So, right now I have two SA-12s [as any car audio rookie that has evolved past kickers would have] and am working on my sealed trunk build, and just noticed I have enough room for a 3rd 12, however, it wouldn't fit in the sealed off part.. the cabin trunk access isn't big enough for three 12s plus port, would it sound just awful if I had one in a box in the trunk, then my sealed off box hosting two 12s.

I would imagine so, just curious however.