Tuesday, January 22, 2008
Setting Up Your Kalimba
Fixing the Buzz - Method 1

I am pretty sure that the buzz in a kalimba tine gets excited by the back and forth sawing motion which the tine makes over the bridge.

The main motion of the kalimba tine is up and down, but the part of the kalimba tine between the bridge and the backstop is also moving—down and up (i.e., opposite to the motion in the main part of the tine). As the part of the tine between the bridge and z-bracket bulges, the arc length of that part of the tine is a bit longer. In order to be longer, it borrows a little from the main part of the tine—in other words, the tine slides up towards the z-bracket just a wee little bit.

This sawing occurs at a frequency exactly twice the frequency of the fundamental vibration. You can read more about the frequencies of kalimba vibrations in the Friday tips series. Anyway, I am pretty sure that the above-described sawing motion is what excites the buzz that Hugh Tracey kalimbas sometimes display.

Why don't all the tines show the buzz? I think that most of the tines just sort of slip on by without exciting a buzz. It is as if some of the tines have something like rosin on them - something that makes the tine stick-slip-stick-slip like a bow on a violin string. There may be some issue with the particular spot of the tine which is contacting the bridge, or with that particular spot on the bridge where the buzzy tine meets the bridge.

A first experiment you can do towards understanding and fixing the buzz is to move the tine a little bit to the left or right and seeing if that fixes the buzz. Think of this as trying to avoid a part of the bridge which might excite the buzz. Move a bit more and see how that affects the buzz. If you find a place where the tine no longer buzzes, you may have fixed the problem. On the other hand, you will need to straighten out the rest of the tines so that they are uniformly spaced left to right - and you'd better not run into any more buzzes on the other tines. For buzzes on the outer tines, or the higher notes, this is the preferred method for fixing a buzz—if it works.

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