Sound Hole Placement
Instruments- discuss specific features, luthiers, instrument problems & questions
Dulci-Clan -- Once again you're getting lost in nearly meaningless details, and over-complicating things.
Overall shape (hourglass, teardrop, elliptical, trapezoid, etc.) has no discernable effect on dulcimer sound. I have a standing offer of $100 to anyone who can pass my blind listening test and tell which instruments are playing (I play some tunes on some dulcimers and send you an MP3 -- you tell me what shapes are playing what tunes).
There are well over a hundred factors that affect the sound of an instrument, and the kinds of woods used for sides/backs/tops are pretty far down that list -- not even in the top 10.
Soundboard placements? The dulcimer has one soundboard -- the top.
Do you mean fretboard placement? The dulcimer has its fretboard running down the centerline of the top, by definition (unless it's a courting dulcimer with two fretboards evenly spaced across the top. Fretboard overlays do not effect sound, but they do make it smoother to play.
Once again, soundhole placement does NOT effect sound quality. It can effect sound volume, but as a beginner you'll not notice anything.
People like Dulcimore Dan, Ron Gibson, myself, Kusani are giving you the benefit of our several decades of practical experience as builders and players, and you seem to be ignoring it.
I don't want to sound harsh or uncaring, but please -- take Matt Berg's advice: Go play a dozen different dulcimers for 10-20 minutes each; take plenty of notes about your experiences, and then get back to us.