maghister nailed it
another area is your cd transport. Get Machina Dynamica New Dark Matter to absorb laser scatter inside your transport. It’s a BIG deal, as is his isolation springs
Also, I have a 105; go to ebay and get replacement incoming wire loom with Furutech rhodium IEC AND upgrade your power supply. I got the < $120 version. This combo put a lot more meat on the bone, fuzz on the peach...
and yes, room correction as well as subwoofer placement . See YTVs with’ Acoustic Fields’. His subwoofer placement ideas are radical, but they work!
WireWorld Cables new 8 series are huge. and offer in home trial
If you haven't time to go all XLR; good place to start is 105 to amp
After doing some of these things dust off some of those audiophile discs. you may like them now
hth