This video shows how I built my porous acoustic absorber. It is basically a wooden frame around a piece of rock wool, but see it for yourself and learn how to treat your room for better acoustics.
The nice background music is from anoopScoop ( https://soundcloud.com/anoophariharan):
Lightning-Upbeat Background Music [Creative Commons] (https://soundcloud.com/anoophariharan/lightning-creative-commons)
