I’ll keep it short and simple. I have a dual band router.
I want to know if having both the bands on reduces the network speed? As in if I switch the 5GHz network off... will I get a better speed on the 2.4GHz network?
Each one of those is a separate transmission medium, with separate transceivers. Thus the bandwidth values for them aren't summed up together. If you turn off either one you'll have less total bandwidth