One month later, some reactions. The image has stabilized and homogenized. And a bit deeper. I don’t think the bass register I was worried about will deepen any further.
On some recordings that I already knew, the extreme low register that I was getting with the 3.5 is absent (or weak, or dry) with the 20.7
What is very strange, on the other hand, is that I discovered extreme bass on recordings where I had never heard it. Or that I had never heard so loud and well defined *
It’s as if the boundaries have been redefined, sometimes in favor of the 20.7 and sometimes not.
But overall, the low register is sovereign, perfectly articulated, and much better than 3.5
*for instance, the 32’ in San Simpliciano church, or :