Metal cabinet speakers

It would be a tiny cab if built out of a 1/2 sheet of ply.

9”w x 15”h x 12”d with one internal brace.   I taper mine from the 9” from to a 6” back.  There is virtually no waste but this is a pretty typical cabinet size with an internal volume of ~.45 cu ft. Though it varies slightly depending on the size of the port needed. 

Is a big potential disadvantage of metal speakers like magico q7 or yg sonja that if there is any loose bolt, nut or screw it could rattle in the cabinet ?

Rockport makes some heroic cabinets and other high end brands competing for the same dollar are making inert cabinets. I had a pair of usher be20 dmd’s 285 lbs each that The previous owner replaced the spikes with flat plastic tiles to ease sliding around. I peeled the tiles off and installed the spikes and the bass quality went from a 3 to a 7 in regards to speed and detail. Same cabinet. If aluminum is your thing, cool, but there’s other designs equally capable, just check magico’s website