I heard the PS Audio IRSs on a visit to Boulder about 5 years ago. They were as expected, an immense soundstage, great dynamics, and huge presence. Line arrays in general are not my cup of tea, but I still enjoyed these historic and quite grand speakers.
I brought a 30-something year old, non-audiophile colleague with me to the demo. He asked one of the best questions I’ve ever heard in a demo, “how does it know where to put the voices and instruments?” I found this to be a fascinating question and one that ignited a good deal of explanation (to the best of my ability!)
Paul McGowan, Arnie Nudell, and the mighty Infiniity Reference Standards are integral parts of our audiophile history.