Changes in relative humidity curl the leathers. New leathers take a while to be flexible enough to produce a good sound. When opening the instrument have a look to the wooden mounting base. This plate often is broken. But since the sound is not coming out from the wooden parts this means only extra air consumption and may be glued in the last case.
Many players think it is of great importance the wood used for the housing.
Therefore it has no influence on the final sound. However the housing of the left hand has an important damping effect to lower the sound level. They are the heart of the instrument and the most valuable part and which defines the sound. This is nearly fix and the following thought only for you as an information. There is still a great discussion concerning the material of the reed plates.