What component of the guitar contributes the most to tone?

[Dave Mudgett]

Ed - of course, I agree that the spectrum analyzer approach can be used to analyze any of this. I also agree that the open-string spectral analysis is a good benchmark - I think I argued that line in earlier threads.

My real point was that I would take exception if someone insisted that considering external things - like the bar, or using listeners to try to understand how these tonal differences are perceived - as off-topic for a discussion like this. BTW - I didn't hear Ed say this, just that his particular interest was in the baseline spectrum analysis. I don't think we are in disagreement at all here.

To me and I imagine many others, it's perceived tone in a practical playing situation that matters most. This does not render irrelevant any objective baseline frequency response analysis. But people play this thing with a bar - yes, there is lots of diversity in left-hand termination devices, but it's part of the thing and can be controlled in experiments. Similarly, people are the ones who actually listen to PSG. I do think it's well established that people hear things differently, and that may well be hard to control and account for differences. But I don't think that, in itself, renders the perceptual issue irrelevant or off-topic.

I certainly agree with Ed that trying different types of left-hand termination is a useful experiment, and says a lot about what matters. I have tried a bunch of different steel bars, dobro bars, steel, brass, glass, and plastic slides, Coricidian bottles, sockets, and other assorted junk to try to get different sounds. But I think one could establish a bar standard, and now study the effect of various design changes on tone, using FSA or listeners.

[Ken Byng]

There are some wonderful posts here with some very interesting analysis. One thing for sure - we could keep this post going for another hundred years and there still wouldn't be universal agreement. I suppose we all have benchmark tone in our head that we aspire to achieve one way or another. My take on the subject is that the tone of a steel guitar is the sum of its parts. I don't believe that the pickup is the major factor. Put a great pickup on a poor sounding guitar and the end product would still be poor.

[Donny Hinson]

Ed, I'm still trying to understand...pardon my repeated questions.

You said...

1. When you pick (excite) the string you impart energy to it.
2. Assuming no feedback from sound in the room, there will be no other source of energy imparted to it.

And then you said...

The materials in the body/mechanism ARE part of a feedback loop built into the PSG, therefore they effect the string vibration. In one sense, they may be found to contribute positive feedback to the strings at some frequencies…this would ADD (enhance) to the strings vibrations at those particular frequencies.

These two premises seem to contradict each other. Would you mind, please, elaborating a little about that?

[Robert Leaman]

Not withstanding all the erudite suggestions and opinions that are posted previously to my reply, the answer to the question is patently obvious.

What contributes more to the steel guitar's tone?

The major contributor is the string set since without a string set, there is no tone.

[Dave Mudgett]

Robert - I also think the strings are important, and one must obviously have strings on the guitar to play it, unless one wants to use it as a drum, heaven forbid.

But the question was, from the original post: "If there was one thing to change to affect the inherent tone of guitar, what would it be?" You aren't really saying that it's obvious that changing the brand or type of string is the most important change one could make to the tone, are you?

Donny - I'm not Ed, but this is the basic mechanics and engineering, as I see it:

1. One definitely does impart vibrational energy to the string by picking it, which can now transfer back and forth to other components of the instrument. Those components can store that energy, dissipate it, or transfer it somewhere else, including back to the strings. A steel guitar is a distributed mechanical system, so this transferance behavior can be very complex indeed.

2. The steel + string system, by itself, is passive - in other words, it can't add net energy. So any energy dissipated in any component is a net energy sink, and overall vibrational energy decreases until additional energy is imparted to the string.

3. None of this negates the fact that there may be feedback mechanisms which transfer energy back to the strings from other components. Again, such a system is strictly dissipative, and the total vibrational energy monotonically decreases unless re-excited somehow. But temporally, the energy in a given component may increase or decrease - the tradeoff is that if it increases in one part, it must decrease in other parts to a net sum of the total vibrational energy remaining.

4. From a frequency response point of view, energy transfer from one component to another involves adding certain vibrational frequencies from the source to those of the receiving component. A critical point which is sometimes overlooked when explaining behavior in frequency response terms is that there are two components of frequency response - the amplitude and phase responses. When one talks about adding two signals, the phase relation between them is extremely critical. Some frequencies may combine additively while others may combine subtractively, depending on this phase relationship. This is yet another wrinkle which can add significant complexity to all this energy transfer.

5. This is all even further complicated on a steel guitar by the presence of the bar, which can be, in principle, constantly manipulated to add energy to the string without picking it again.

6. All of this is without any positive acoustic feedback from the environment, picked back up by the guitar itself or a microphonic pickup. That is yet another possible net energy source which can keep the complete system from being strictly dissipative.

To me, all these "other" relationships and energy sources are a huge part of what, to me, distinguish the pedal steel guitar from other plucked stringed instruments, and why I think that, if set up and manipulated properly, it's possible to treat it in some ways as a "sustain instrument" like a Hammond B-3 organ or a bowed instrument.

At least, that's the way I see this.

[ed packard]

DD...I prefer to give data, ways of getting data, and possible approaches to problems...I prefer to leave conclusions derived from running the experiment or analyzing the data to the observer; they may see something that I missed.

However, since you asked: the Drill Bit experiment gives insight into tone vs. bar size, using a small bar/rod as a bridge, why there is a difference between the tone of the small rod by itself, and the small rod backed up by a larger piece (block), and other assorted such things. I use a small rod as the bridge on the BEAST. This experiment showed that I could do that without problem...so I did.

Donny H...Dave M...great answer...we have had a number of SUPER dissertations in this thread!

Let me try to put it very simply in non technical terms:
If we have a system in which the energy can only become less with time from a value of ...say 10 to 0, there is no ADD above 10 available, BUT it is possible to ADD say an energy level of 1 or 2 to the decaying energy level at say 7 or 5 etc. You can have feedback (thru the body/mechanism) that by phase may either ADD or SUBTRACT to the decaying original, but never cause it to exceed the original 10. Kinda like adding $2 to a decaying $100 checking account. This is not true if the system has a gain of greater than one.

RE the speed of sound in a material (medium)...The velocity of sound varies with the material properties of the medium. This leads to a horse-race between the wave velocity in the steel string, and the wave velocity in the mechanism/body. When they meet they either reinforce each other or ten to cancel each other. By how much depends upon the sonic impedance's involved. The sonic impedance's are set by the materials involved, and there shape and contact. One standard test for this is to take a SQ IN of the materials in question, press them together, induce and measure a spectrum (range of frequencies) into one, then measure the amount transferred to the second. This gives the materials ability (relative) to transfer the spectrum.

Now if the contact area of the test piece (the one of interest)is made smaller, the transfer function will change.

This is an image of string to bar transfer, string to changer finger transfer, string to nut transfer, mechanism to body transfer, etc. Phase shift may be measured in such a way also.

What is "good", and what is "bad"? If you want maximum mechanism body effect, make low sonic impedance's at the material interfaces....if you want minimum mechanism body effect, make maximum sonic impedance's at the interfaces. Do this with material choices, grain direction choices, contact area choices, and to some extent scale length, and total string length choices.

Sonic transfer along and across wood grains are different in most woods.

die board is not direction preferential as the grains go in both directions (along and across).

Aluminum is more predictable.

Carbon fiber depends upon which way the fibers lie = manufacturing process.

Cliff Cane...see what you started? The exact specific "item" of change in your opening question may well be based upon the brand of instrument you have. These days, as has been mentioned, there seems to be several defacto standards for PSG construction.

The most idolized by the traditionalist seems to be the rock maple with keyhead, V grooved roller nut, and about 3/4" dia changer fingers, mostly of soft aluminum, or sometimes stainless steel.

Then they go all the way to aluminum bodies with Keyless (a variety of)...and then, of course, there is the carbon fiber body.

[Dennis Schell]

Not withstanding all the erudite suggestions and opinions that are posted previously to my reply, the answer to the question is patently obvious.

What contributes more to the steel guitar's tone?

The major contributor is the string set since without a string set, there is no tone.

I kinda agree, the string and the "touch" are 90% of the sound....

JMO

Dennis

[Herb Steiner]

The greatest determinant of how a guitar sounds is the nut behind the rear apron, and how tight it is.

[Ray Riley]

It is blatantly apparent why you did not receive the correct answer to your question, Cliff. You asked, is it "weight, body , pick-up, strings, mass(same as weight)." How did you expect these fellas to answer when "color" as in""""""""""""""""""" Black""""""""""""""""""" is the most logical answer to your question. Ask Bobby Seymour, cause I think he is taking Singing lesson. Can't prove it though ,cause I ain't heard him sing. I know this won't help,will it? Ray

[Ken Byng]

The greatest determinant of how a guitar sounds is the nut behind the rear apron, and how tight it is.

Herb - I resemble that remark!!!

[Jeff Bradshaw]

Herb, Your "Nut Behind The Rear Apron" post has brought a great big smile to my face!!!! .jeff