Dynaudio C1 and Pass amp

Anyone has experience with this combo? Particular Pass XA30.5.
I had no problem with volume on my aleph 3 + Confidence 3 combo -- just a sharp drop off in bass response below 100hz. This was a problem in 3 different listening rooms of different dimensions from small to large in three different houses. The problem may have been the speakers, may have been some bass-dampening phenomenon common to each room -- or it may have been an under-powered amp.

The sound I did get was astonishingly beautiful, though.
Hi Rr999,
Does Aleph 3 go into A/B mode after it goes out of class A? My understanding is Pass only starts doing that with their XA.5 series. This should help in dynamic swings and maybe able to explain your 100Hz roll-off? I could be wrong.

Hi. There is some debate about the pass xa30.5 driving speakers to a high levels. I have used this amp since its launch and prior to this a X350 power amp which claims some 350 watts output power. What i can say is that both provided lots of power at usable levels. Certainly more than enough volume. Im talking about volumes that are comfortable but loud, not ear damaging loudness thats no use in normal domestic settings. However I do recall the 350 having a touch more slam but not quite the extreme clarity of the newer but weaker model.
C1 Sigs have arrived. XA30.5 has absolutely no problem driving the Sigs in my 18x25 room. My normal listening level is 75-80db average SPL with peak of 85-90db at the sweet spot (I listen with lower level at night). Meter doesn't move from 11:30 position even for bass heavy materials. I tried to push a bit harder and it seems I have a good 8-9 db headroom above my normal listening level before the Pass needle starts to move to the right side (leaving class A). And that is at very loud level and I'd never listen at this level for extended period of time.

I set the speakers on the short wall with 8 feet between them. 2 feet from the back wall and sweet spot is 9 feet away from both speakers. The music has great slam and dynamic swings are handled pretty well.