Many of these threads can contain posts that ignore the OP’s question. Look at his request again. He clearly states his mission, his concerns and the equipment he has.
The major variables in this game are the listening room accoustics, desired audio levels, and the recordings played. And then there is the equipment. Like countless other audiophiles it sounds like the OP purchased quality efficient speakers and other components. Playing digital music can bring a of lot desired qualities to the table: big sound stage, clarity, speed, and detail. Digitally sourced audio can also be like a digital photograph that has too much sharpening added: at first glance at a distance it looks great, but a closer more focused look reveals an unnatural false graininess.
Some systems (even expensive ones) can sound wonderful at first, but longer listening periods bring fatigue and a desire to turn the volume down. The common quest is system matching to fix this. Focussing only on sine wave measurements without actual listening just makes this harder...
The major variables in this game are the listening room accoustics, desired audio levels, and the recordings played. And then there is the equipment. Like countless other audiophiles it sounds like the OP purchased quality efficient speakers and other components. Playing digital music can bring a of lot desired qualities to the table: big sound stage, clarity, speed, and detail. Digitally sourced audio can also be like a digital photograph that has too much sharpening added: at first glance at a distance it looks great, but a closer more focused look reveals an unnatural false graininess.
Some systems (even expensive ones) can sound wonderful at first, but longer listening periods bring fatigue and a desire to turn the volume down. The common quest is system matching to fix this. Focussing only on sine wave measurements without actual listening just makes this harder...