Sorry for commenting so long after the previous posts but want to add this:
In my (still budding) experience as a mobile DJ the nature of the room influences whether I use either those big QSC subs or my preferred choice, which is the compact but still very effective K-Sub.
If the room is not huge, a pair of K-Subs placed next to each other under my DJ table (hidden from view) rocks. By putting them next to each other you effectively increase their db capacity.
I learned this trick from a YouTube video made by a very experienced, high-end weddings DJ. I tried it and can attest it works.
Moreover, I must admit that being of DJ Vintage’s age group