A.R.E. (Acoustic Resonance Enhancement)
A.R.E. (Acoustic Resonance Enhancement) is an original wood reforming technology developed by Yamaha.
Through precise controll of temperature, humidity, and atmospheric pressure, the molecular properties of the wood can be manipulated into a more acoustically ideal condition, similar to the molecular characteristics of woods in instruments that have been played for years. In NX Series guitars, this treatment results in a sound close to that of a vintage guitar that has been played for years. It produces a sharper tone while simultaneously controlling dissonance in the high range.
Instruments that have undergone this process have received high marks from a great number of musicians. Their evaluations are nearly identical to those for guitars that have been played for years, and their comments often include terms such as "well settled", "mature", "warm", "excellent resonance", and "clear"

Rosewood
Rosewood is a tropical hardwood that has long been the material of choice for acoustic guitar sides and backs. Harder and heavier than maple, it provides firm support for the guitar's resonating top and delivers rich, well-balanced overtones. Its warm quality is perfect for nylon string tone.