This manufacturer does not publish specifications for the soundboard material for this model beyond the species of wood. Model to model, these soundboards may have variances in grain density, irregularities, knots, or areas where material was cut out and filler material was glued in to take it’s place. We inspect the soundboards of every piano we sell and encourage shoppers to inspect the soundboard of any piano they may consider purchasing to determine the quality of the soundboard material. Steinway soundboards have a minimum of 11 grains-per-inch and our Boston and Essex pianos specify quality with a minimum of 8 grains-per-inch on every piano.