On Designing and Building a set of Marimba Bars
----- Original Message ----- From: "barry anderson" To: firstname.lastname@example.org Sent: Tuesday, February 19, 2002 1:52 PM Subject: re bass Marimba key lengthsHi Jim,
I'm trying to build a bass marimba using Jon Madin's book. Unfortunately the woods available in
NZ are quite different in density and elasticity (and I'd like to use recycled native hardwood for the bars). Is there any formulas for calculating bar lengths based on density, or modulus of elasticity or something?
What's the process when you design one? I realize that these questions are (or could be) rather involved, so alternately any direction to a book or whatever would be greatly appreciated as
I'm creating a lot of firewood and grey hairs at present. Thanks in advance for any help, as
I don't think there are any other marimba makers in my part of the world.
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Hi Barry - good to hear from you!
There is good news and bad news for you, when it comes to using alternative timber for marimba bars.
Bad news one - The only two timbers that are both hard enough to handle the beating and really good sounding are Honduras rosewood, and African Padoak. Any timber will produce some sound, but it will all be of varying qualities. I have heard some marimbas made from all sorts of alternative wood, and some of them are pretty good though. The trick is to find a variety that vibrates longitudinally well - that is along the length of the grain. The marimba makers in central America climb into the mountains, and go around tapping trees to hear what they sound like. Some of our Australian Native hardwoods one would think might work well, but when you hit the wood, it sounds as dead as a dodo. Even cheap pinus sounds better, but tends to be too soft for a useful bar.
Bad news two - There is no fixed formula for bar length I'm afraid. Every timber has different properties, and even one tree might be different from another, or wood from one particular part of the tree different. The essential thing to remember, is that we are working with a medium where every piece is unique - changing grain, variations in density etc - its all part of natural tree growth.
Hope some of this has been helpful.
answers by Jim MCCarthy - 21/06/01
For more help on marimba building you can email Jim.