Have gained more experience of the round rods between the string ball and the underside of the stable. No other type of wood than spruce or the wood that is in the lid (cedar etc.) is what you should use. Hardwood sticks such as birch gives too high volume and too strong attack, in addition with an ugly taste in the tone. With fir plugs you get enough of the clarity, volume and attack you need without changing the tone.

Another thing I discovered is that the small hardwood lid where the string ball rests is important. Without it you will not get the same effect, the surface where the ball rests should be very hard.

Then it is a taste of what you want, but without the plugs you get a low volume and soft guitar that is not aggressive and clear. If you have sensitive ears like me, it is not entirely certain that the plugs are the best option in all situations. You can of course learn to be easier on the hand and bring down the volume that way, but the hard attack still remains. I myself will have two guitars to choose from, with and without plugs.