I am often asked, "What are the different tonal characteristics of wood species for use in tonerings?"
There is a traditional story about famed violin maker Antonio Stradivarius. When woodsmen felled spruce trees in the Alps, the easiest way to get them down the mountain was to let them slide down on the snowy mountainside. It is said that Stradivarius listened to the logs for a certain whistling tone as they slid. When he discovered a log with that quality, he bought it on the spot.I don't know if that story is true, but it encourages me to use my ears when I go out to buy wood. I often select lumber that suits my ear over lumber that pleases my eye. I use what I call the "plink" test. If I'm out and about, my plink tester is my fingernail. By flicking my fingernail into a piece of lumber, I get a very good idea about its resonance.
You've heard of the mind's eye. I believe we all have a "mind's ear" as well. If I get an inspiration about a combination of woods, or a combination of material, type of towering or rim diameter, I often find that what I imagined was borne out in reality. There's a lot of common sense involved, too. Dense wood equates with higher pitched "plink" in a tap test. When I bought my first Maple from Timeless Timber, I was gratified that it tap tested with a purer tone than common maple. Common sense would suggest that denser woods create brighter tones, and it turns out to be true. You'd probably guess that a mahogany neck will warm up the sound of an overly bright bluegrass banjo... and you'd be right!
Wood under tension is more resonant than wood that is not. Piano soundboards are flexed to create tension. Most folk and bluegrass guitars have the strings anchored to the sound board, pulling it into tension. Jazz guitars do not have the booming bass of a Martin D-28 because they strings are anchored to a tailpiece and do not stress the sound board to the same extent.
As I state in Block vs. Laminated Rims, it is too easy to get caught up in thinking about single factors. Rim diameter, thickness and depth are very important variables that will make two rims built with the same species sound very different. Add to this, the variables of head material and head tension and you will find the exact wood species in your rim is just one of many factors.
I believe it is possible to aim for, and achieve your goal in the spectrum of possible banjo sounds. Use your "mind's ear" and trust common sense.
I have ranked woods that I have experience with below. I have used the common names as found in the Woodworkers Source Wood Library. For those of you who want a "real" answer, here is a list of woods that I have actually tried and their rianking:
|2||Rosewood (Honduran, Bolivian, East Indain), Cocobolo, Granadillo (Platymiscium genus), Tea Tree (Melaleuca Species), Ipe, Jacaranda.|
|3||Padauk, Purpleheart (I no longer use these, but some makers like them)|