Q: Experience and all instrument makers tell us that the choice of wood affects the sound of a bass. Of course we know and feel the difference of alder vs. ash bodies, ebony vs. rosewood vs. maple fingerboards, and so many other differences. But, do we know why exactly this affects the amplified sound? What we deal with are metal strings vibrating in the magnetic field of pickups (not talking about piezos). The resonances of the body should not be captured by the pickups. I imagine that the construction of a bass affects, for example, the sustain. But this is not about wood. So what exactly happens here? How would a physician explain this? Does the wood affect the overtone structure of the vibrating string? Voodoo? Black magic?
A: As this is not in my area of expertise, I decided to send this week’s question to my favorite luthier, Pete Skjold, the guru behind most of the basses I play these days and well respected within the bass playing community. (You can discover more about Pete and his instruments here.)
Here is what Pete had to say:
These are general terms, so keep that in mind. Different density of wood produces different results, because the woods vibrate at different frequencies. The string receives these frequencies (which we call tone) and then the pickup reproduces these frequencies based on it’s own ability to reproduce the sound into an electrical signal.
Generally, the more resonant the wood, the broader and smoother the tone will be from the lower to higher frequencies. The denser the woods, the more you’ll get a more focused, narrower frequency band.
Knowing which woods generally produce a certain frequency range and tone will allow a builder use the proper combination of resonance and focus to achieve the tonal goal. Leo Fender found a great combination with the classic Jazz bass. He typically used very light and resonant alder for the body, giving it a great amount of range from the bass response to the midrange. The necks, being made of denser maple, gave the midrange more focus. Capping the neck with a dense, but open grained rosewood fingerboard added a nice sweet treble to the top end of the tone, but the open grain was less bright than a fingerboard of maple. This made the bass perfect for the types of tone we hear in classic rock, country and blues.
Later as dense ash bodies were introduced with maple fingerboards, the character of the tone was changed. The denser ash added more focus to the low mids and the maple fingerboard added even more treble range to the bass. This gave way to the basses being particularly good for slapping and popping.
Today, with all the various woods available to builders, there are even more possibilities to choose from.
Well, there you have it!
Does anyone else have any thoughts or insight? Share your thoughts in the comments a comment below!
(And thanks Pete!)
Photo taken from our Custom Shop feature on Skjold Design Guitars.