Bass guitars

[GlassBass]

Has anyone Actually tested to see if the body wood of a bass guitar has anything to do with the tone of the instrument? No one seems to be able to give me straight answer, and everything reads like mystical nonsense on builder pages. How can a tiny vibration rally affect 9 pounds of wood, and the pickups work off the strings anyway.

I am starting to think it's all in the neck wood, and pickups. possibly just the pickups and preamp.

[Mike Sulzer]

Has anyone Actually tested to see if the body wood of a bass guitar has anything to do with the tone of the instrument? No one seems to be able to give me straight answer, and everything reads like mystical nonsense on builder pages. How can a tiny vibration rally affect 9 pounds of wood, and the pickups work off the strings anyway.

I am starting to think it's all in the neck wood, and pickups. possibly just the pickups and preamp.

I would agree that the neck is more important. The string is attached into a flexible system; when the string vibrates, the tension on that system varies and it responds by flexing. This flexing has an effect on the vibration of the string since the neck-body flexing stores and absorbs some energy. The body is thicker than the neck, and so bends less, but bend it does.

In fact, the tension on bass strings is quite a bit higher than that on a guitar. Body thickness varies, but on the whole body thickness is not greater than typical for a guitar, and can be less on some instruments. It is expected that the wood of a bass body is more important than that of a guitar.

[Jason Rodgers]

David King is the man to respond to this question, and his recent GAL presentation addressed some of this issue. Neck length and stiffness are big factors, but I recall reading a discussion on the mimf long ago about bridge placement on the whole neck-body system being a major difference between the resulting tone of guitars and basses. Specifically, if you think of the whole instrument - from headstock to butt - like a big marimba bar (super-over-simplification, of course), a guitar bridge is closer to the node of vibration than on a bass guitar. This only affects upper frequencies, I think, but also plays a role in issues like "wolf tones."

[jason lollar]

related http://www.acs.psu.edu/drussell/guitars/guitars-ASA.pdf

[John_H]

related http://www.acs.psu.edu/drussell/guitars/guitars-ASA.pdf

It seems almost what you would expect that a smaller solid body has a higher resonant freq.

"Roving Impact Hammer" I like that.

[Mike Sulzer]

related http://www.acs.psu.edu/drussell/guitars/guitars-ASA.pdf

Thanks Jason, I had lost track of that reference. Notice how important the twisting (torsional mode) is for the body. This is probably even more important for a bass body, which can be thought of as relatively thinner.

[Rick Turner]

A fellow named Dave Woolworth did a really great research project when he was an undergrad on the resonances of bass necks. #1 was, of course, flexture in the string vertical plane; # 2 was flexture parallel to the string plane; and #3...and a very strong one, was the torsional resonance of the neck, and that is greatly affected by the tuners...mass and location.

Body wood (or other materials)? Very important, and the closer to the strings the more important it all is.

[David King]

All basses sound like basses. The lighter-weight ones get played more.

[David Schwab]

Has anyone Actually tested to see if the body wood of a bass guitar has anything to do with the tone of the instrument? No one seems to be able to give me straight answer, and everything reads like mystical nonsense on builder pages. How can a tiny vibration rally affect 9 pounds of wood, and the pickups work off the strings anyway.

I am starting to think it's all in the neck wood, and pickups. possibly just the pickups and preamp.

Have you built any basses? Same is true of guitars, different woods will impart a somewhat different tonality.

Thinking that vibrations are doing it is the wrong way to think. I like to use as a comparison, a heavy solid body guitar, like a Les Paul and a banjo. The solid body guitar doesn't have very much acoustic output. The mass of the body is too great for the energy from the strings to excite. So you get a low acoustic output, and very long sustain. This is because the body is not stealing energy from the strings. Rick Turner had a neat idea at Alembic, where an "inertia block" of brass was placed under the bridge. This helped decouple the strings from the body.

The other extreme is a banjo. Most of the energy from the strings is converted to acoustic sound, as the head vibrates. So you have a loud acoustic output, and very little sustain.

So, somewhere between the two, the body will have an effect on the vibration of the strings, as it absorbs some of the energy. This will be based partially on the resonant frequency of the body, so you end up with comb filtering. Harder, heavier woods will vibrate less, and have a brighter tone. The softer, lighter woods will have a warmer tone. You can hear this on very light woods like basswood, and on hollow bodies.

But I find the neck, especially on a bass since it's fairly long and flexible, will have a more profound effect. And it's all because of losing energy from the strings. I find the stiffer the neck, the brighter and more focused the tone. Scale length matters too.

Pickups have an effect of course, but something like a Rick still sounds like a Rick when you have different pickups in it. It's just the frequencies are filtered differently. Or put humbuckers on a Strat, and Strat pickups on a Les Paul. They don't sound the same.

Here's a good example. I built these two basses back in 1994:



(This photo was when they still had EMGs in them, and the bass on the right is obviously missing an output jack and has a broken string!)

Both basses are made almost exactly the same... they both have cherry bodies (from the same board) and 7-piece maple/purpleheart necks, with two truss rods, graphite bars, and phenolic fretboards. At one time they both had the same bridges and pickups. The only difference is the top woods; zebrawood on the left, and figured maple on the right. The bodies are multi laminated, so there's a 1/4" piece of purpleheart between the top and back.

The bass on the left is noticeably warmer and a bit louder acoustically. The maple topped bass is brighter and tighter sounding. Besides the top woods, the section of cherry board used for the maple bass was highly figured. Denser wood?



So, with the same hardware and pickups they were quite different sounding. So much so, that I put an aluminum bridge on the zebrawood bass to help brighten it up, and when I installed my own pickups, I used brighter sounding pickups.