Robert Godin explains the "opening up" of an acoustic

[adorshki]

My poor guitar is broke in in B flat..... where does that leave me? :roll:

Busted flat in Baton Rouge? :wink:

 

[adorshki]

If you find an older guitar that hasn't been played (and assuming that it hasn't suffered any structural damage). the guitar's opening up would proceed as if it was a new guitar built with a 15 year old top. The "opening up" process would start from that point, as would the longer term "aging" process. Kostas

That's what I'd think, from everything I've ever come across here or elsewhere. I'd just hope that it wasn't stored with full string tension for all that time. Althought, if that had had any ill effects it'd probably be pretty evident pretty quickly, in the playability at the very least.

 

[adorshki]

but I don't believe that anyone has ever actually published results of scientific studies documenting those hypothesized ideas as actual fact AND their effect on tone. Most of the so-called results are simply anecdotal, not scientific.

There is that study of what, if anything, made the woods in Stradivarii special but as you say it doesn't proceed to combine the findings with a scientific comparison study of effect on what should correctly be referred to as "timbre". (Not to nit-pick you but just to introduce the more accurate musical term).

I'm not saying that opening up does not happen, but that there is not as yet any hard scientific evidence of what actually happens (or may not happen).
Beyond that, without rigorously controlled recordings of before and after, our human psychoacoustics are extremely unreliable in comparing sounds, especially with time intervals of years between sound samples.

Even though I do believe in the "opening up" phenomenon, I also agree 100% with all those points.
I can remember at least 2 attempts on this forum to simply create a scientifically valid comparison model to analyze the effect of aging of wood and finish on timbre, and one of the apparently insurmountable hurdles IS that NO two pieces of wood will in fact be identical, and therefore it's technically impossible to create the comparison model.
And that's even before attempting define what constitutes "better" or "worse" in terms of any comparison of measurements of things like frquency amplitude and waveform and distortion.
It occurs to me that maybe this means the phenomenon will always have the attraction of "mystery". I kind of like that.

 

[cjd-player]

what should correctly be referred to as "timbre". (Not to nit-pick you but just to introduce the more accurate musical term).

I agree, but its funny that the word "timbre" is rarely used for acoustic guitars (maybe in the classical world, I don't know about that realm). For example, the lower braces on the soundboard of a traditional x-brace pattern are called tone bars; yet technically they effect the timbre of the guitar. You almost always see guitars being discussed with regard to tone or voice. "The tone is in your fingers" "Maple has a bright tone - rosewood has a dark tone - mahogany has a sweet tone", etc.

I guess it's kinda like Leo Fender misnaming his vibrato bar as a tremolo bar, where the error became entrenched in guitar nomenclature.

the more accurate musical term).

Shucks, how many guitarists know anything about music? :mrgreen: :mrgreen:

 

[dreadnut]

cjd, even though I'm no metalurgical engineer, I can appreciate your point. I studied and taught electronics soldering for decades, and I'm always amazed at the total lack of understanding people have regarding the chemistry of soldering, even at the largest electronics manufacturers. Without any real knowledge of what's happening at the molecular level, people postulated theories and experimented until they were blue in the face without ever addressing the real issues. The most recent firm I worked for was a military and aerospace manufacturer, and they didn't have a clue how to produce good solder joints consistently. I lost a contract engineering job once because I insisted upon telling them the truth instead of simply falling in line with the old produce and rework concept. Unfortunately, they've made most of the US controls for ranges, washers and dryers, and refrigerators. Especially maddening when I've had 3 refrigerators and one range crap out over the last ten years. Service techs' analyses on all four of them: "Bad circuit board." Imagine that.

At least with guitars, there is some subjectivity.

 

[kostask]

Cjd:

The "rigorous scientific studies" probably won't ever be produced, for a couple of reasons. First, wood is a very, very non-homogenous material within the same tree, and wood from different trees, even more so. So taking an SEM picture of the wood structure in a soundboard would be valid only for the actual sample of the piece of wood. Second, not many luthiers have. or have access to, SEMs on a regular enough basis, over a long enough time, to be able to create such a body of knowledge.

While Al Carruth may not have the "hard" science based data, his explanations for opening up and aging are one of the few logical and reasoned attempts that ties both of these phenomena together, in a manner that seems to be based in what we know of wood, and how wood changes over time. Besides, his attempt to explain the phenomenon is the only one that isn't based on sprinkling pixie dust and eye of newt around.

If anybody else knows of a logical attempt to explain the opening up and aging phenomenon in guitars, please let me know about it, I'd like to read it, whether it fits in with what Al Carruth has written, or not.

Kostas

P.S. Dreadnut, some day, try to get across to a contract manufacturer (one of the majors in China) that their dendritic growth problem is caused using the improper flux on a board. They will fight tooth and nail, for at least 6 weeks, until they have exhausted some of the most outlandish and hare-brained ideas, before they admit that they used the wrong flux for the solder mask/temperature profile used.

 

[fronobulax]

Point about no two pieces of wood being identical noted, but that does not preclude doing real "science" as cjd et. al. use the term. The key is statistics, which is not always a refuge of a scoundrel. Of course the investment required to develop and perform a statistically significant analysis on guitars "opening up" with age is probably a couple of orders magnitude more than the answer is worth. I'd love to know but I wouldn't ask anyone to spend $10 million over 15 years to get me the answer.

I also have to ask are guitars like wine, in that they almost always get better with age, or do some guitars get better and others not? Someone asked "where are the guitars that don't get better" and it is an insightful question. Are they really the guitars that people don't "bond' with or what?

My hunch, and that is all that it is, is that a well crafted wooden musical instrument is going to get better with age with getting better referring to the way the instrument responds to the player and the "sound" produced. I think that this is true of violin family instruments and will eventually be understood to be true of "modern" guitars.

 

[dreadnut]

Kostas: I've abandoned electronics manufacturing altogether, I decided it is what it is and I can't change it. Music is my last bastion of hope

 

[cjd-player]

... I lost a contract engineering job once because I insisted upon telling them the truth instead of simply falling in line with the old produce and rework concept...

... try to get across to a contract manufacturer (one of the majors in China) that their dendritic growth problem is caused using the improper flux on a board. They will fight tooth and nail, for at least 6 weeks, until they have exhausted some of the most outlandish and hare-brained ideas, before they admit that they used the wrong flux for the solder mask/temperature profile used.

Trying to buck the establishment with real, actual, scientific data can be difficult sometimes. At a prior job we sold tool steel to the U.S. Mint for coining dies. (That was a stretch because they had been using common alloy steel for many years. Only took about 100 years after tool steels were invented for the U.S. Gov to try them for tooling.:roll

Anyway, they had just recently purchased many millions of dollars worth of new CNC grinders to make the coining dies. After numerous failed dies, I did analyses and showed them that they were getting grinding burn and ruining the tool surface. (Like overheating, and turning blue, a wood chisel when sharpening). They essentially told me I was an idiot. Several weeks later after numerous other attempts, even with the old alloy steel, they finally came back with their tail between their legs and admitted I was correct.

People simply don't want the truth if it conflicts with their preconceived ideas.

 

[markus]

(Such as the so-called stretching of guitar strings when you install new ones. But that is a whole separate topic.)

Have you covered this topic on LTG yet?
Markus

 

[davismanLV]

(Such as the so-called stretching of guitar strings when you install new ones. But that is a whole separate topic.)

Have you covered this topic on LTG yet?
Markus

Yes, I'd be interested to hear what this is all about...... Carl?

 

[gilded]

So what about the concept of 'aged wood' as a part of a musical instrument?

 

[dreadnut]

People simply don't want the truth if it conflicts with their preconceived ideas.

Exactly. or as a wise friend once told me "Perceptions, in the eye of the beholder, are every bit as real as reality."

 

[cjd-player]

(Such as the so-called stretching of guitar strings when you install new ones. But that is a whole separate topic.)

Have you covered this topic on LTG yet?
Markus

Yes, I'd be interested to hear what this is all about...... Carl?

Without boring you with the metallurgical details, when you "stretch" the new strings after the install, suffice it to say that the strings do not stretch at all. You are simply seating the ball end at the bridge plate, and tightening the windings on the tuning post. Yes, it needs to be done, but there is no need to uniformly "stretch" the strings all along their lengths. No stretching is involved.

 

[West R Lee]

Hmm, allow me to throw this out there Carl. I'll grant you that string balls seat (find there place), but I believe that strings stretch also. In fact, I've used bolting techniques that actually pull a stud and the nut is then applied hand tight, when the stud is relaxed the desired torque is met. In either case, a large mass of metal is stretched, and these bolts are huge. The studs are stretched with a hydraulic pulling device.

With other bolts, a pin is built within the centerline of the bolt, as the nut is tightened, readings are taken between the bolt end surface and the pin in thousanths with a depth micrometer as the bolt is pulled up around the pin, which is stationary. Once the desired pin depth is met, the bolt is sufficiently stretched. I've also seen many bolts that wouldn't achieve a desired torque as they had been tightened so many times, they were permentantly stretched, or rather, a desired torque might be met, but the fastener would not clamp sufficiently.

Both cases stretch metal dramatically, as I'm talking about studs from 1" to 3" diameter. A guitar string has to stretch. "Stretching" of metal is how torque is achieved. I've used these techniques many times over the past 30 plus years as it is standard practice on some large compressors and turbines, and worked with countless mechanical engineers in doing so. Now, if I take a guitar string, say .011" in diameter, and pull it with a mechanical advantage (a tuner), it has to stretch :? . Now I don't think guitar strings stretch 1/2", but they do stretch slightly.......at least several thousanths. :wink: If I may be so bold. :lol:

West

 

[Dr. Spivey]

Both cases stretch metal dramatically, as I'm talking about studs from 1" to 3" diameter. A guitar string has to stretch. "Stretching" of metal is how torque is achieved. I've used these techniques many times over the past 30 plus years as it is standard practice on some large compressors and turbines, and worked with countless mechanical engineers in doing so. Now, if I take a guitar string, say .011" in diameter, and pull it with a mechanical advantage (a tuner), it has to stretch :? . Now I don't think guitar strings stretch 1/2", but they do stretch slightly.......at least several thousanths. :wink: If I may be so bold. :lol:

West

Yep, even relatively small rod bolts in an engine stretch. Manufacturers give spec's on the amount of allowable stretch, once that is reached the bolt is junk. I too, would think that guitar strings stretch some small amount, although the act of stretching them mainly seats the balls and the wraps on the tuners.

 

[cjd-player]

Hmm, allow me to throw this out there Carl. I'll grant you that string balls seat (find there place), but I believe that strings stretch also. In fact, I've used bolting techniques that actually pull a stud and the nut is then applied hand tight, when the stud is relaxed the desired torque is met. In either case, a large mass of metal is stretched, and these bolts are huge. The studs are stretched with a hydraulic pulling device.

With other bolts, a pin is built within the centerline of the bolt, as the nut is tightened, readings are taken between the bolt end surface and the pin in thousanths with a depth micrometer as the bolt is pulled up around the pin, which is stationary. Once the desired pin depth is met, the bolt is sufficiently stretched. I've also seen many bolts that wouldn't achieve a desired torque as they had been tightened so many times, they were permentantly stretched, or rather, a desired torque might be met, but the fastener would not clamp sufficiently.

Both cases stretch metal dramatically, as I'm talking about studs from 1" to 3" diameter. A guitar string has to stretch. "Stretching" of metal is how torque is achieved. I've used these techniques many times over the past 30 plus years as it is standard practice on some large compressors and turbines, and worked with countless mechanical engineers in doing so. Now, if I take a guitar string, say .011" in diameter, and pull it with a mechanical advantage (a tuner), it has to stretch :? . Now I don't think guitar strings stretch 1/2", but they do stretch slightly.......at least several thousandths. :wink: If I may be so bold. :lol:

West

You're talking about elastic deformation in all of those cases. When you take the tension off, the part will return back to its original length. The tension on a guitar string at normal pitch will take the steel into the elastic range, but does not take the steel into the plastic deformation range (not even the slight tension increase of "stretching" by hand). If you were to tension it into the plastic deformation range (permanent length change) you would ruin the string. The only time a string would go into the plastic deformation range is a second or two before you broke it if you tuned it so high that it broke.

So yes, you may be marginally lengthening the string as you pull on a new string install, but it returns right back to its original length as soon as you let go. In, fact, it's not lengthening at all during the pull until the ball end is set and the windings on the post are tight. But then it stays at pitch and no further pulling is needed. You didn't "stretch" the string to make it stay at pitch, you just secured it to the bridge and tuner post.

To say that you need to stretch a new steel string for it to stay at pitch is analogous to saying that you need to stretch a new rubber band a couple of times before it will work to hold a bunch of pencils together. It makes no sense at all. Pulling on a string to fully secure it to the guitar does make sense.

 

[Dr. Spivey]

That makes sense, Carl.

 

[dreadnut]

Ah! As Daffy Duck would say: "Pronoun problems!"