, ie it is absorbed and turned in to heat - miniscule etc but still very much attenuated as a radio signal.
In my own case, the 5 GHz circuit is typically 10 dB worse than the 2.4 GHz, around the house and garden etc. Measured at about 20 points.
Edited by eckiedoo (Thu 11-May-17 07:45:22)