Back in the late '70s the guy who did most of the arena gigs in Honolulu built a similar system comprised of 2-10s, 4-5 1/4s, a couple of slots and a couple of ring radiators. This sat on top of a W bin with a 15. All JBL drivers of the era. Amp rack was maybe 12U high with Yamaha amps instead of the Phase Linear he used with the older all horn system. The first time I heard it he had two stacks per side in the HIC arena with George Benson. It was the best sounding concert I'd heard to date, including folks who brought in their own touring systems. Warm and natural sounding. Didn't have the efficiency of horn loading but seemed to make up for it with the 5 way multi-amping. He built a couple more so he could have three stacks per side for louder rock shows. He would also load a bunch of empty bins and some horns into a tray that flew over the stage so it looked more rock and roll. But the 5 way stacks were carrying all the load to the front.
He had also built the system our Waikiki cabaret band used including the 250lb prototype concrete copies of JBL radial horns. He made the ones he used for the arena shows thinner and lighter but we left our system in the same club for 3 years so moving them wasn't as much an issue. Until the resort chain moved us to a bigger show room and we had to move them every night.
In any event we took a week off to play on Maui once and with no arena gig booked, he told us to leave our rig in the club and he would bring something. Given that the place on Maui was paying freight (along with rooms and meals) to get a top Waikiki band for the week. That ended up being a pair of his 5 way stacks which we set up in a large ballroom. (He also tried out some wedges Ike and Tina had sent over for a show on us) These days, most folks would consider such a rig barely adequate for a large ballroom. But in 1978 it was seriously loud.