What you are seeing are 4 Everests arranged in a WTMW array. The customer wanted the tall sound stage he was used to with his previous (vastly more expensive ) speakers, but wanted the JBL clarity and dynamics.
The array is actively multiamped; those are Bryston 28's in the background, and they are all controlled by DSP based crossover/eq/time-delay. Final tuning is done by ear on a variety of acoustic recordings, including personal recordings of the customer's piano.