What to Do about a Soundpost Crack
Soundpost cracks occur frequently, and repairs can be tricky
Q I play a Wm. H. Lee deluxe cello that was made in 1998. Recently, during an orchestra rehearsal, someone tripped over my instrument. A crack about an inch long opened up right below the bridge’s foot, the one close to the sound post. I believe it went all the way through, as the surface is now uneven. What effect will this injury have on the price of the instrument and the tone after it is fixed?
—Edward Austen
Biloxi, Mississippi
A Having lived a dissolute life, I don’t remember much from childhood. Adages are mostly what remain of my education: you can’t cheat an honest man, better late than never, once burned—you’ve heard them all. It’s ironic that they are what remains, because experience has proven most of them to be wrong: didactic, rather than insightful. There is one that has stood the test of time, however, and that is the saying that it is the exception that proves the rule (appropriately enough). The rule here is "never diagnose damage without having the instrument or bow in your hands." The exception that proves it is what you describe: there is no question at all that what you have is a soundpost crack.
Soundpost cracks occur frequently—almost without exception as the result of a blow to the instrument. If you think of how a cello is put together, it’s easy to see why. The strings exert a pressure in excess of 50 pounds on the top of a cello. The top, however, is made of spruce, a softwood, and is less than five millimeters thick. That’s plenty to withstand the stress it’s designed to take, as are all the other parts of the instrument—but it is designed to withstand a constant stress. Sudden impact is an entirely different matter. Because of the way the thing is shaped, when a cello lands, it tends to land on its bridge, and then the blow is transmitted directly to the thin, flexible, and easily cracked top.
