To try and be more helpful. I wrote this Kitchen Table Sound Studio.
https://forum.audacityteam.org/t/too-compressed-rejection/52825/22
That’s the idea, except in the closet, you can cover all four sides and don’t forget one folded up on the floor. For extremes, double it up. That’s what this is.
Each of those walls is two layers of blanket. On the upper left, you can just see there’s another blanket back there. That was a sound shoot for animated movie voices. That’s probably overkill for you. I was shooting in an industrial park.
You can hear this happening. You walk from the house into the “studio” and listen to the natural noises vanish. Most people never have to get good at that, so when they record, they have big room echoes and the refrigerator in the background.
Koz