Bert brings up another point. When you try different woods, especially for soundboards, the bracing DOES change to some degree. Cedar is most often found on Classicals whick have less stress on the top and are generally "fan" braced whereas steel string instruments are braced in some form of "cross" pattern. The notable exception to this is Jean Larrivee's instruments which differ greatly from Martin, Taylor, and others.
Mucking about with bracing and top thicknesses can alter the sound of any instrument. The problem that the builder encounters is in the R&D of experimentation, ie. the COST of trying something different. If you're Martin, its not nearly so significant to you as it is to a small luthier. In Hammered Dulcimers, I'm sure that Dusty Strings has a whole helluva lot more money than I do to try such things. There have been times that I've watched the unsalvageable parts of an experiment gone bad burn up in my fireplace and considered just tossing in another $100. for the time. Its very hard to experiment if you ain't got that Do-Re-Mi! But if you really like it, you just chuck it up to experience and learn from it.
The other obvious factor is that sound quality is not only related to woods in the body of an instrument. What is used for the bridge, saddle, nut, fretboard, bridge pins, STRINGS, etc. and what design of bridge are you using. In Hammered's you talk about rails, caps, bridges, rail transfer supports, string gauging, downbearing, and HAMMERS. Even the simplistic App Dulcimer has a number of other things that must be taken into account.
BRW vs. IRW ---- C'mon, gimmee a break...........