Don't be silly! Find a nice rug you like and hang it on the wall from a one inch spacer. Maybe a couple of rugs on different walls (on the floor if it's not already carpeted.
Acoustic treatment question: do you agree with Dennis Foley that $46k to $65k is required?
In a video from 1/29/2021 (yesterday) Dennis Foley, Acoustic Fields warns people about acoustic treatment budgets. He asserts in this video that treatment will likely require (summing up the transcript):
Low end treatment: $5-10k
Middle-high frequency: $1-1.5k
Diffusion: Walls $10-15k, Ceiling: $30, 40, 50k
https://youtu.be/6YnBn1maTTM?t=160
Ostensibly, this is done in the spirit of educating people who think they can do treatment for less than this.
People here have warned about some of his advice. Is this more troubling information or is he on target?
For those here who have treated their rooms to their own satisfaction, what do you think of his numbers?