You can make frame-less acoustic panels like we made earlier for the window plug, glue some velcro on the back with a very thick glue like Liquid Nails. Or you can make acoustic panels with a wooden back or thick wooden edges and staple the velcro strip to the back with a staple gun. The acoustic panels from ATS Acousitcs have a thick wood strip on the back edges making them perfect for stapling Velcro too.