A Little Discovery

[fryovanni]

I see in your drawing you have not only changed your angle to a slighter one at the bridge, but you have also added another break point with a strong break angle just before the ferrules.

...actually --I think-- I replaced one sharp break at the ferrules with a slightly less sharp break over the rosewood bar and a very slight break at the ferrules.

So we've got lots of possibilities here... I need to re-read that thread of yours.

Then there's the X factor - a hunk of rosewood creating another vibration transmission point. Mucks it up for science, but great for playing.

(I can hear Perry's eyes rolling all the way from Down Under). :D

Yep, I didn't really look close at the ferrule. One way or the other we see the effects and it seems worth looking into further to be sure we understand it. You know things like using locking nuts, different break angles, longer string lengths and what have you are certainly a factor in playability and sound. I would hazard a guess that these things have a much more direct impact on sound than species of wood we use. It is kinda odd how much attension is given to choice of wood to micro manage "tone" when so little attension is given to strings(I am refering to most discussions on the board). Every last one of us knows how much of a change in sustain, tone and what not changing old strings for new will make(not to mention different gauges). That should really clue us in to pay close attension to what we do with strings on our guitars. Maybe strings are just not interesting enough?

and then.... The X factor. How is the hunk of Rosewood going to alter the way the string vibrates. Arghhh... If I can't figure out the simple stuff. You know I am not going to be able to nail down something as really complex as that(there is the honest answer). Rosewoods and other oily high density woods have a tendancy to "add warmth to the tone"(there is the "tone wood" responce).

What really counts is your guitar is sounding the way you want it to , and that is what counts.

Peace,Rich

[mikhailgtrski]

What really counts is your guitar is sounding the way you want it to, and that is what counts.

Exactly, and whether it was one change or all of them working together, it's a definite improvement. But I really would like to understand the physics someday.

Of course, last night I picked it up and found that the overtone on the G really didn't go away, in fact it seems worse now... what was I listening to? A little chewing gum should take care of it.

[badsnap]

Good day gentlemen,

Rich, I was one of the participants in that thread you are referring to. I too actually did some experimenting and I remember most of the results.

Everything Rich has previously posted was determined as a factor...especially the change in string length. What was gleaned from that information is that the string tension is constant over the entire length of the string but ipso facto, will change in between the bridge and nut. So, if I increase the length of the string but do not change the scale length, I am in effect changing the tension of the string between the nut and bridge. This is why the strings have a losser feel. Same pitch, same over all tension, but slightly different tension in the playing area.

Looking at the after drawing you have decreased one angle but added a very severe angle between the bar (added piece) and the ferrules (or body, if you like). It is this angle that is absorbing the tension (very high tension on that portion of the string), leaving a looser feel for the rest of the string.

Peace...Rog

[mikhailgtrski]

So, if I increase the length of the string but do not change the scale length, I am in effect changing the tension of the string between the nut and bridge. This is why the strings have a looser feel. Same pitch, same over all tension, but slightly different tension in the playing area.

Looking at the after drawing you have decreased one angle but added a very severe angle between the bar (added piece) and the ferrules (or body, if you like). It is this angle that is absorbing the tension (very high tension on that portion of the string), leaving a looser feel for the rest of the string.

Thanks, I'd always (incorrectly) assumed that the tension between the nut and saddle remains constant for a given string gauge and pitch.

As far as adding a severe angle - before it had a more severe break at the ferrules, going into the body. Now it has a less severe, more rounded break across the rosewood bar, and hardly any break at the ferrules.

Now I've gotta finish the nut - I did a quicky job on the slots, just to get it going, and a couple of the strings bind a bit...

[badsnap]

I will always be the first to say that anything I say or do could be wrong. I believe I am correct, but if anyone has a differing opinion and or facts...please set me straight. At any rate, it all boils down to overall string length. That is the key component.

Peace...Rog

[rhoads56]

Thanks, I'd always (incorrectly) assumed that the tension between the nut and saddle remained constant for a given string gauge and pitch.

Regardless of what a string is doing behind the bridge or nut, the nut to saddle section (playing area) will be a certain pitch, for a certain size scale length, and certain gauge string. If it FEELS looser, or easier to play/fret, that is because of what is happening AT or BEHIND the nut, and AT or BEHIND the bridge. That could be a variety of factors, including break angles, friction, and string length.

The tension of a string tuned to the pitch of an open note, for a given scale length, and a fixed string gauge will be the same, ALWAYS. If there is a mile of 'dead' string length behind the bridge, and a near zero friction nut and bridge saddle, you will need to either: raise the action, or increase the intonated scale length, to achieve correct intonation at the 12th. It FEELS smoother, or easier to play, because when you fret, or bend a string, you and spreading that increase of tension over a longer OVERALL string length (nut to saddle playing area, plus nut to tuner, plus one mile of saddle to string anchor, assuming low friction at nut and saddle).

Lowering the break angle increases the strings ability to transfer vibration to the dead string length, past the nut/saddle. It also lowers the fiction at the nut or saddle, making the dead string length more able to stretch with the playing area of the string, when bending or fretting.

Increasing break angle increases the bridges ability to transfer vibrations directly to the top, regardless of electric or acoustic. That may or may not be a good thing, depending on the instrument, the bridges composition, etc. Increasing break angle also does at least one other thing to a string, especially the larger diameter strings, which will generally impede the strings sustain. This fixes itself over time, at the expense of tuning stability, generally. Research.

[fryovanni]

Good day gentlemen,

Rich, I was one of the participants in that thread you are referring to. I too actually did some experimenting and I remember most of the results.

Everything Rich has previously posted was determined as a factor...especially the change in string length. What was gleaned from that information is that the string tension is constant over the entire length of the string but ipso facto, will change in between the bridge and nut. So, if I increase the length of the string but do not change the scale length, I am in effect changing the tension of the string between the nut and bridge. This is why the strings have a losser feel. Same pitch, same over all tension, but slightly different tension in the playing area.

Looking at the after drawing you have decreased one angle but added a very severe angle between the bar (added piece) and the ferrules (or body, if you like). It is this angle that is absorbing the tension (very high tension on that portion of the string), leaving a looser feel for the rest of the string.

Peace...Rog

Hey Rog,

If I am understanding you correctly. You are saying that we determined the tension in the string is constant. However because of this the tension between the bridge and nut will change? I must not be understanding what you are saying because the tension required to bring a string to pitch between the bridge and nut(scale length) is not going to change unless you change the string itself(make it heavier or lighter).

I believe elasticity is going to relate directly to actual length of the string(was that what you said and I just didn't catch your meaning?).

I ran across this little write up by Ian Noyce-click. It seems that he did a little low tech testing as we were doing, and added a little info on elasticity of strings(from normal string tension, to limits of elasticity on to ultimate strength). I am kinda intrigued by the fact that strings elasticity is not linear. I wonder if a string may actually have modified elasticity(pushing it closer to the limit of elasticity in areas with strong break angles) along its length, and in a sense decreasing compliance. Just thought I would bounce the idea off you.

Peace,Rich

Edit; Sorry for being redundant. I was typing really slow and after I posted you guys had a whole conversation going.

Edited April 11, 2007 by fryovanni

[mikhailgtrski]

Regardless of what a string is doing behind the bridge or nut, the nut to saddle section (playing area) will be a certain pitch, for a certain size scale length, and certain gauge string.

Thanks, Perry! I'll revert to my previous understanding...

It does makes sense that, as you mentioned, a reduced break angle might cause an increase in the sympathetic vibrations behind the bridge. David Myka told me he's never had that issue with his guitars, so I'll have to figure out what I'm doing differently.

[rhoads56]

Sympathetic vibrations can be caused by many things (ive even seen nut to tuner ringing, with a floyd nut). From my research, the most 'toney' neck construction (to my ears, those that assisted me, and those that have used those guitars for recording), also had the longest sustain (clue: dont confuse sustain with strength). UNFORTUNATELY, it also enhanced sympathetic vibrations, to a point where it became a problem for recording musicians. EG: the neck was so vibrant, it forced the dead areas of string to ring like a harp. The sympathetic vibrations only really occour when the playing STOPS though (with that particular style neck construction). Im still working on deleting that 'feature' from that style of neck construction. If i can work that out, WATCH OUT!

[tirapop]

Mikhail, you might try putting "saddles" of different materials on top of your rosewood stopbar. Some brass and maybe plastic rod of the same diameter would give you an idea of how sensitive the sound and feel are to stopbar material.

Rich, as far as the non-linear elasticity near yield (which is the definition of yield, something plastically deforming), it would have a negligible affect on the overall string stiffness. When the string bends over a sharp corner, the part of the string on the outside of the curve will yield, not the entire thickness of the string. For the entire string to yield, the string tension would have to be very close to yield. Noyce's picture shows string tension is about half of yield. A bent string and the high friction forces with large break angles would make the string act as though it were fixed at that point.

[Cameroo]

I have been going over this thread for about an hour now trying to make some sence of it (Ya, I know what you're thinking... Get a life!) The thing that I couldn't wrap my head around was this:

Everything Rich has previously posted was determined as a factor...especially the change in string length. What was gleaned from that information is that the string tension is constant over the entire length of the string but ipso facto, will change in between the bridge and nut. So, if I increase the length of the string but do not change the scale length, I am in effect changing the tension of the string between the nut and bridge. This is why the strings have a losser feel. Same pitch, same over all tension, but slightly different tension in the playing area.

Looking at the after drawing you have decreased one angle but added a very severe angle between the bar (added piece) and the ferrules (or body, if you like). It is this angle that is absorbing the tension (very high tension on that portion of the string), leaving a looser feel for the rest of the string.

Peace...Rog

At first, I thought this was a bunch of gibberish and contradictions (no offence), but after much pondering, I think I know what you were trying to get across. This is how I interpret that (I'm gonna throw in some random numbers, just cuz that helps me explain it):

Say you have a scale length of 25 inches, and another 3 inches of string from the saddle to the body/ferrules. With a very sharp break angle on the saddle, there is a lot of friction at that point. When you strech the string (by fretting or bending, etc.) you effectively only have 25 inches of string to stretch and absorb the increased tension (ignoring the string behind the nut).

Now, if you reduce the break angle across the saddle, this will obviously lower the friction at that point. For the sake of argument, let's say it's eliminated. This effectively gives you another 3 inches of string to "absorb" the increase in tension from fretting/bending the string. In my mind, this would have the biggest impact on the strings feeling "looser".

So what Rich said about having to bend the string farther to get the same pitch (with less break angle on the saddle) makes sence, because there is more string to stretch.

So thanks Rog, for making me think!! Your explaination, as confusing as it was to me, was probably the best one!

Cam

[mikhailgtrski]

It does have some sympathetic vibration going on behind the nut as well (the headstock is similar to the PRS configuration) but it's not bad, and doesn't really show up at the amp. I played it again tonight through the amp, and the issue at the saddle end doesn't seem to be a problem either.

Funny, I was considering a different bridge pickup to try to dial out some of the harshness and overly tight low end I was hearing.

Turns out it wasn't an electronics problem after all.

[ToddW]

Hey, Newbie here, but I've read through this and have to comment. Rog/Badsnap mentioned changing the tension between the nut and bridge but not changing the pitch. I don't want to create an argument, but unless the sting was changed, if the speaking length is the same, that isn't the case. I don't know who Perry is, but Rhodes56 was correct and I liked that post.

For any stringed instrument, the speaking length of the string is what you are tuning. On an electric guitar, the transverse vibrations are the only ones the PUPs will amplify, and that speaking length is from nut to bridge (you hope).

However, the strings also have a longitudinal mode. Remember, their length changes as they vibrate. The speaking length of this longitudinal mode does not always terminate at the bridge and the nut. It will be transmitted to the guitar body, and will likely be more obvious when you are not amplified because when you only amplify transverse modes, you make the LM mode smaller in proportion. I suspect the magnitude of the LM that can go from string LM to body, and then create a TM that the PUPs sense, is very small.

If some of the overtones you don't like or feel are changed, when the bridge to nut scale is unchanged, it is quite possible they are LM's. Changing the guage of an unwound string will alter the LMs. For wound strings the LM will be related to core/winding ratios, so you may not need to change gauge, but simply the brand of strings. Jim Ellis of the PTG (piano technicians guild) wrote a nice book on LM's, and you may be able to find some stuff by searching for Longitudinal modes and strings. There are some articles I've read from MIT so add that too if you like.

Anyway, for TMs, changing the tension will change the pitch. It will have less of an effect on the LM IIRC, so one way to check this is to detune the string slightly and see if the overtones stay on pitch. Often LM's are out of tune with the TM, and if they are close to an odd partial, the detuned string might sound better. You leave the LM on pitch and move the TM partials away from it so they don't beat.

If the issue is/was a longitudinal mode, you have different options on trying to modify it.

Regards and good luck,

Todd

[mikhailgtrski]

Rog/Badsnap mentioned changing the tension between the nut and bridge but not changing the pitch. I don't want to create an argument, but unless the sting was changed, if the speaking length is the same, that isn't the case. I don't know who Perry is, but Rhodes56 was correct and I liked that post.

Thanks, yes, Perry aka rhoads56 corrected that mis-statement... he is one of the "sages" around here.

To muddy the waters even more... my son informed me that he restrung it with a .011 - .048 (Power Slinky) set when he borrowed it recently. I normally use a .010 - .052 (LTHB) set.

[ToddW]

... he is one of the "sages" around here.

Good to know. Thanks, and apologies to Perry for not realizing which post was his. My post wasn't placed so much to correct that as to point out that the back length does count in certain modes. Also, after finishing, I realized there's another point.

On thing designers of pianos learned was that that the back length of a string is important, as is it's angle. Too short a backscale can limit bridge motion. On a hollow body guitar, changing the backscale angle might alter the spectrum. Not sure if it would matter on a solidbody electric. Either way, the lower angle of the string over the bridge could alter the longitudinal mode speaking length slightly. The bridge may have been the termination before he modification. Now the termination for LM's may be at the inserted piece.

If you put the open strings recording on a spectral analyzer, you might be able to see what is going on. The only reason I've learned about this stuff is because my rather expensive piano has a LM near the 13th partial that I don't like and it's getting some new strings to fix that problem.

Todd

Edited April 12, 2007 by ToddW

[fryovanni]

Mikhail, you might try putting "saddles" of different materials on top of your rosewood stopbar. Some brass and maybe plastic rod of the same diameter would give you an idea of how sensitive the sound and feel are to stopbar material.

Rich, as far as the non-linear elasticity near yield (which is the definition of yield, something plastically deforming), it would have a negligible affect on the overall string stiffness. When the string bends over a sharp corner, the part of the string on the outside of the curve will yield, not the entire thickness of the string. For the entire string to yield, the string tension would have to be very close to yield. Noyce's picture shows string tension is about half of yield. A bent string and the high friction forces with large break angles would make the string act as though it were fixed at that point.

Tpop, I was not trying to say that the entire length of string will be stressed. I was just saying that it if stress is added elasticity will be decreased(the string is being pushed closer to its elastic limit) in that area specifically. With a strong bend a string does not yeild on a dime so to speak. It archs, and that arch does fall at the nut or bridge end of the scale length. To confirm this in my mind I looked to two things. 1- I physically saw the string arching(which I never really thought about before). 2-I took a string and tightened it till it snapped, and it did in fact snap at the point at which it was breaking over. The second confirmed for me that the string must be pushed closer to it's limit of elasticity at that point(driving it to ultimate strength first). So that is where I was coming from. If I am off in my thinking let me know what your thoughts are.

This then brings me to my next issue. If I am right in my thinking what would this potentially do to the way a string vibrates? First I thought about what we look for in a good string. We want a string to be supple. If a string is not supple it takes more energy to get it set it in motion,and it will not continue to move as long. We also want the strings to be similar in length and tension, yet be able to be tuned appropriately. That leads us to the wound round string(mass is added by winding, and wound material allows the string to remain flexable as opposed to using a larger solid string). The combination of greater mass and flexability also creates a more efficient string(louder). Looking at those things alone. You would be able to say that a decrease in the strings flexability will decrease its efficiency(how much, would totally depend on how significant the loss of flexability, and I would imagine were the loss is would also play a role in the effect).

If we think about a loss of flexability at each end of a scale length(but within the voiced length). Would that play a more significant role that say in the middle of the scale length? I dunno... I have to figure out how to test that.

I want to be sure everyone understands that I am not implying that other factors here are not effecting what is happening. I believe voiced string length, and dead string length both are factors in what happens when a string is stretched. I believe friction is a real factor. I believe the strength of coupling between the string and what it is attached to plays a role(and of course what that material it is attached to in that equation-body, neck, nut, saddle, etc...), along the same lines lack of coupling would have its effect. I am more or less trying to observe and find factors, why and how they occur. You have to know what factors your dealing with before you can understand interplay between these factors. Of course in most simple paper models we don't take into account the materials and their properties(it becomes very complex very quickly), but that is also why we get unexpected results(and real world models, and observation are so much more telling).

Peace, Rich

P.S. Perry, If I am barking up the wrong tree I would be grateful if you would give me a "drop it" or "keep digging". I may just be off on a wild goose chase wasting my time. Also if I don't get a "drop it", would I be correct in assuming that the idea behind a tapered low B on a bass is developed to help overcome this issue.

Edited April 12, 2007 by fryovanni

[badsnap]

Thanks to Perry and Rich for jogging my memory and clearing things up! I knew that the string length increased and that the tension was distributed across the entire string. I seem to have fired on a dead brain cell (rock and roll does have it's price!?) with my ensuing tension statements. Thanks for helping me to remember the obvious...that the string tension between the nut and bridge would need to be constant to obtain the correct pitch. My apologies to Mikhail for the misinformation. A little research on my part last night confirmed that I was mistaken, and my first priority upon logging into the forum today was to correct that.

Perry...I know you get frustrated sometimes over lazy people not doing the work (as do many of us here) but you need to remember that most of us don't do this for a living, and as such do not have the time and/or equipment to properly (hell, even half assed) perform extensive experiments and research. Hence why we come on here to exchange ideas and information. Some of us consider the discussions on this forum as part of the research. I'm sorry to have caused you any inconvenience and trouble. Thank you very much for the information provided, and in such a nice, logical format.

Peace...Rog

Edit 12 April 07 10:30 PDT - I hadn't read the rest of the posts before posting the original so now...Todd, I love the term "speaking length". I will use that one.

Pardon my lack of in depth knowledge of many stringed instrument terms (I grew up as an organist and drummer). I speak keyboard and percussion well but my guitar leaves a bit to be desired. So sometimes what I'm trying to say doesn't come out quite right, in fact confusing.

Thanks to all for the GREAT information...and no offense is ever taken by me if I am being corrected. I'm here to learn as well as participate and (perhaps) offer some knowledge. I't nice to know that I'm not totally off base in the angle perspective. It's also nice to have an exchange of ideas where we all have something meaningful to contribute.

[Magnus]

Anyway, after fitting the "stopbar" there were several rather noticeable changes: 1) the bad overtones went away (shifted about an octave up the neck and aren't a problem anymore). 2) The overall tone is richer and better balanced, and the low strings have developed a nice Les Paul-ish roundness that wasn't there before. 3) It now plays/feels more like a shorter scale instrument (it's 25 1/2")... as if the tension has been decreased a bit, and the strings feel like they have more give. 4) Not sure, but it seems to have just a tiny bit more resonance. The sustain is just as good as before.

#1 was expected, the rest are pleasant surprises. I'm guessing that the change in feel is due a combination of the slightly reduced string length between the bridge and the stopbar, and a slightly shallower break angle over the saddles. Perhaps the rosewood has something to do with it as well?

Interested to hear your experiences and theories...

Mike

Another newb here.

My experience with this comes from Les Pauls. A lot of you covered some variables that I have not even considered,

but here is my experience.

With most Les Pauls, if you have the tailpiece screwed all the way down to the wood, the strings are stiffer and the tone tends to be a bit harsher and brighter. Now, when you start to raise the tailpiece, the action gets slinkier, easier to play. In addition to that, the tone softens and gets an almost "airy" tone; very nice. Notes just kind of bloom as well.

Kind of like you found out with your discovery, I think a lot of it came from the change in the break angle over the bridge.

String length may have something to do with it, but that is out of my realm of knowledge.

On a Les Paul, I would think that the amount of overall string length just by raising the tailpiece would be rather small, but it may be a factor in the slinky action.

Just my 2¢.

[mikhailgtrski]

In addition to that, the tone softens and gets an almost "airy" tone; very nice. Notes just kind of bloom as well.

A very accurate description.

I suppose on an LP you could also wrap the strings over the top of the stopbar to reduce the break angle.

[rhoads56]

Thanks, yes, Perry aka rhoads56 corrected that mis-statement... he is one of the "sages" around here.

I thought i was just a troublemaker?

Rich, I havent read properly past Mik post. Still tired from a concert last night. I'll read and comment later.

[mikhailgtrski]

I thought i was just a troublemaker?

I don't think those titles are necessarily mutually exclusive...

A little troublemaking now and then is a good thing.

[Magnus]

In addition to that, the tone softens and gets an almost "airy" tone; very nice. Notes just kind of bloom as well.

A very accurate description.

I suppose on an LP you could also wrap the strings over the top of the stopbar to reduce the break angle.

Yes, but that does introduce a longer string length

behind the bridge. Raising the tailpiece minimizes

and addition to the length.

I tried topwrapping, and even with notched saddles,

the strings tended to slip, so I just strung it straight

and raised the tailpiece.

[mikhailgtrski]

Yes, but that does introduce a longer string length

behind the bridge. Raising the tailpiece minimizes

and addition to the length.

I tried topwrapping, and even with notched saddles,

the strings tended to slip, so I just strung it straight

and raised the tailpiece.

Yeah, over-the-top looks 'wrong' to me... the latest Stewmac Trade Secrets newsletter mentioned that Page & Gibbons both prefer it, though. There's really no wrong way, as long as it works and you get the tone you like.

[ToddW]

It would seem fairly obvious that with a lower angle over the top of the bridge, you would let the bridge vibrate more.

This is very smilar to lengthening the the backscale on a piano where the bass string stiffness is actually sufficient to decrease transmision to the soundboard if the backscale is too short.

With a steep down angle on a guitar, for the bridge to vibrate, it has to stretch the very short back scale, or move both the bridge and the tailpiece. With a string through, it would either stretch the string or compress the wood of the body.

With a more shallow angle down, you don't tether the bridge as much because you can bend the short length of string much more readily than you can stretch it.

All this brings up a whole host of questions though about one piece bridges versus bridge and tailpiece, and I guess I'll have to make sure I leave a sufficient back scale on my next project and do some more searching on the best bridge angle in your archives here.

[fryovanni]

It would seem fairly obvious that with a lower angle over the top of the bridge, you would let the bridge vibrate more.

This is very smilar to lengthening the the backscale on a piano where the bass string stiffness is actually sufficient to decrease transmision to the soundboard if the backscale is too short.

With a steep down angle on a guitar, for the bridge to vibrate, it has to stretch the very short back scale, or move both the bridge and the tailpiece. With a string through, it would either stretch the string or compress the wood of the body.

With a more shallow angle down, you don't tether the bridge as much because you can bend the short length of string much more readily than you can stretch it.

All this brings up a whole host of questions though about one piece bridges versus bridge and tailpiece, and I guess I'll have to make sure I leave a sufficient back scale on my next project and do some more searching on the best bridge angle in your archives here.

Todd,

I really like your references to Piano, but remember with and electric instrument you have a more closed system. An acoustic instrument has a much more open system where your primary goal is to move the soundboard. Your piano references are cool because it shows reactions. The effect on sound in an electric may be just the opposite. I have trouble seperating acoustics and electrics in my thinking. On an acoustic making a more efficient transfer of energy to the soundboard will increase output. On an electric an increase in efficiency of transfer will decrease the output, and then return a smaller amount of energy(modified) back to the string(which then can feed the pickup so to say). It is the removal or relflected energy that modifies the sound, but is not the primary driver.

Increases in sustain may be a reaction to transfer of early energy(lowering the amplitude of initial volume) and the body or neck being set in motion, and then the body or necks motion helps to keep the strings moving(as the greater mass of the body or neck will not slow as quickly as the strings). That could of course be totally wrong thinking on my part because I am compairing it to an acoustic bridge.

Honestly it is really hard for me to grasp, but I hope to have a better grasp on things at some point. Hopefully our resident Sage will correct me if I am not thinking straight here .

Peace,Rich