External Speaker Cabinet Mounting Bracket for Mounting Speaker Cabinets on Speaker Stands. What do you do if you have a speaker cabinet that does not have a built-in speaker mount socket, but you'd like to use it on top of a tripod speaker stand? Simply install a BMB-200K to the bottom of the speaker cabinet, and you're set! The BMB-200K is an external mounting bracket for speaker cabinets that do not have built-in speaker mount sockets. It mounts on any flat surface with included installation hardware.SpecsExternal bracket securely mounts any speaker cabinet with a flat bottom on a (1-1/2") (38 mm) speaker stand tubeMeasures 4" x 6" (102 mm x 152 mm)All hardware included for installationGlass-reinforced polycarbonate fitting holds 100 lbs. (45.5 kg).