Mon frere,
Welcome to Gearslutz.
I just posted some information for another chap over here:
Room Acoustics .....again, regarding room treatments. You may want to check that out.
In essence you need the following as a minimalist approach to room acoustic treatments:
1. Farbric that you like and can live with. (More pourous=more absorption at higher frequencies)
2. Acoustics medium: Rockwool (cheap), OC703, not as cheap (either will do)
Mass and thickness (among other things) determine the amount of absoprtion at lower frequencies.
Cut the fabric to the correct size for wrapping your panels. You can use velcro or some sort of mastic, spray glue, etc to secure the fabric to the acoustic medium.
Correct placement of your traps in your space. If you can supply pictures of your space here, or sent to me, I/ we can help you more.
I hope this helps.
Cheers,
Joel DuBay
Ready Acoustics
DIY Bass Traps and Acoustic Panels