Door versus "plug"

I've recently aquired a 3 room basement. Between my "control room" and "recording room" is a space where a door should be. I'd like to know if hanging a door is a better solution than making a "plug" or a removeable, smaller wall to fill in the space - is there a technical name for such a thing? It appears from the last 4 hours of reading thru the topics on here that hanging a good door would be better but I'd like to now if either solution would work just as well as hanging a door would be a lot harder than my other solution, i.e., stuffing rock wool between 2 slabs of plasterboard and putting some pyramid foam tiles on either side to keep the sound out. Any help would be greatly appreciated. I've attached a sketch of the layout which I hope helps. My budget is $700. Thanks in advance, Pyxis

Welcome to the forum, Pyxis. :) You haven't updated your profile (the first requirement of the "Before You Post" announcement), which among many other important things will give us an idea of how strict your building codes may be in your area. You may not be able to legally remove that doorway. It may be an emergency egress. That being said, walls typically outperform doors. --Keith :mrgreen: