To tie that together with the B&W graphs, once one gets a little off axis, things behave in that nice way.
I've been thinking to make a separate thread on the DIY construction methods of hanging acoustic panels, currently none exist, I've searched AVS forum.
Just these for Fabric frames, which are integrated as part of the wall itself, not hanging and locatable to where only needed.
(these are great threads btw for those whole wall coverage methods)
Fabric Frames - GPowers Thread
Another Fabric Frame Thread - Canvas Stretcher Bars
I'll start it later, and others can then add their methods there.
IMO, this "Master treatments" thread is more for the theory, science, and practical application for acoustics of your particular room situation/issue, not the DIY construction methods, that will clutter it too much.
Having separate DIY construction technique thread will keep that ready for others to grasp as well, this 100's pages thread can be overwhelming at times.