Sound quality of a harp according to conventional wisdom: lighter wood (cherry) has a brighter and more focused tone whereas darker wood such as walnut and bubinga, produces a more mellow and distinctive tone. However, if you ask different "experts" for an opinion, you are likely to get different answers from each. Experts use various adjectives to describe sound.
Some folks choose a harp strictly on the basis of how it fits into their home decor but most care primarily about its sound. One thing is certain - the ultimate test is how the individual person perceives and likes the sound. This is what makes choosing and buying a harp such a subjective matter; it is a very personal choice since there are no two harps that sound exactly alike. Each harp has its own "personality".
No matter what kind of wood is used, all harps improve in sound quality as they are played, which is also the case with most other fine string instruments as well. Their sound improves as instruments are played and broken in. The sound of a harp usually reaches its full maturity after several hundred hours of playing or 1-2 years. Its sound won't change noticeably thereafter.
One can visually notice the maturing of the harp as the sound board will slightly bend (or curve) in time due to 35-50 pounds of constant tension per string 24/7. The design of the sound board and edge grooves provides for the curving ability since the sound board sits loosely in sound board grooves to allow the bending. The bending of the sound board is a natural occurrence and is part of the maturing process. Usually, after about a year, the sound board will stay firm. At this point the sound of your harp has matured.
The sound board is made of "Baltic Birch", a high quality, composite six-ply laminated board grown and manufactured in Northern Finland. The board is extremely strong so you will never have to worry about a broken sound board. Its high density and relatively short fiber, due to a short growing season in Northern Finland, are positive properties for producing good resonance.
Type of wood, wood grain, wood density and how glue is applied are just as important as the design itself in producing and influencing the sound. That's why some folks say that building a fine musical instrument is a craft and an art.
The actual color of the cherry becomes darker as the wood is exposed to daylight. Cherry wood usually turns into an attractive, reddish color. The color walnut hardly changes over time.
22 String Irish/Celtic Lap Harp "Brittany"