What is the most overlooked consideration?

Quality stands for equipment and speakers.  What components and speakers are placed on dramatically influences everything from noise floor to sound stage and dynamics.  Few years ago I placed a very respectable system initially on an IKEA bench, (yes I know better), then finally placed everything on a proper Quadrasprie SVT stand, beyond shocking.  I knew better, but wow!  Everything radically fell into place.

Many items outside components and speakers are overlooked, I find that particular item the most frequently dismissed, misunderstood and oft poorly executed.

I have to wonder why so many contributors here are assuming that something as basic as room acoustics is being overlooked. Are they merely misunderstanding the question and confusing "overlooked" with "most important", two completely different things? I have no way of knowing but I really doubt that many people on this forum have overlooked the importance of their room as it applies to sound quality. Or maybe the assumption is that listeners outside of this forum are overlooking their rooms?

Where you position your speakers and good cables,but you don't need cables that cost hundreds of dollars....

Many people building a system often underappreciate the Preamplifier. Be very careful and audition in your system without compromise.

imho, people underestimate importance of clean power.  I put in a new dedicated 20amp service for my "rig".  I also spent 500 on a high end Furutech plug in the wall.  These two actions made a Huge difference in sound.