I keep all of my snakes at 84° average, no cool side no hotspot, but that is also in a thermostatically controlled heated room. Colder species snakes on the floor level, and ones that require higher temps on top. In a singular enclosure your temps may not be high enough ambient to allow proper digestion, and snakes that know it's too cold to digest won't eat. If your ambients are in the 70's, and your warm side is only mid-upper 80's, it may be too cold for them.
I like my Dubstep to go Wop Wop Wop Wop