I was getting a bit of uneven soundstage with having a large 10ftx8ft window to the left side of my room so decided to make a cheap free standing rockwool absorber to move into position when I’m mixing and to use when I record things with a mic.
Sorry if the parts are UK specific only.
First you need the stand. £17 room divider from Amazon.
Then an acoustic panel. £35 from StudioSpares
It’s only 25mm thick as I didn’t need any bass reinforcement. You can use thicker ones but they’re more expensive.
Put the frame together, chop the a horizontal bar to the width of the panel with a dremal then screw some screws in the vertical bars holes and put some washes on to stop the screw from penetrating the rockwool.
I used a small screw driver to push a hole in the bottom of the panel and secured it with some cable ties.
Total cost £65ish. Took about 10 mins total from unpacking.