I've found that harshness can be from various factors. One thing you can try for cheap is to listen off axis (i.e., point the speakers ahead instead of towards your ears). Also, quality of power can be relevant as well, you might want to look into power conditioning - I found that something like the Shunyata Denali definitely makes a difference. With regard to your room treatment, I don't see anything that indicates that you have treatment at the first reflection points on the side walls or ceiling. Also, I assume you have a think rug or similar covering the floor from the speakers to you because that's important as well for reflections.
Taming the high frequency
Looking for ideas/suggestions to tame high frequency harshness. Recently installed a Lexicon MC 12 processor after my Krell decided to go to the electronic graveyard. Since I did not have this issue before I'm assuming the Lexicon is more revealing. My dedicated listening room is 15X23x8 and is treated with GIK 244 and 242 panels along the front and rear wall at ceiling junctions and Accurex bass traps in the corners floor to ceiling. Along the front wall behind the speakers are some decorative thick blankets for absorbption. No slap echoes anywhere in the room. Room is dual purpose H/T and 2 channel stereo listening with separate systems. Systems consist of Proceed Pre, Adcom 555II Amp and B&W 803d speakers for 2 channel and Lexicon Pre/pro, Polk speakers for H/T and Emotiva XPA amp. How can I diminish the high frequency harshness I'm experiencing? Any ideas or realistic suggestions?