I did something similar - I finished the area under my basement stairs, hung monitors from the stairs above me, and put fabric on all the walls for soundproofing.

I have to climb through my storage area, under a shelf, and through a small hole to get in... but that also means I cannot easily get out and take a break. I just keep on working.

Likewise, I am so hidden that my kids just assume that I am downtown in my office, and they do not interrupt my work. And my wife won't come in either, as she get claustrophobic.

I am easily 3x as effective when working from home now.