The KLH 5 has a couple of nasty resonances slightly below and above 20kHz. Also a rock&roll bottom with a quick fade. What music genres are preferred?
See KLH Model Five loudspeaker | Stereophile.com and KLH Model Five loudspeaker Measurements | Stereophile.com
Have you tried lowering the Mid-HF to Med or Lo? Back in the day, we would tape a thin cloth or a single ply tissue over the tweeter to help tame the highs.
If possible don't have the seating close to a wall... and dampen the rear wall so it does not reflect.
The subs have no phase and only a polarity control, making integration a bit more difficult. Their output @ 30Hz is only slightly better than the 5's. Perhaps try putting the subs in the corners, mid side wall, mid front and rear. IMO, integration of the 5's and the T7/x will be difficult as neither has the required mid-range support.
See ieLogical SubterraneanHomesickBlues for a screed on sub integration.
I'm really curious how the components were selected.
And what speaker cables?