Acoustic panels - how high?

oh, and another thing. not all panels are effective to the same degree and some panels do more harm than good. I wont mention any names but one of those that are ineffective is SONEX. it all kind of depends on what happens to the wave as it passes through the panel material twice.

It is possible since there was no difference in sound that the room is fine without them.
Another + for Elwood though. I used to have a few roomtunes etc..until I rebuilt the room with Crown moulding and added art to the walls.

Regardless of a speaker system's dispersion pattern, sound waves travel in a straight line and their angle of reflection will equal their angle of incidence. Thus, an easy way to find the first reflection point, of the waves that will actually reach your ears, is via the method mentioned by Elwood. (http://hyperphysics.phy-astr.gsu.edu/hbase/sound/reflec.html) Yes- a panel that will disperse or absorb those reflections must be chosen.

Further info, here: (http://realtraps.com/rfz.htm) & (http://www.gikacoustics.com/video-early-first-reflection-points/)

Thanks, good info. I have treated first and second reflection points on side walls and improved things quite a bit. Think I will now experiment with a panel on my ceiling. No mention anywhere about treating the front wall either directly between or behind the speakers. Any thoughts?