theshadow2001 said:
Ok I apologize to everyone but I can't let this slide.
Inertia is a bodies resistance to a change in it's state of motion.
All bodies are going to have an inertia. But the value of inertia for that body is going to always be the same as long as it's mass and shape don't change.
Newtons cradle shows the conservation of energy theory which states that energy can't be created or destroyed but only change from one form to another.
Each ball and string has an individual inertia but that does not change or get transfered. What does happpen is the change of energy from one form to another mainly potential to kinetic.
Again I apologise to everyone else for throwing rfuel on the fire.
Anyway all that being said. I wonder how wood effects the production of harmonics by the string. After all isn't it these harmonics the give the bass it's timbre.
To my recollection, there is something called "moving inertia" as well as static inertia, but perhaps inertia is the wrong term. I'm a bassist, not a scientist. Prefer the term vibrational energy? Potential? Whatever you care to call it the energy that is within a vibrating string passes via acoustic and physical coupling to the body and neck, via the bridge and nut. The more rigid the instrument, the less this is a factor. What remains, however, is the fact that the "tone" of the resonant body is what is removed from the overall tone of the string when this energy is transferred.
I am also a producer/engineer, and a car nut. In the other thread I gave an analogy to a Chevy valvespring. Now I'm going to give one to drums (it helps to have knowledge of many things, it's surprising sometimes how much carries over from one thing to another).
When tuning drums, I always tune the lower head either one semitone or so higher or lower. This accomplishes a number of things. First, it keeps you from having to tape the linen closet to the kit (something I abhor), or use gates to control over-ring, and second, it creates this wonderful pitch drop in the decay, almost like the old Simmons electronic drums tried to immitate (but exaggerated wildly).
What happens is, vibrational energy transfers from one head to the other and back contantly (via both acoustic and physical coupling), and as the vibrational energy flows back and forth, a bit is lost "in translation" all the time. This causes the drum to decay much more quickly than if the heads were tuned to the same pitch. In other words, the lower head (not struck) is coerced to vibrate more easily if its pitch matches the top head, but less easily if it differs. Someone who knows how to tune drums can use this to manipulate the drum's decay.
What is interesting is that it still does vibrate, though, even if tuned at a different pitch...BUT, it "costs" energy to do this "translation"...some of the vibrational energy is lost, and the drum decays more quickly, and has less sustain as a result.
When the neck or body of a bass resonates, it does the same thing. Its steals vibrational energy from the string, and the result is less sustain...just as in the case of the drum.
I view this vibrational energy as having "potential" to move things, therefore I called it inertia. It was my understanding that inertia was potential, either the potential to want to remain static, or to continue to move if moving, but I'm just as happy calling it "vibrational energy".
The fact remains that this energy or force can move from one body to another, just as in the case with Newtons Cradle (or as in a bass guitar and its strings)...but that just as the cradle demonstrates, the effect fades quickly as the energy is transferred back and forth. The balls quickly come to rest. One ball would swing alone back and forth for a much greater time. The transfer of energy makes the motion decay more quickly.
This is EXACTLY why a more rigid instrument has more sustain, and a resonant one has less. The sonic "fingerprint" of what the resonances remove (absorb if you will), however, is what gives character to the sound. This is how woods color the tone.