Don't overlook the importance of getting your ears to the right height, especially in the nearfield. This will depend on your particular speakers, of course, but a general rule is to get your ear between the midrange and tweeter. I just raised my chair (by putting clay bricks under the feet) and was very happy with the improvement in sound. It's actually more comfortable, too. This is almost as significant as speaker placement.
Your Listening chair
How elaborate is your chair? I use a beach chair and use two throw pillows to reach the tweeter height.Very transparent, acoustically. Only problem is the back support just ends up little below my neck level.And does not provide head rest-which is painful for longer sessions. My question: How important not to have a head rest on your chair? I have experimented with a head rest and sound becomes somewhat non-transparent loosing its ambience. Without the head rest sound is more open and natural.