Oh and my Epi isnt very big/resonant sounding when its unplugged for some reason. Probably cr@p/cheap woods or something I guess.
I think the Epi problem is there may be so many pieces of wood preventing it resonating, I had one a while back and decided to refinish it only to find the nightmare that lie beneath. 1mm thick maple veneer over roughly carved Alder made up the top, 7 pieces of low grade mahogany sandwiched together in no particular order so the grain didn't flow or match all covered in a 1mm thick mahogany veneer so that it looked pretty. I've heard that they are better than they were around 1998 so this may not be the case with yours, and the proper Gibson Les Paul Custom I had was very quiet also unplugged.
I suspect the way the bridge is fastened to the body makes a big difference, Both my Epiphone and my Gibson had threaded inserts in the body into which the bridge posts screwed, on my Greco they screw directly into the body, aeshetically not so nice perhaps but you hear the difference IMHO.
