This question has come up several times, so I’m going putting up this brief post to explain the term “Revoiced.” Let’s start with what it is NOT. Revoiced is NOT just a bracing change.
When one is Voicing a guitar, the thickness of woods is considered, adjusted, optimized. This doesn’t necessarily start and stop with the thickness of the top. Sometimes voicing a guitar goes as far as changing the thicknesses of several different areas. For production guitars it’s USUALLY formulaic, but the point is that Revoicing means that the entire guitar is optimized.
For example, when Andy Powers went about revoicing the 600s, the thickness of the tops changed. A bigger body like the Grand Orchestral (GO) required stronger, thicker top and back to span the enormous relative body. The Grand Symphony (GS) didn’t need as thick a sheet, because it was smaller, and the Grand Auditorium (GA) thinner yet. In the author’s opinion, the GA body is the ideal size for balance of tone, etc. One can tell playing them that the GA back is thinner, feel the bass in the kidneys.
In summary, revoicing is a revision of the existing model, optimizing major aspects of the guitar, not just changing bracing. This usually involves the top, back and sides as well as bracing, and can include other innovations. The subject can be discussed at much greater length, but the summary is the bottom line. This definition also explains why the Taylor 600 and 800 line are revoiced but the 500s, which got bracing changes from Andy Powers for 2016 and even changes in back & sides wood, are not revoiced.
Regardless, when you find one you can’t put down, take it home with you!