Do you want soundproofing or room treatment?

For soundproofing you will need to rip out your current sheet rock.

For room treatment there are several commercial products available, and DIY sites out there.

Sound "treatment" can be as simple as hanging heavy drapes or packing blankets on the walls. You can buy foam room treatment kits but they can get very expensive. You can build your own bass traps, difusers, etc. for much less.

The first thing to decide is what you are trying to accomplish. As gdoubleyou said, sound PROOFING can be really, really expensive and involves building walls and floating floors. Getting rid of echo and room resonance is easier and can be done on the cheap.

I built my own diffusers and bass traps and they work great and not expensive at all.

how did you build them and what did you use to do so

Josh1115, post: 374058 wrote: how did you build them and what did you use to do so

I built 4X4 difusers and bass traps using peg board. I had read some articles on using pegboard as a surface with rock wool bat insulation as a filler. I built a 4X4 frame out of 1X4 boards, layed in bats of 4" rockwool and covered it with a sheet of pegboard. After painting I hung them on the walls.

For bass traps I used the same idea and put the pegboard in corners and where the wall met the ceiling. The bass traps are 2 feet wide and 4 feet long and filled with rockwool bats.

I also added three inch foam squares to the back wall where my monitors point and along a side wall that is close to my right side monitor speaker to cut down on reflections.

All in all it saved me some money and they work just fine. Of course, I also have 12 inch thick floating walls built on staggered studs with resiliant channel and double sheetrock layers, a floating floor and a ceiling with double sheetrock layers hung on resiliant channel and topped with 42 inches of blown in rockwool.

Not a bad room overall.