That's cosy. Looks like you pack a lot of gear into there.
I'm fortunate to have a room dedicated to my stuff, a real man cave. We built our house some years back and I specified a study. I got an Ikea Jerker desk that was very expandable. It's a shame they stopped doing it. There are guitars on the wall and amplifiers piled in a corner. Now I am accumulating drumming gear. I can make some noise in there without annoying my other half too much. I do not have specific audio treatment, but it is not too bad.
I did a post about it a while ago. It keeps evolving.
!PIZZA !LUV