Metal cabinet speakers


I like the idea of a very strong inert metal cabinet. Besides Magico, Steinheim and T+A.. who else makes metal cabinet speakers?
smodtactical
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 
My question though is if someone had an issue with a loose bolt/screw that would rattle in a metal speaker?
" @mijostyn, A D'Appoltio Array uses a 3rd order cross-over not a 6dB 1st order cross-over. "
I happen to have discussed this subject with Dr. d'Appolito.  I was considering building a set of DIY speakers based on a Dynaudio design for DIY,. the Myrage.  The system used first order crossovers.  I called up Dr. d'Appolito at his home and asked him about 6db crossovers for his array.  He told me that a d'Appolito array functioned as designed with any odd order roll off slopes, but that he was personally partial to 18dB slopes.