I wanted to build a cb kalimba, so I cut some bicycle spokes, some aluminium bar, some hardwood, and made some, It sounded horrible, damp, noisy, lots of unwanted harmonics, etc. So, I thought, maybe the tines are bad... I took my old and "authentic" gourd kalimba, and changed the tines: the old, ethnic kalimba sounds good with the bycicle spokes, and my cigarbox one sounds bad with the kalimba tines.
I changed the metal parts, and the result was the same. I went then to the local ethnic instruments shop, and try a lot of kalimbas, professionals and amateur builds, and I came to this conclusion:
The kalimba don't really need a hollow resonator box (of course, it amplifies the sound, but not crucial)
The kalimba needs a quite thick, firm base, to resonate properly, Maybe its because the tines are thicker and harder than a guitar string, There are professional kalimbas with no hollow box, only a hard wood block as base, and they sound fine.
So if you want to make a cb kalimba, you have to put a hardwood block on the box, or change the box lid to a thicker, firmer one, or use a thicker box. The thin boxes just won't work (at least it didn't work with me)
I would like to know your opinion in this!