I have that exact setup in my living room. Listening area is about 17’ x 13.5’, speakers along the long wall, 18 - 24 inches from the wall, into the room.
For reference, I live in a coop building outside of NYC so…in the evenings I don’t get past maybe 78db peaks. Was listening to Muddy Waters (sorry, forgot which, just shut my stereo off for the night) and I happened to check how loud the peaks were. Just playing around. When the volume on the INT 25 was at 42 or 43 I was getting peaks of 77 and 78 db. I think at 48 or 49 I’d be getting a knock on the door. The volume on the INT25 goes up to 63. I hear no degradation at higher volumes.
Hope that helps a bit. Btw it’s the most realistic reproduction of my kind of music (jazz, blues, piano, acoustic guitar, etc) that I can remember in my home since I had Quad ESL63’s paired with a big CJ 140 tube amp years ago).