The predominant factor in our sound system is the room.  The shape of the room, it's size — the ratio of the sides, the construction materials, the openings to the outside and inside.

Then we have the contents of the room, the selection of the speakers and their placement.  The furniture, the people and their placement are next in line to address.  It is a wonder that we can get our systems to sound right!  What is right?

I have been on the inside and the outside of this industry for a long time.  I have observed first hand what a re-designed performance hall sounds like before and after reconstruction. The hall now has many many more seats with improved audio quality.

I have been fortunate to listen in purpose-built rooms from around a million dollars to many average homes of different shapes and sizes.  Some sounded great some did not.  I hated the sound of the speakers in a couple of the fancy rooms and loved the sound in much simpler ones.  

I do not want to lock my head in a vice in a chair nailed to the floor of the room.  I want to be able to live with my system.  So does my family.  

There are hundreds of webpages, papers on the internet.  I have found one here on Audiophile Style that is a fascinating summary of the problems we face.  Thanks to @mitchco for the great review of the KII Three speakers and the overview of the effects of the room.