Just in case anyone reading this is curious about relative volume, here's a simple video. Please remember that I am not, at this time, a kantele player. I hope to be able to consider myself a player before long, but I am only as far as being able to tune and sort of form a couple of chords. A good player can get a lifetime of music out of those 5 notes, but I'm not even close to there yet.
Still, if you just want to hear the volume difference, the video will illustrate.
I actually suspect that the new kanteles would be a little louder if I used metal tuning pegs like with the practice board. The wooden pegs may have a slight dampening effect on the strings. I could be wrong about this, though. I'd have to make another with the tuning pins to find out.