Tone woods: sonic signature
There are a number of factors that determine the tonal properties of wood. In addition, tonewoods respond differently in the hands of different makers. They can also take on different characteristics when used in different models of guitars - even those built by the same maker. Whether a particular wood sounds good or bad ultimately depends on who is doing the listening, so any attempt to sort out distinctions can only be subjective.
Perhaps the most important factor a luthier must take into account is velocity of sound, which refers to the speed at which a material transmits received energy. A luthier must design with materials that facilitate the transmission of vibrational energy. Lively materials, those with a high velocity of sound, or low internal damping make the best facilitators.
Most luthiers (though not all) believe that the wood chosen for the top is the single most important factor in determining the quality of tone of the instrument. It is also interesting to note that the wood itself takes on different characteristics depending on which part of the guitar it's used for. Makers of electric guitars with bolt-on necks have long been aware of the fact that neck and fretboard materials can have a significant bearing on tone. Bridge materials, like fretboards, cannot make or break an instrument, but they serve to enhance or edit the tonal effects of other woods in the guitar's construction.
