Having a bit of info on how woods change or color a sound goes a long way in making an insterment with a desired sound. In the following the words soft and hard ar not ment to classify a wood type such as a hardwood or softwood. They are ment to mean more of a density or mass term.
A soft wood such cedar will tend to soak up the high notes without affecting the lows very much. A redwood is a bit harder so there will be less of that high removal. A hard wood such as say rock maple will tend to reflect the high notes while asorbing a bit of the low.
That being said when you yse a soft wood on the top and a had wood on the back of an insterment the overall effect is a reduction in hearing the high notes. Reverse them and you will get the oppsite effect. Using a really hard wood for the sides will have a different effect than using the same wood as either the top or bottom.
While there are many more things that affect the sound such as wood thickness, shapes, sound hole size and placements, etc to consider wood choices are something that have to be considered. Always use properly dried wood. In my oppion kiln dried is not a proper drying. If you can keep wood properly stored for a year or 2 before use the esults will be far better. Just buy a bunch of the kiln dried stuff and stash it up in the rafters for a year or so then you will have decient wood.
