Realistically, my speaker sensitivity is between 86-87.5 dB tops. Duke tested the midbass driver personally but I lost the specs. The midbass maker specifies about 89 db but they're dreaming as is normally the case.
IIRC my room is about 3300cf, w-w carpet, bass modes are so many and so severe that a normal sub in this room is unlivable...meaning: account for bass boost. In this room the S30 had plenty of headroom, and as stated sounded more powerful than the Plinius SA-50 MkIII pure class A, not a slouch power wise, about 55 lbs.
I imagine the S30 powering Duke's 93 dB JM (its long-discontinued 11" TAD midbass certainly being one of the best extant) would make the equivalent of about 4x the power with its approximately 6dB greater sensitivity (doubling for each +3dB sensitivity), for about 120W compared to its 30W driving my speakers.
That said, Bill's room may be about identical to yours in size. IIRC, Bill, being used to the scenes described above, found the S30 lacking compared to his 200W Jolida Music Envoy monos. From his description, it was lacking more than the extra 2.5 dB, sounding threadbare in the bass when stretched. I was surprised when I heard his reaction till I listened to Ozzy with him.
At my place the S30 lacked nothing in overall performance, especially power, dynamics, headroom. My midbass are a piddling 6.5", stressing the amp far less. I'd almost positively get different speakers if I didn't/couldn't use multiple subs.
IMO the one and only person who can accurately judge pass or no pass for any specific listener/amp/speaker/room/music interface (all are indelibly interconnected, change one and the house of cards may tumble apart) is the individual listener.
Actually, even if every parameter staid the same but the listener's mood changed, you might even get a different result! Sometimes you just want to rock out an rolls the windows down, other times you want it nice and quiet with no rough edges.
