Are you operating in the correct SPL window for high-fidelity listening?

I feel like SPL is both mood- and recording-dependent. 

Sometimes I’ll listen to 100 db sludge metal while performing certain tasks because it helps me focus. 

Other times, I am content listening to sixties big band at volumes that don’t intrude on quiet conversation.

A good system should accommodate both without significant loss of sound quality or resolution. I find that the upper limit beyond which listening becomes uncomfortable is determined more by the room than by the system, in my case that is. 

Preamplification / attenuation is a topic unto itself that has not been satisfactory explained in this thread so far, and though not the main topic it is inextricably linked. Suffice it to say that a very good volume control can make a significant improvement in sound quality, while a mediocre one (which is to say the vast majority) has the ability to ruin your low-SPL listening experience.

This thread reminds me of conversations I have had with employees. I would give them an assignment. They would return and tell me it could not be done. I told them I was not interested in the ten ways it could not be done but only in the one way it could be done. 90% of the time they then returned with a solution. 

Garbage in, garbage out.

If you want meaningful data, stipulate a method for making the measurement and with what device. For example:

from listening position

meter at head height aimed at a point mid way between stereo speakers

state nature of the music

what meter

A or C weighted?

room size