The most important factor in soundstage imaging

Everybody wants a system that images well. There are  many discussions here positing equipment changes that will improve imaging. Some people think the magic wand is cables, others are sure it’s the preamp, and the ones that don’t think it’s preamps, think it’s amplifiers. And, of course, speakers are (correctly) mentioned. 

However, the single most important factor in audio stereo imaging, is increasing direct radiation and decreasing reflected radiation, by moving the speakers away from the back wall, and away from the side walls.