The latest development in my design quest for ultra light weight hammer dulcimers is the Arch Back Compact. This design enables me to build dulcimers with wood soundboards and carbon frames, or all-wood dulcimers, that are as light as an all carbon fiber dulcimer. Weight is 10.0 lb. with carbon frame and about 10.6 lb. all wood. The tone and tuning stability are excellent while avoiding the much higher cost of all-carbon construction. They are durable, trouble free, and I love the tone.
The arch design allows the middle of the dulcimer to be very strong, to resist string tension, while unnecessary excess weight is eliminated toward the pin blocks. Tone is very articulate, clean and clear. Sustain is well controlled resulting in less muddiness for rapid musical passages. For sophisticated, wide range dulcimers that are truly ultralight, the arch back concept appears to be the most cost effective approach. I am now experimenting with arch backs on larger dulcimer models.