# The effect of string gauge on sustain.

Discussion in 'Strings [BG]' started by BAG, Mar 6, 2016.

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## With all else being equal, does a bigger gauge string result in more or less sustain on a note.

1. ### BAG

May 5, 2014
New Zealand
My daughter had to come up with a science experiment for year ten at school and being into her music she came up with the idea to try and study the effect that different gauge strings have on note sustain.

To keep things manageable it was all done with the low E on an acoustic guitar. She sourced four different gauges of string from our friend at Elixir (i should note that we are not Elixir endorsed but we are lucky enough that the Australian importer supplies us with strings free of charge). We also bought 4 uncoated strings from a guitar shop to compare.

The gauges were: Elixir 47 52 53 56 and uncoated strings 49 52 53 56

The way we went about was to have the guitar on a bench with a large diaphragm condenser mic set up and pointed between the sound hole and neck. Everything was set in such a way that we could ensure it was all in the same position each time.

We recorded to Reaper with me on the computer and Kayla on the guitar. She had to pluck the string and let it ring out. We tried to ensure that the initial attack was similar each time and any that were well over or under -2db were repeated. Each string was recorded 5 times and the wav file graphic on the screen was saved as a screen shot. Each string was re-stringed by me each time so as to be as similar as possible and given a bit of a stretching to take up any slack on the tuning peg.

After all recordings and screen shots were saved they were then imported to Photoshop where the start of the note amplitude was measured in millimeters to the nearest 10th using the photoshop measure tool. She then measured the point at which the note amplitude reduced to 20% of the original amplitude and this gave her the length of time.

This is where things are at the moment and she still has to graph the averaged results and come up with conclusions which should be finished this week.

So far one basic conclusion can be made which is actually the opposite of what I expected at the start of things but is now (sort of) obvious. I'll let you know around the end of the week as to what that is but for now I'm interested to know what other people would assume (or know) to be the case, hence the poll.

I'd also like to know if anyone else has done any accurate research on this topic or knows of any research done in regards to sustain on stringed instruments.

Edit: Results are on page three and some graphs of results on page 4

Last edited: Mar 7, 2016
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2. ### Killed_by_DeathSnaggletooth

I'm going with the higher mass strings having more sustain, due to the rules of inertia.

3. ### ixlramp

Jan 25, 2005
UK
All else equal would be equal tension, but this is all low E, so i'm guessing a thinner looser string would have it's amplitude fall off faster due to initial higher excursion (floppiness), which would be interpreted in this experiment as less sustain.

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4. ### ofajen

Apr 12, 2007
92.4W 38.9N
On an acoustic, I would expect any string thickness difference to be slight, relative to the typical dissipation of energy of the modes of the top, neck, etc. if you make a solid body guitar with concrete, then the string effect might just be observable. Not sure what would be expected. Thinner strings would tend to flex better and perhaps less energy loss.

Otto

5. ### Killed_by_DeathSnaggletooth

Hmm, the extra mass might be compensated for by the extra tension. Too many variables to work it out simply.

Apr 12, 2007
92.4W 38.9N
Probably so.

Otto

7. ### FourBanger

Sep 2, 2012
SE Como
Since he said his results surprised him I was on the fence between either no difference (detectable in this test) or going the opposite of intuition with more sustain appearing on the thinner strings. I voted bigger = less with the deciding rationale being tension causing the arc of vibration being smaller (less amplitude) to begin with and sustain being a matter if loss of said amplitude sooner because the starting point was lower/smaller.

8. ### BAG

May 5, 2014
New Zealand
Good point. "All else being equal" in this case is that the guitar, mic etc is all equal and the same and that the strings are tuned to low E on the guitar. We wanted to find the results in a real world scenario and in the real world a larger gauge string will have different tension to a thinner gauge. The results may possibly be due to the tension more than the actual gauge however in stringed instrument world larger gauge generally means higher tension.

9. ### JustForSport

Nov 17, 2011
IME a looser string (due to a lighter gauge being strung to a lesser tension at the same pitch as all the rest) oscillates more freely and longer than a stiffer/heavier string strung to the same pitch. All this is of course using the same type string- same core type type/different gauge.
Longer oscillation = longer sustain.

Edit: Of course, a string of more flexible construction (round, smaller diameter core, looser wraps) of the same gauge and weight will have more sustain than its hex core/heavy core cousin.

This is more evident on fretless.

Last edited: Mar 6, 2016
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10. ### BAG

May 5, 2014
New Zealand
Interesting rationale and I was debating whether or not to include that comment as it may skew the comments and the poll however I left it in there as some may assume the opposite to you and then second guess themselves due to my surprise at the initial results. If my revelation of a surprising result makes you think about changing your vote you might want to think about the fact that you don't know what my initial assumption was.

Starting to tie myself up in knots here...... i'll just shut up now.

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11. ### BAG

May 5, 2014
New Zealand
And i'll be voting carrots so I can see the poll results as it won't show me how it's going and I don't want others to see any results until they've voted to avoid people voting with the pack too much, although the comments will give an idea as to how people are voting.

EDIT: Awwww....c'mon. Who else voted carrots?? That's just a cop out to see the results.

12. ### ofajen

Apr 12, 2007
92.4W 38.9N
Using the same guitar, are the thicker strings able to witness cleanly in the bridge and the nut slot?

Otto

13. ### FourBanger

Sep 2, 2012
SE Como
Such were reasons I almost went with there not being a detectable difference in this particular experiment. Many factors like that could overcome the actual physics one is trying to test.

14. ### BAG

May 5, 2014
New Zealand
Yep. I've had 56's on this guitar before. In saying that there is obviously the chance that the thinner strings could be affected due to a sloppy nut slot.

And there are so many variables it's not funny and would take a lifetime to test. Such as:
• At what point would tuning down affect the results if at all?
• Would the results be the same using different gauge plain string high E strings?
• Is there a point that going much thicker or thinner gauge reverses the current findings or negates any change?
• Would we get the same results after the strings were well played in getting a bit old and dead? and would the coated strings change in relation to uncoated strings over time, that is if there is any measurable difference?
These and many other questions will NOT be answered in this experiment.

I'm hopeful that the results once fully compiled, averaged, graphed etc might show some definitive conclusion on whether coated strings react in the same manner.

I would have like to be able to rig something up that was capable of plucking the string with the same pressure and velocity every time but for the life of me couldn't think of how to do so. I'd also have liked to do more recording shots of each sting to get a better average however as it is it has taken many hours of work already and I'd rather my daughter play music than do homework.

15. ### Ewoa/k/a Steve CooperSupporting Member

Apr 2, 2008
Huntington WV
Hmn...just pondering it...mulling over which variables are controlled in that design. The guitar is constant, so that takes care of wood properties, bridge, nut, and so forth.

The lighter gauge string would have to be at less tension to produce the same pitch with the same vibrating length. So ya got two variables there which might affect sustain, the gauge and the tension. You could isolate string tension by measuring sustain with the same string tuned to different pitches.

Another is the strength with which the string is plucked. But I guess multiple measurements (with your daughter attempting to keep that consistent) would average out variation in that variable.

16. ### BAG

May 5, 2014
New Zealand
I'm thinking of doing this at some stage as it'll be easier. No string changes, just re-tuning each time. The actual recording part is the easiest. The measuring takes the most time but she has that down pat so a quick test of a couple of notes either side of E would be interesting.

17. ### JustForSport

Nov 17, 2011
Then the thread title should be changed to 'the-effect-of-string-tension-on-sustain.'

It would no longer be a low E string.

Jun 5, 2015
The problem there is that different pitches may resonate better or worse with that particular guitar. a "Wolf" note has little sustain at all and if the pitch to reach desired tension is a wolf its not going to sustain as well as the other strings regardless of gauge.

Really interesting ideas though... I suppose of you used a solid guitar so dense that it didn't vibrate at all you could then test the "sustaining" properties of the string itself. the bridge and tuners would also need to be isolated as well.

Actually a musical instrument is probably the worst thing to try this with. Some type of string holding apparatus like whats used to make strings would probably be best... But that is getting crazy.

Cool experiment for a tenth grader!

19. ### AndyPanda

May 11, 2014
Alameda, California
Just off the top of my head, it seems to me that sustain is a function of how much kinetic energy gets converted to something else (heat from friction - work done vibrating the wood, moving through the magnetic field etc). If the mechanism were frictionless and completely rigid, the string would sustain forever (and produce no sound). So the question becomes does a heavier gauge string give up more or less energy than a lighter gauge string? I certainly don't know the answer - but I'm guessing heavier string sustains less due to transferring a more of its energy to friction and sound. But then the person plucking the string has to put more energy into the heavier string to get it moving in the first place ... or does she?

Since you are measuring the db of the plucked string ... you could also weigh the strings and calculate the energy required to make the string vibrate a certain distance - but a heavier string would not have to vibrate as far to generate the same db ... so it gets really complicated doesn't it?

Since you are going by db (to try and pluck the different strings the same) I think you might get a different answer than you would get if you measured how far the vibrating string moves side to side when plucked. I mean, if you plucked all the strings so they vibrated the same distance (and in that case, I think the heavier strings would be louder than the lighter strings) you'd have a different result from the experiment.

Last edited: Mar 7, 2016
20. ### AndyPanda

May 11, 2014
Alameda, California
Thought about this again ... I'm thinking that a heavy string (more mass) will impart a higher percentage of its energy into making the wood of the guitar vibrate (and therefor sustain less) while a lighter string will impart a lower percentage of its energy into vibrating the guitar and will sustain longer....

looking forward to seeing the results of your experiment