This rig.
Going from 2 10s on ~300w to 4 15s on a 7.5k was a change to say the least
I had no idea what to expect. I figured it would just be like turning up the radio a bit more. NOPE. I had zero frame of reference for just what "loud" was. It threw me for a loop - feeling it in my chest, whole interior shaking, having it grab my throat, and the physical sensation of my eardrums flexing. 10/10 was a great time