How important are the Speaker Cabinets?

Thanks Drew. The questions here are not suited for short answers, but you've put it in a nice nutshell.

It's a very complex subject. You can get a reasonably good broad based understanding if you dig for it—lots of resources on the net and in the library.

In another nutshell, material and mass are very important for reducing panel vibrations, which are very detrimental. This is why open baffle or cylinders are far superior. Instead of using brute force to fix a problem, eliminate the problem from the start.