Friday, August 3, 2007
What is Going On When the Kalimba Buzzes?

Usually the kalimbas makes a very pleasing sound, but every now and then the thing buzzes and makes a nasty. We can fix the buzz with paper (see the earlier Friday tips). It is actually common for kalimba players not to know how to fix the buzz. Some players want the buzz. But even if you do, you should know how to fix it so you can tailor your sound in whichever way you need to.

Here is an example of a particularly nasty buzz.

Now, wouldn't it be great if we understood why the kalimba is making such a nasty noise? If we did, then maybe we wouldn't have to listen to it!

When the kalimba rings clear, we get lots of harmonic activity for just the first 0.1 second or so. Lots of high frequencies, this is the "click-y" attack of the instrument. But then after 0.2 seconds, the sound is dominated by a fairly pure fundamental tone, plus less energy in the vibrations of the neighboring tines, which will harmonize beautifully with that fundamental, provided your kalimba is in tune. I think of these neighboring sympathetically vibrating tines as "pseudo-harmonics" - they are indeed part of the sound of the kalimba, even though they are not produced by the vibrations of the tine you struck.

On the contrary, the sound of a BAD BUZZ are all due to the misfortunes of that poor tine you struck!

Here is the spectrogram, i.e., power spectrum as a function of time, for this nasty buzz. Can you tell what is happening?

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