Re: using wire mesh to shape fibreglass?
Your idea would work, when done properly. For one, fiberglass is strongest in curved areas, so building a completely square box out of fiberglass sort of defeats the purpose. Two, for what you're doing it would be easier to just use fleece or something of the like instead of wire mesh.
Also....I'd recommend not installing your component speakers on the same enclosure as the sub, even if they don't share airspace. It will create lots of imaging problems and won't sound nearly as good as it would look.
"The world is full of people who want nothing short of perfect,
but settle for less, blinded by their quest for purpose."