I had the same problem with the rear ports on my B and W CM8 S2’s, but I trialled the included foam port blanks, and used in their full two part config. They worked wonders, plenty of bass out of the front and boominess eradicated. Might be worth a try? The B and W’s ideally need a space of 500mm all round them, unfortunately they have nothing approaching that (100mm behind!!) but the foam did its job and they sound superb (with a Nova).
A very special visitor. Having watched your video about Bob and Art Dudleys Altecs again just a few weeks ago, reminded me just how much I miss Art. Nice to see Bob back again, he looks quite comfortable listening to your system.
The office / daughters bedroom system, listening in here tonight seeing as the kids have taken over the living room temporarily, normal service resumed in an hour or so.