I think it’s a combination of room and speakers. There’s a point in sound pressure/volume where the room begins to be heard and often a small range above this that is useful. Below this range, soundstage is small, and above it, standing waves and other anomalies begin to become apparent.
Natural sweet spot in your system.
Something that has haunted most of my systems is finding the sweet spot as it relates to volume. Every one of the systems I have put together the past years seems to have a volume where everything works. I go outside of that on the low or high side and things fall apart. What is the most likely cause? The room, the amplifier or the speakers. How do I increase or lower the volume and keep the same balance in the frequency spectrum.