Double Top implies that there are simply two components to the soundboard, two independent soundboards glued together under pressure. In actuality all double tops are three layered; the inner top, outer top, and a middle core which at this time is usually composed of wood, Nomex Honeycomb.
Maestro Guitars was awarded the patent for Double Top Acoustics guitars in 2013. The advantages of having Double Top guitars are the clarity of the individual notes, much more sustain, better balance and an improved projection in front of the instrument, as with the Nomex Honeycomb core, it makes the top lighter while maintaining structural integrity of the guitar. Even a small bodied instrument can fill the room with ease.