Agreed on the points Erik listed - but in additon to those treatments
- I have found that treatments at ceiling hight at the wall behind the listener to be beneficial
- I have used a "vinyl curtain" mounted at ceiling height, dropping down around 18 inches
- You can buy clear vinyl around 1mm thick from the web for a less noticeable application
- I did try different lengths, but 18" was th optimum
- my room was 12 x 15 and 8ft high, with a window behind the listening position and a double opening in the center of the left hand wall
I noticed improved clarity and details once the drape was employed
I also tried this at a friends apartment and it worked very well
- the ceiling was concrete and 12 ft high, the floors were hardwood and it was open plan - so the reflections were coming form everywhere
- the vinyl drape was employed in a couple of places at the wall/ceiling boundary and it worked extremely well
Regards - Steve