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Topic: Tone and Sustain in Construction |
Gary Cosden
From:
Florida, USA
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Posted 8 Mar 2008 5:28 am |
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I think this should be a dedicated topic of it’s own. Here’s a recent post from a related topic by Jim Sliff:
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It's the player mainly.
Sorry, I disagree, and so does most of the luthiery industry.
The player matters *least* when it comes to sustain. It's a function of the physics of the instrument. Right hand has zero to do with it (except for the obvious "variable" that is irrelevant to testing, which is strength of attack. Sustain testing is all based on equal starting vibration energy) and bar pressure on as far as "too loose" would cause buzzing and loss of vibration.
Sustain has been studied to great lengths (and expense) in the 6-string world, and the following are *some* of the findings:
1. As stated, the player isn't part of the equation
2. Pickup height is critical, and there's a significant relation ship between height and magnet strength - the more pull, the further the pickup needs to be from the strings, but there's a "sweet spot" - if you get TOO far you lose:
3. Input signal strength. Has to be strong enough to drive the electronics that follow.
4. Construction. There are two theories, both considered correct and diametrically opposed in approach:
A. The platform much be rock-solid to allow strings too vibrate with no lost energy through platform vibration; if string energy is lost through the platform picking it up, vibration of the string drops off rapidly.
B. The platform must vibrate sympathetically to the strings. This is the "acoustic theory" science thought - the right combination of parts (wood, especially) will vibrate sympathetically with the strings and create a "chain" of vibration feedback, if you will, increasing the time period of the vibration. It's dependent on a ton of factors in construction and is what most guitar makers base their construction methods on, and includes everything from body construction to the weight of tuners.
5. Kind of a subset of "A." above, elimination of moving parts. Simple examples - bar-type bridges have far better sustain than roller-types made of similar materials with similar mass; the same would be true of nuts.
6. Amplification (if any - obviously only applies to electric or mic'd instruments) - very complicated, but basically it comes down to transparent, controlled feedback - the sound coming out of the amp continues to activate string vibration at certain harmonic levels.
This is a very simplified version of some of the major factors, so no flames, please. I'm just trying to present some of the proven factors luthiers have discovered and massaged over time. Obviously, many of these things affect the tone of the instrument as well, another area the player is a small part of (with attack - angle, strength, and distance from bridge) being the only player-dependent factors (and that only slightly manipulate the natural tone of an instrument).
This is an excellent and comprehensive list but I am mostly interested in 4A & 4B.
I have always been a big believer in 4A: it is where the body or cabinet does not resonate that matters most. Resonance by the body consumes the energy of the vibrating string and thereby limits sustain.
I have always believed that 4B is just a carry over from “acoustic” instrument theory and basically just doesn’t wash for solid body electric instruments.
I recently had a conversation about this with a forum member who shall remain nameless (if he reads this and wants to chime in I’m sure he will) but I will say that his opinion is about as well respected and qualified as it gets. He has convinced me that there really is something, at least, going on in the general area of 4B, perhaps directly related to the “resonant frequency” of the cabinet. According to him making the body of the guitar thicker and heavier can actually result in a loss of tone. (I am assuming a direct link between sustain and tone with regard to construction by the way).
At this point I have a lot of questions and no answers:
Is it really as simple as building a cabinet with a certain resonant frequency to give a great tone with lots of sustain? If so, how would you go about determining the resonant frequency of a given cabinet so it could be reproduced using, say, different materials and or dimensions. Could you, for example, end up with a keyless guitar made from carbon fiber that in terms of tone and sustain was virtually identical to a maple body push-pull?
What, for that matter, is the relationship between resonant frequency and tone /sustain in the first place? The only thinking on this I have ever come across from the luthier’s world is that the RF must be significantly lower than the lowest fundamental note the guitar can
produce. If the above theory has any merit if the RF is too low tone/sustain will be reduced. If you knew the RF of an Emmons push-pull would you then know the “secret sweet spot” of tone and sustain?
I have also heard talk about the idea that resonance in the body can actually “feedback” to the strings thereby yielding greater tone/sustain. I say any resonance that could feed back to the string would have to be sympathetic resonance which would result in less tone and sustain so this particular idea to me at least doesn’t wash. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 8 Mar 2008 10:42 am
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Just last week, I visited a guitar factory. Outside, there were dumpsters chock full of brand new guitars...hundreds, no thousands of 'em!
The factory rep told me..."They're all going to the landfill, all those are guitars with less than perfect sustain, or no sustain. Nobody will buy them. No one wants them. We can't even give them away."
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Bill Hatcher
From:
Atlanta Ga. USA
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Posted 8 Mar 2008 11:01 am Re: Tone and Sustain in Construction
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| Gary Cosden wrote: |
I think this should be a dedicated topic of it’s own. Here’s a recent post from a related topic by Jim Sliff:
Quote:
It's the player mainly.
Sorry, I disagree, and so does most of the luthiery industry.
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I have built 30+ electric guitars from raw lumber not screwdriver built parts guitars. I guess that puts in in "most of the luthiery industry" even if on a small custom scale.
The player is the determining factor in how any instrument sounds. You can take a guitar that has great sustain and tone and if the player has a poor pick attack or poor left hand placement or incorrect string guages put on etc. the guitar will not reach it's full potential for sustain OR tone.
The guitar without the player is nothing. The interaction of the player with the guitar is everything. |
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Richard Damron
From:
Gallatin, Tennessee, USA (deceased)
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Posted 8 Mar 2008 11:21 am
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Gary -
In essence, I chose to address the same issue as you but in the "Sustain" post by Glyn Bone. Since you have better insight on this subject than most I would refer you to the work done by Ed Packard. I assume that you are unfamiliar with this work so - in brief - he made spectral and sustain measurements on over 30 different instruments. He has readily admitted to me in an e-mail that there were some aspects of the measurement technique that were lacking. Nonetheless, the data are at least reasonably valid and the difference between instruments quite striking. Note that his data concerned only INHERENT spectral and sustain characteristics of COMPLETED instruments. He has not, to my knowledge, attempted bare-bones acoustic measurements on cabinets, for example. As I have stated elsewhere, I would welcome such research.
Until such time as someone does a comprehensive study of the instrument, we are left to ponder the real reasons for differences in tone and sustain.
Since you have your head into acoustics, try Googling "Catgut Acoustical Society" which will refer you to the volume of work done by Carleen Hutchins et al on the acoustic properties of violins. I had the pleasure of meeting Carleen and others some 40 years ago and remain interested in the subject to this day.
Stay the course. Conjecture abounds. Your head is but one of only a few which is attempting to zero in on the real determinants of tone and sustain within the instrument.
Respectfully,
Richard |
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Gary Cosden
From:
Florida, USA
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Posted 9 Mar 2008 8:10 am
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Donny - that sounds like a very strange thing to behold indeed. I guess if you really can't get rid of them you do end up throwing them away!
Bill - when I reread my own original post I realize that I failed to make clear why I thought this deserved it's own topic so I apologize. I agree with every word you said but I wanted to narrow the focus of this discussion to the impact that the design and construction of the cabinet has on tone and sustain. You will never get an argument from me on the role that the player has in this equation.
Richard - I am indeed aware of Ed Pakard's work for which he deserves a great deal of credit and appreciation and as you point out it does not (as far as I am aware) address the question of the RF of the cabinet. Please correct me if I am wrong. Thanks for the suggestion and if you want a bit of an interesting one yourself try googling "compensating nut" sometime and see where that leads you. If you are anything like me the results will intrigue you. It makes me wonder about compensating bridge arrangements and if/how they would or should be applied to the pedal steel guitar - but that's a whole new topic. |
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Jim Sliff
From:
Lawndale California, USA
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Posted 9 Mar 2008 7:54 pm
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Bill - while that's true to a point, we've been discussing acoustic theory in the other threads and how construction and related factors affect the instrument...not the player+instrument. That's a different subject, and "4A + 4B" above exist no matter whether Tony Rice or an orangutan is playing the guitar. If either of them (by accident) creates the same string vibration and then doesn't move, they're out of the equation and one of the two tone/sustain lines of thought becomes the guiding factor.
It's like claiming two different players will get different tones out of a steel picking one open note at the same attack angle at the same distance from the bridge with the same pick using the same force. As somebody once said, tone is in the hands...
Donny - obviously this subject bores you, since you're posting sarcastic nonsense in every tone or sustain related thread. Why not leave the discussions to those interested in the subject?
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No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Bob Hoffnar
From:
Austin, Tx
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Posted 9 Mar 2008 9:51 pm
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I am not sure how this relates to the bit about guitar construction but I have found that the pedal steels that have the most sustain and overtone stability actually seem to vibrate as a whole unit. You can strum the neck without an amp and feel the front legs vibrating. I have switched legs to a lighter aluminium leg and noticed a marked difference in sustain and clarity. I'm not sure that would be the case with all steels but it sure was with my Franklin. It seems that the feel and skill of the builder has quite a bit to do with it.
I'm really impressed by how much better steel guitars are getting every year. I'll check out a steel like a Carter, MSA and a ZUM one year and have little complaints I keep to myself about them. Stuff like overtone clarity, mid range strength, balanced tone and output all over the neck. The next year I'll come back and the problems are gone. The year after that I play them and not only are the problems gone but the sound just blossoms out.
I build pickups and deal with them constantly these days. I'm not sure if they have much to do with sustain though. There is so much tension on steel guitar strings I don't think the magnetic force from pickups pulls on them very much at all.
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Bob |
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