Originally Posted by jkv
cut a piece of 1/4" plywood the same size as your ceiling tile and attach it to the back of the ceiling tile using construction adhesive. This should provide enough strength to hold the speaker.
You still need to tie in support to the structure above the drop.... it's a safety thing... you are adding weight to a suspended structure that was engineered for a specific weight per sq inch ratio.... adding the speakers, much less plywood is stressing the support.
You can get the additional support wire at one of the big box hardware stores, and tie the "tiles" with the speaker into the hidden cieling above the drop.
Better safe than sorry.
NOW on another note... with all that "loose" metal frame and supporting wires... are you ready for the rattle?