An observation . . .

I have not been involved in PA systems for at least 20 years. The thinking back then was to take the bass out of the monitors. The bass player has a Marshall 4 x15 2 feet away so fold-back was focussed on the upper frequency ranges - vocalists need to hear what they are singing.

So, I'm watching a Trevor Noah video on Youtube and I'm wondering why he has at least six subs on fold-back?