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Topic: Bar science? Why do they differ? |
Al Evans
From: Austin, Texas, USA
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Posted 14 Nov 2018 9:03 am
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Has any scientific investigation been done on why bars sound so different from one another? Given two bars of similar size and mass, both highly polished, one of stainless steel and one of chroms-plated steel, why would they differ in tone and sustain?
I have no problem understanding how a softer material uses up more vibrational energy due to friction, or how a less massive one would be more inclined to use up energy by picking up the vibrations itself.
But given substantially similar mass and hardness, why would there be a difference?
As a dyed-in-the-wool skeptic, I wouldn't have believed it until I experienced it.
--Al Evans _________________ 2018 MSA Legend, 2018 ZumSteel Encore, 2015 Mullen G2, G&L S-500, G&L ASAT, G&L LB-100, Godin A4 Fretless, Kinscherff High Noon |
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Dave Mudgett
From: Central Pennsylvania and Gallatin, Tennessee
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Posted 14 Nov 2018 11:49 am
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I don't know about "science", which to me implies developing theories and then testing those theories with rigorous experiments, adjusting theories, re-testing, and so on, until some type of convergence takes place. That's the kind of "science" I know about, and I don't see a lot of it in the "outer" non-science world. Nor is true science always necessary - art is art, science is science, and they are not necessarily always dependent on each other.
On the other hand, many steel players have a lot of very useful anecdotal experience with bars, strings, and playing parameters and many have formed some well-developed conclusions. And thus, in the days when people on this forum were not afraid of open, frank, and sometimes even heated exchange of ideas about steel guitar, many discussions ensued. A properly crafted search on a decent search engine (e.g., google) will point out many of these, such as
https://steelguitarforum.com/Forum5/HTML/004346.html
https://steelguitarforum.com/Forum15/HTML/013650.html (this is a long and somewhat contentious thread, but there's lots of useful information exchanged if you're willing to read through it)
https://steelguitarforum.com/Forum5/HTML/005275.html
https://steelguitarforum.com/Forum5/HTML/006980.html
https://bb.steelguitarforum.com/viewtopic.php?t=27899
https://bb.steelguitarforum.com/viewtopic.php?t=27899
And there are many more, I'm not going to try to make this exhaustive.
To my mind, there are many issues, which include
1. Bar size (length and effective diameter/width);
2. Bar materials - there are a LOT of possible materials including stainless steel, other steeel, brass, aluminum (or other metals), various types of polymers/plastics, glass, zirconium, and no doubt others I've never heard of;
3. Bar construction - bullet, dobro-style, solid vs. hollowed-out, laminated and/or coated, and so on;
4. Mass;
5. Density;
6. String material and construction;
7. Steel guitar design and construction;
8. Playing style and technique;
and no doubt plenty of others. As long as we're talking bullet-style pedal steel bars, the big issues for me are: 1) Size - I have large hands, and need a bigger bar); and 2) Material - I like fairly dense/high-mass bars for sustain, and prefer BJS chromed or zirc bars because for me they slide better over stainless strings, which is what I tend to use. The latter comes (to me, at least) from Bobbe Seymour, who always argued that same-metal to same-metal contact produces more friction, which I found to be true when I tried it myself. You'll see a lot of this kind of stuff in the threads I linked.
I think one needs to scope any study of this kind of thing quite narrowly to make useful observations and conclusions. That is certainly what useful "scientific" investigation does. |
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Ian Rae
From: Redditch, England
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Posted 14 Nov 2018 2:29 pm
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One parameter Dave doesn't list is coefficient of friction, which I suspect is different between chrome and stainless. There is also the difference between dynamic and static coefficients to consider. How these affect the harmonic content of a vibrating string I have no idea - just an engineer's hunch! _________________ Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Donny Hinson
From: Glen Burnie, Md. U.S.A.
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Posted 14 Nov 2018 3:42 pm
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One factor that hasn't been mentioned is surface finish - there's smooth, and then there's s m o o t h ! That also affects the sound and sustain. But when we say that one bar sounds better, what do we really mean? of course, the acid test for this is to record your playing with several different bars, and then try to tell by just listening as to which sounds best. Differences which then can't be heard on a playback should be considered apocryphal, I believe. And it's also true that stainless steel bars don't feel as good (the same?) when you use stainless steel-wound strings.
In addition, like most things, I personally feel that bar qualities are somewhat simple and basic when you're a beginner, but that needs can increase as the ability of the player increases. The standard argument that "starting out, I want the best there is" is rather unreasonable for a beginner, IMHO.
You don't need a Stradivarius to learn to learn to play violin. |
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Dave Mudgett
From: Central Pennsylvania and Gallatin, Tennessee
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Posted 14 Nov 2018 4:11 pm
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Quote: |
One parameter Dave doesn't list is coefficient of friction ... |
I think of that and some other paramaters as implicitly considered in the combination of bar/string materials and construction. That was Bobbe's point that I referenced - that the COF of like-metal on like-metal is higher. Other relevant and fairly obvious physical properties I didn't list that follow from bar/string materials and construction are hardness and (as Donny points out) smoothness. I have no doubt there are others.
Ed Packard measured vibrational properties of some pedal steels some years ago. I believe he studied the impact of the bar, to some extent, and he was the guy that spearheaded the reissue of the zirconium bar about 10 years ago or thereabouts. There are a bunch of older threads about his studies. |
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