With a converted basement room 13' x 20', speaker placement for me worked best along the short wall. Speakers are about 1 1/2' from each wall and 8 1/2' apart. Listening area about 9' from speakers. This gave more area behind to deal with reflections, etc., and gave a better soundstage and "open" sound, especially with a small number of instruments/singers on quality recordings. In other words, it made it sound like I was listening in a larger room.
Others have made good room treatment suggestions. I went the DIY route with 2' x 2' and 2' x 4' panels with Knauf insulation from GIK, (much easier to work with than Owen Corning stuff). Besides the typical bass traps placed at 45 degree angles in the corners and the first and second reflection points, I was surprized how panels placed on the ceiling also helped with controlling higher frequency congestion, (ceilings are 7 1/2').
Room EQ Wizard as a starting point, then moved the panels to preference. Good luck finding what works best for you creating your new listening room.
Others have made good room treatment suggestions. I went the DIY route with 2' x 2' and 2' x 4' panels with Knauf insulation from GIK, (much easier to work with than Owen Corning stuff). Besides the typical bass traps placed at 45 degree angles in the corners and the first and second reflection points, I was surprized how panels placed on the ceiling also helped with controlling higher frequency congestion, (ceilings are 7 1/2').
Room EQ Wizard as a starting point, then moved the panels to preference. Good luck finding what works best for you creating your new listening room.