Bass Trap Question(s)

I've been doing my research and digging through the internet and yellow pages for some companies locally that sell some insulation products I can use in my DIY traps (if I decide to build any next month, I plan to). In the end owens corning might be too expensive so I'll probably end up with some alternatives from johns manville or some other brand. I plan on picking up the lumber for the frame from home depot or lowes and getting the fabric from either hobby lobby, joann or hancock fabrics. I'm somewhat confident I will be able to find the core material from some local insulation suppliers so that's out of the question. However I'm having a problem figuring out exactly how I should build them.

I seen a tutorial where one was made with the insulation was actually sitting outside of the frame and the frame itself served as an air gap behind the panels, then fabric was wrapped around the entire unit.
I'm interested in an approach where I can layer up two 2" panels for a 4" thickness total and building my frame actually wider than 4" so I can have an air gap for additional trapping. Instead of placing the panels on the outside I want them placed inside so I can have a nice sturdy frame protecting it. I figured this would make it easier to handle and less bulky. The problem I found with this though is since I will have a few inched of an air gap within the frame, what can I use to keep my insulation from sliding around once I wrap the panels? I don't want my insulation sitting loosely lol. Would I be able to simply drive some nails through the side of the frame into the insulation to hold it in place, or could this damage it or maybe affect the performance of my panel?

Someone please help me with this fallacy.
 
Back
Top