Solid hardwoods will give you problems with dimensional stability, with wood expanding up to 1/8" per foot across the grain and negligibly with it. Raised panels on furniture are made with undersized floating panels for this reason.
People who successfully use solid hardwood for speakers tend to limit themselves to small speakers, floating baffles, and open baffles where pieces don't have joints with grains at 90 degrees to each other (if it all expands in the same direction it doesn't matter).
People who successfully use solid hardwood for speakers tend to limit themselves to small speakers, floating baffles, and open baffles where pieces don't have joints with grains at 90 degrees to each other (if it all expands in the same direction it doesn't matter).