My mains and center are 16" from the wall. The mains are towed in to come across 6" from the side of your head. If i increase the treble from 2.5 kHz to say 5.3 kHz will that help out with the treble some? If i blast the system it really does sounds fantastic with treble etc. Unfortunately i can't go that loud because the living room is not real big. It is just a average size room. I also noticed when i changed my speaker crossover from 80 Hz to 120 Hz it made the speakers sound better at higher volumes. I noticed when i really crank it i lose 99% of the distortion and they sound awesome. It is just too loud for this room. My volume goes from 0-50 and 25-26 is loud in this room. When i turned the volume to say around 30 the speakers sounded better with the 120 Hz crossover. Any suggestions with the speaker crossover settings for a lower volume? The 120 Hz crossover has more distortion at a lower volume especially out of the center channel. The scene i was listening to for distortion was Jurassic Park 3 in DTS. The T-Rex has a real bright roar when they stumble upon him while he is eating. When the volume is at 29 or 30 it clears up that scratchy static on that high pitched roar. The center does have more mid range because it has 4 woofers instead of 2 like the mains and surrounds.
I'm not really following your setting with your EQ. Is the frequency you're listing the frequency that's getting boosted? If so, then boosting at 5 kHz would probably help more. I pulled up the manual from the most expensive "Sony" branded receiver currently sold and it didn't say much about the EQ. Sorry, I can't be more helpful without knowing the model of your receiver.
As for the crossover settings, your speakers don't extend very deep. Assuming the numbers you listed above are the -3dB points, you'll want to cross over at at least 100 Hz and maybe as high as 120 Hz. This relieves the small speakers of the low bass and lowers distortion by preventing the driver from working too hard at higher volumes. At lower volumes, it could be distortion from the sub playing too high or undamped driver or cabinet resonances that get masked at higher volumes. I really can't say though without knowing what brand and model your speakers are.