Room Treatments for L Shaped / C-shaped room?

[jmdesignz2]

So I started with wondering if I should get different speakers and with a few tweaks I was able to get Much better sound from my existing set up. This started my journey for room treatments and brought me to this question - how much difference would room treatments get me? I suppose I need to do a room measurement...but perhaps someone else has had to deal with a similar space?

 

My listening room is fairly large and a complex shape due to shared spaces.

 

From above, It's like a large L

 

where the speakers are situated at the top of the L

 

but there is also an open doorway at the rightside/top of the L which leads to a very short /round hallspace to 4 doors>3 rooms and a closet. All closed doors.

 

At the bottom right of the L is a long extended space to the dining room which also has a kitchen adjoining that.

 

Top to bottom of the L is 263 inches

width is 138 inches. All ceilings are 96 inches. Berber carpet throughout.

Listening position is 142 inches from the top of the L

Speakers fronts of tweeter units are 40 inches from the top of the L

Tweeter centers are 75 inches apart