Help. System sounds thin and bright or harsh

Room treatment is on the agenda.  I went through this in the old place with stacking four foot bass traps in corners behind the spks and a massive wool and canvass behemoth behind the couch and an absorber on the wall just behind the seating position. Overdamped to say the least for the 30.1's. Had been trying to tame Harbeth slh5's that were just way too boomy for my apartment. With the 30.1's I took out all the treatments cept for the trap behind the couch and the absorber behind the seat and found I liked the sound much better. Going to try simple cloth or rug options in this new room just as a test once I determine that all the components are performing up to spec.  I've already checked out treatments for the first reflective points on the side walls. Wanna keep it simple and relatively cheap.

Someone mentioned toe in.  I barely have any at all. Adviser at Fidelis that distributes Harbeths said to point them directly at me with hard toe in.  No bueno in this room.  They are not firing straight out but I can see all of the inside walls on both spks.  Not sure if many have purchased the "Get Better Sound" book by Jim Simith.  It's loaded with all sorts of "free" tips...many which I am just up to tackling and sdI still am having problems.. 

Just pushed the harbeths closer to the front wall (from 3' 2" to 2'2")  tried before and after moving seating position forward. First impressions are it sounds a lot worse.  No increase in bass. This seems to run counter to the laws of speaker physics. LOL.  "Something" seems to be sucking some of the bottom end out.  I'm not a bass junky either and I realize the 30.1's bottom out at 50HZ. Excellent recordings are still tolerable but jeese this is crazy.  I am noticing that the volume is a lil higher to get the same sound level. That's a lil odd. So I'm compensating for something with the volume control. Maybe things are a little less lean...but not as loud.???  Isn't this fun!!!

Happy listening

I'm not familiar with your speakers, but FWIW since you're moving them around....

IME, floor and bass driver interface (distance between the bass driver and the floor as well as the side walls) goes a long way in determining bass reinforcement. I think someone suggested tilting back your speaker already but lowering your speakers height, which may seem counter intuitive, off the floor in combination with the tilt would make a better bass response. What I would try just to see if lowering the speaker would help just get them up about a foot off the floor (and tilted back so the tweeter axis is pointed at your ears). And go from there. BTW if you want to keep the sense of depth of image keep them as far away from the back wall as possible.

In my room traps and absorbers behind the listening position did not work out so well. 

Scott, @verdantaudio, mentioned it above. Swap components out.  Doesn't the Oppo have volume control? Or does it get disabled with the mods? If it still has the volume control remove the preamp and see how it sounds using the Oppo as the "preamp". I find it hard to believe there isn't something else going on with either a component or the speakers so I would sub out preamp first, then amp (if you have anything at all, even an old receiver) then sub the source. I have those Harbeths and have used Pass stuff with them. You could use dental floss as cables and it won't sound as bad as your saying. No way any decent quality cable will make that huge of a difference unless your listening at like 110dB. There's something else going on.