Ninety-six hours in artificial sweat raised the damping (loss factor) of a wound guitar string at its 147 Hz fundamental from 0.0015 to 0.0137, roughly nine times higher (Segura Alcaraz et al., Heliyon 2024). That is what “dead strings” look like in a lab. Salt-spray ageing cut the stiffness of acoustic guitar strings by 63.9% after 345 hours (Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026), and pressing an uncompensated string to the first fret pushed the note 64.3 cents sharp (Varieschi and Gower, American Journal of Physics 2010). Market figures live in our guitar sales statistics; this roundup is about what happens on the string itself. We aggregated data from the Journal of the Acoustical Society of America, Acta Acustica, Acoustical Science and Technology, the American Journal of Physics, Heliyon, MDPI Materials and Acoustics, ISMA and DAFx proceedings, a US patent and D’Addario’s technical notes.
TL;DR
- A wound D string’s loss factor rose from 0.0015 to 0.0137 after 96 hours of artificial sweat (Segura Alcaraz et al., Heliyon 2024).
- Accelerated salt spray cut string stiffness by 63.9% after 345 hours (Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026).
- A 0.300 mm 1st string in a phosphor bronze set carried 112 N of tension (Kodama et al., Acoustical Science and Technology 2023).
- Doubling a string’s pitch at the same scale length takes four times the tension (D’Addario tension formula, vendor technical note).
- An open low E acoustic tone showed an inharmonicity coefficient of about 1.12 x 10^-4 (Hodgkinson, Timoney and Lazzarini, DAFx 2010).
- Pressing a string to the first fret made it up to 64.3 cents sharp before compensation (Varieschi and Gower, American Journal of Physics 2010).
- Nylon strings in a lab test took several weeks to stop creeping when left alone (Lynch-Aird and Woodhouse, Materials 2017).
- The fundamental of an open low E took 5.45 s to fall 15 dB, the 3rd harmonic only 0.86 s (Rau et al., ISMA 2017).
- A dead spot opened a decay-time gap of more than 2 s against neighbouring frets (Pate, Le Carrou and Fabre, JASA 2014).
- On average 16.7 of 21 listeners spotted soundboard damping changes, but preference did not shift significantly (Acoustics 2025).
1. Tension per Gauge: The Physics and the Newtons in Practice
String tension is the pulling force a tuned string puts on the neck and bridge. Three things set it: how heavy the string is per unit of length (its “unit weight” or linear density), the vibrating length (scale length) and the target pitch. Because tension grows with the square of frequency, raising a string one octave at the same length takes four times the pull, which is why gauge, not just tuning, decides how a set feels under the fingers.
The table mixes values from three peer-reviewed studies with vendor rows. D’Addario’s formula is standard physics written in imperial units; its “balanced tension” figure is the company’s own design claim. The study rows show how wide the spread is: the same 1st-string slot carried 82 N in one nylon set and 112 N in a phosphor bronze set (Kodama et al., Acoustical Science and Technology 2023).
| Metric | Value | Source |
|---|---|---|
| Tension formula (tension in pounds; UW = unit weight in lb/in, L = scale length in inches, F = frequency in Hz) | T = (UW x (2 x L x F)^2) / 386.4; multiply by 4.45 for newtons | D’Addario, All About String Tension (vendor technical note) |
| Tension change needed to double the frequency of the same string at the same scale length | 4 times (from (2F)^2 = 4F^2 in the formula above) | Derived from the D’Addario formula |
| Tension reported for the 1st string of a phosphor bronze set (0.300 mm, 0.600 g/m) | 112 N | Kodama et al., Acoustical Science and Technology 2023 |
| Tension reported for the wound 3rd string of the same set (0.634 mm, 2.300 g/m) | 148 N | Kodama et al., Acoustical Science and Technology 2023 |
| Tension reported for nylon 1st strings vs fluorocarbon 1st strings (two sets each) | 81 to 82 N vs 100 to 107 N | Kodama et al., Acoustical Science and Technology 2023 |
| Tension of the G string (open G3, 196 Hz, 0.629 m vibrating length) on a Les Paul Junior replica | 69.43 N | Pate, Le Carrou and Fabre, JASA 2014 |
| Axial force on a D’Addario NW026 wound string tuned to 147 Hz | 89 N | Segura Alcaraz et al., Heliyon 2024 |
| Spread of tension between strings in D’Addario balanced-tension sets | Usually within 1 lb | D’Addario (vendor’s own claim) |
Context note: fluorocarbon trebles are denser than nylon, so a thinner fluorocarbon string reaches the same pitch at a higher tension. The Les Paul figure is the tension listed in the string-parameter table (Table I) of the JASA 2014 paper.
2. Pitch Stability: Creep, Temperature and Fretting
A string’s tension is not fixed once it is tuned. Polymer strings keep stretching (creep), temperature shifts the pitch, and pressing a string onto a fret stretches it a little and makes the note sharp. On an uncompensated test string, the first fret came out 64.3 cents sharp, more than half a semitone, which is why guitar saddles are set back and angled (Varieschi and Gower, American Journal of Physics 2010).
The nylon rows come from harp strings, the closest published long-term data on monofilament nylon under musical tension (Lynch-Aird and Woodhouse, Materials 2017). Most recent available data: Lynch-Aird and Woodhouse 2017; SN Applied Sciences 2020; Varieschi and Gower 2010; Hodgkinson et al. 2010.
| Metric | Value | Source |
|---|---|---|
| Working tension of a monofilament nylon string vs the value predicted from its unstretched linear density | About 10% lower | Lynch-Aird and Woodhouse, Materials 2017 |
| Strain (stretch) reached by nylon harp strings under tension | Up to 20% | Lynch-Aird and Woodhouse, Materials 2017 |
| Time for a new nylon string to stop creeping, left alone vs over-tuned by 6% (about one semitone) for about three days | Several weeks vs about one week | Lynch-Aird and Woodhouse, Materials 2017 |
| Pitch drift with temperature in many of the nylon strings tested (smallest perceptible pitch change: about 3 cents) | More than 1.5 cents per °C | Lynch-Aird and Woodhouse, Materials 2017 |
| Pitch glide right after the pluck, open low E tone on an acoustic guitar | 83.4 Hz at onset to 82.8 Hz at rest (about 12.5 cents) | Hodgkinson, Timoney and Lazzarini, DAFx 2010 |
| Pitch glide of a tapered bass string (open) vs a lumped-construction bass string (all positions) | 1.75 cents per second vs less than 4 cents per second | SN Applied Sciences 2020, inharmonicity in bass guitar strings |
| Sharpening of a fretted note with no compensation (C3 test string, 645 mm scale) | +14.3 to +64.3 cents (+64.3 at fret 1, +30.9 at fret 12) | Varieschi and Gower, American Journal of Physics 2010 |
| Same test string after saddle and nut compensation | -7.9 to +7.3 cents | Varieschi and Gower, American Journal of Physics 2010 |
Math note: the 12.5-cent glide is our conversion of the paper’s two frequencies, 1200 x log2(83.4 / 82.8) = 12.5 cents. The glide happens because a hard pluck briefly raises the average tension, which then relaxes as the vibration dies. The bass glide figures come from the SN Applied Sciences 2020 study of tapered and lumped string designs.
3. Inharmonicity: Why Overtones Run Slightly Sharp
An ideal string would produce overtones at exact whole-number multiples of its fundamental. A real string is a thin, stiff bar, and that stiffness pushes each higher partial a little sharp; the coefficient B measures how much. An open low E tone on an acoustic guitar measured B of about 1.12 x 10^-4, and the value kept shifting as the note decayed (Hodgkinson, Timoney and Lazzarini, DAFx 2010). Small as it looks, Jont Allen wrote in 2005 that “A tiny value of B … leads to a huge perceptual effect.”
Material matters as much as gauge: on the 3rd string at fret 13, nylon sets stretched the 10th partial further than a phosphor bronze set did. Wound strings are also harder to predict than plain ones: Murray and Whitfield found that measured B agreed very well with a model for monofilament strings but poorly for wound strings (American Journal of Physics 2022). Most recent available data: Kodama et al. 2023; Murray and Whitfield 2022; Hodgkinson et al. 2010.
| Metric | Value | Source |
|---|---|---|
| Inharmonicity coefficient B, open low E tone, acoustic guitar | About 1.12 x 10^-4 | Hodgkinson, Timoney and Lazzarini, DAFx 2010 |
| B at the start of the note vs once the note settles | 1.1 x 10^-4 vs 1.14 x 10^-4 | Hodgkinson, Timoney and Lazzarini, DAFx 2010 |
| Time constant of the fall in pitch vs time constant of the change in B, same tone | 0.38 s vs 0.23 s | Hodgkinson, Timoney and Lazzarini, DAFx 2010 |
| Measured ratio of the 10th partial to the fundamental, 3rd string at fret 13, phosphor bronze set (perfectly harmonic = 10.00) | 10.05 | Kodama et al., Acoustical Science and Technology 2023 |
| Same ratio, two nylon sets vs two fluorocarbon sets | 10.28 and 10.24 vs 10.15 and 10.13 | Kodama et al., Acoustical Science and Technology 2023 |
| Agreement between measured B and B calculated from a string model | Very good for monofilament strings, poor for wound strings | Murray and Whitfield, American Journal of Physics 2022 |
Context note: B also moves within a single note. In the DAFx tone, it settled with a time constant of 0.23 s, faster than the pitch itself (0.38 s), so the first fraction of a second of a pluck is the least harmonic part of the sound.
4. Partial Decay: How Fast Each Overtone Dies
Sustain is not one number. Every partial decays at its own rate, and the brightness of a note is mostly the race between them. On a hollow-body electric’s open low E, the fundamental took 5.45 s to fall 15 dB while the 3rd harmonic needed only 0.86 s (Rau et al., ISMA 2017). A 2026 bass-string study reached the same verdict: the higher harmonics “are damped much faster than the lower ones” (Vibration 2026).
The string itself loses very little energy per cycle; the body, the frets and the string material do the rest. Steel-string guitar modes decayed with time constants of 300 to 400 ms against 100 to 200 ms on banjos (Woodhouse et al., Acta Acustica 2021). Most recent available data for most rows: Kodama et al. 2023; Woodhouse et al. 2021; Rau et al. 2017. Sustain is judged by ear, often at stage volume, and our roundup on musician hearing loss and noise exposure covers what that volume does to the ear doing the judging.
| Metric | Value | Source |
|---|---|---|
| Time for the 1st harmonic of the open low E to fall 15 dB (hollow-body electric, flatwound strings) | 5.45 s | Rau et al., ISMA 2017 |
| Same measure, 2nd harmonic | 4.49 s | Rau et al., ISMA 2017 |
| Same measure, 3rd, 4th and 5th harmonics | 0.86 s, 0.87 s and 1.12 s | Rau et al., ISMA 2017 |
| Decay time constants of string modes up to about 1 kHz, steel-string guitar vs banjo | 300 to 400 ms vs 100 to 200 ms | Woodhouse et al., Acta Acustica 2021 |
| Q-factor of string modes vs body modes (higher Q = slower decay) | A few thousand vs around 100 or lower | Woodhouse et al., Acta Acustica 2021 |
| Attenuation of the 10th mode on nylon and fluorocarbon strings fretted at fret 13 vs fret 1 | About 10 times higher, time constant only 0.05 s | Kodama et al., Acoustical Science and Technology 2023 |
| String-loss coefficient of fluorocarbon vs nylon strings, as estimated from the paper’s equation | About 0.37 times | Kodama et al., Acoustical Science and Technology 2023 |
Context note: the studies use different yardsticks (a 15 dB drop, a time constant, an attenuation coefficient), so compare trends, not raw seconds. Rau et al. also found their model predicted 13.29 s for the fundamental against 5.45 s measured, a reminder that losses at the neck “should not be neglected.”
5. Ageing, Corrosion and Coatings: How Strings Go Dead
The folklore says old strings sound dull because something in their pitch structure changes. The measurements say otherwise. Jont Allen expected the inharmonicity coefficient to change with age but found that “the damping of the high partials changed and that was the real source of the aging effect” (Allen, Catgut Acoustical Society Newsletter 1976, as described by the author). In the 2024 sweat test, the unprotected string’s total sound power density fell from 2.9927 x 10^-4 to 2.2467 x 10^-5 Pa²/Hz, about 13 times lower, with “significant harmonics loss” from 2000 Hz up (Segura Alcaraz et al., Heliyon 2024).
The artificial sweat was 0.5% sodium chloride, 0.1% lactic acid and 0.1% urea at pH 6.5. A 2026 accelerated study on acoustic strings with high-carbon steel cores and bronze windings saw the same direction of travel in the metal itself: polarization resistance dropped from 25,027 to 15,445 Ω·cm² in the first hour of salt spray, and stiffness fell by more than 60% (Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026). Coating data is thin: the only numeric coated-versus-uncoated decay test we found is in a coating maker’s patent, so it is labelled as such.
| Metric | Value | Source |
|---|---|---|
| Loss factor at the 147 Hz fundamental, new string vs unprotected string after 96 h in artificial sweat | 0.0015 vs 0.0137 | Segura Alcaraz et al., Heliyon 2024 |
| Same loss factor, string protected by impressed-current cathodic protection after 96 h | 0.0041 | Segura Alcaraz et al., Heliyon 2024 |
| Mass loss after 96 h in artificial sweat, unprotected vs protected string | 0.0245 g (1%) vs 0.0153 g (0.6%) | Segura Alcaraz et al., Heliyon 2024 |
| Loss of string stiffness (storage modulus) after 345 h of salt spray | 63.9% (2.02 x 10^11 Pa to 0.73 x 10^11 Pa) | Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026 |
| Polarization resistance (resistance to corrosion) at 0 h, 1 h and 170 h of salt spray | 25,027, 15,445 and 1,387 Ω·cm² | Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026 |
| Decay rate of a low E (46E) string, coated vs uncoated | -3.41 vs -4.61 dB/sec | US Patent 9502008, Cleartone (coating maker’s patent) |
| Decay rate of an A (36A) string, coated vs uncoated | -4.48 vs -4.17 dB/sec | US Patent 9502008, Cleartone (coating maker’s patent) |
Context note: the patent’s D (26D) string decayed at -4.21 dB/sec coated versus -5.12 uncoated, so the coating slowed decay on two of the three strings and sped it up on one (US Patent 9502008). An earlier experimental dissertation on nickel-plated electric strings found no significant dependence between stress-driven and corrosion-driven degradation (Connolly, Trinity College Dublin 2010).
6. Sustain by Construction: Necks, Players and Dead Spots
Because the string loses so little energy on its own, the structure it is anchored to decides much of the sustain. A dead spot is a fret where the neck resonates at the note’s frequency and drains energy out of the string. On an electric guitar built as a Les Paul Junior replica, a dead spot at fret 12 opened a decay-time gap of more than 2 s against its neighbours, while the electromagnetic pickup added no damping at all (Pate, Le Carrou and Fabre, JASA 2014).
Holding the guitar barely moves its resonances, but it does change damping (Le Carrou, Pate and Chomette, JASA 2019). For the factory side of acoustic guitars, see our acoustic guitar manufacturing statistics. Most recent available data for the electric-guitar rows: Le Carrou et al. 2019; Pate et al. 2014; Fleischer 1999.
| Metric | Value | Source |
|---|---|---|
| Decay-time gap between a dead spot at fret 12 and neighbouring frets, G string, Les Paul Junior replica | More than 2 s | Pate, Le Carrou and Fabre, JASA 2014 |
| Largest difference between measured and model-predicted decay time (T30, time to fall 30 dB) | 0.6 s | Pate, Le Carrou and Fabre, JASA 2014 |
| T30 of synthesized electric guitar notes with the guitar hanging free (no player) | 3 to 8 s | Le Carrou, Pate and Chomette, JASA 2019 |
| Shift in structural mode frequencies when a player holds the guitar | Less than 5% (modes 1 and 2), less than 2.5% (modes 3 to 6) | Le Carrou, Pate and Chomette, JASA 2019 |
| Neck mode behind a fret-12 dead spot vs the note it absorbs | About 373.81 Hz vs G4 at 392.00 Hz | Le Carrou, Pate and Chomette, JASA 2019 |
| Neck resonance behind a dead spot at the 4th fret of the D string, Stratocaster-type guitar | Out-of-plane resonance at 430 Hz | Fleischer, ASA/EAA/DAGA Berlin 1999 |
| Bridge admittance (how easily the bridge moves) of banjos vs guitars above 300 Hz | 20 to 30 dB higher | Woodhouse et al., Acta Acustica 2021 |
| Listeners who correctly picked the hidden reference among steel-string guitars with different soundboard damping | 16.7 of 21 on average | Acoustics 2025, soundboard damping study |
Context note: in the 2025 soundboard study, the authors concluded that varying soundboard damping “seemed to have no practically relevant influence” on the guitar they tested, even though most listeners could hear a difference (Acoustics 2025). Fleischer defined sustain as the time to a 30 dB drop and called neck conductance a key parameter for diagnosing dead spots (Fleischer, ASA lay-language paper 1999). A 2025 Forum Acusticum paper rated open-string sustain at 4.1 ± 0.9 for a reference guitar versus 3.1 ± 1.2 for a 3D-printed guitar on a five-point scale (Espinoza et al., Forum Acusticum 2025).
Summary: Guitar String Tension, Gauge and Tone Decay by the Numbers
| Metric | Value | Source |
|---|---|---|
| Loss factor at 147 Hz, new string vs after 96 h of artificial sweat | 0.0015 vs 0.0137 | Segura Alcaraz et al., Heliyon 2024 |
| String stiffness lost after 345 h of salt spray | 63.9% | Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026 |
| Polarization resistance, start vs after 170 h of salt spray | 25,027 vs 1,387 Ω·cm² | Rodriguez-Tejon et al., Corrosion and Materials Degradation 2026 |
| Tension change to double a string’s frequency at the same length | 4 times | Derived from the D’Addario formula |
| Working tension of nylon vs value from unstretched density | About 10% lower | Lynch-Aird and Woodhouse, Materials 2017 |
| Uncompensated sharpening at fret 1 | +64.3 cents | Varieschi and Gower, American Journal of Physics 2010 |
| Fretting error range after saddle and nut compensation | -7.9 to +7.3 cents | Varieschi and Gower, American Journal of Physics 2010 |
| Pitch glide after a pluck, open low E acoustic tone | 83.4 Hz to 82.8 Hz (about 12.5 cents) | Hodgkinson, Timoney and Lazzarini, DAFx 2010 |
| Inharmonicity coefficient B, open low E acoustic tone | About 1.12 x 10^-4 | Hodgkinson, Timoney and Lazzarini, DAFx 2010 |
| 10th partial vs fundamental, nylon vs phosphor bronze (ideal 10.00) | 10.28 vs 10.05 | Kodama et al., Acoustical Science and Technology 2023 |
| Measured vs modelled B agreement | Very good for monofilament, poor for wound | Murray and Whitfield, American Journal of Physics 2022 |
| 15 dB decay, 1st vs 3rd harmonic, open low E | 5.45 s vs 0.86 s | Rau et al., ISMA 2017 |
| Decay time constants, guitar vs banjo string modes | 300 to 400 ms vs 100 to 200 ms | Woodhouse et al., Acta Acustica 2021 |
| Coated vs uncoated low E decay rate | -3.41 vs -4.61 dB/sec | US Patent 9502008, Cleartone (vendor patent) |
| Coated vs uncoated A string decay rate | -4.48 vs -4.17 dB/sec | US Patent 9502008, Cleartone (vendor patent) |
| Dead spot decay-time gap at fret 12 | More than 2 s | Pate, Le Carrou and Fabre, JASA 2014 |
| Neck resonance behind a D-string dead spot | 430 Hz | Fleischer, ASA/EAA/DAGA Berlin 1999 |
| Listeners spotting soundboard damping changes | 16.7 of 21 on average | Acoustics 2025, soundboard damping study |
Methodology and Sources
- Segura Alcaraz, Bonastre Cano, Julia Sanchis, Gadea Borrell and Cases Iborra, “Evaluation of the acoustic performance of a novelty cathodic protection system against guitar steel strings corrosion”, Heliyon 2024
- Rodriguez-Tejon et al., “Degradation of Metal Guitar Strings: Corrosion-Induced Mechanical Damage and Electrochemical Analysis Under Accelerated Conditions”, Corrosion and Materials Degradation 2026
- Kodama, Sato, Hoshika and Yokoyama, attenuation of nylon, fluorocarbon and phosphor bronze strings, Acoustical Science and Technology 2023
- Pate, Le Carrou and Fabre, “Predicting the decay time of solid body electric guitar tones”, JASA 2014
- Le Carrou, Pate and Chomette, “Influence of the player on the dynamics of the electric guitar”, JASA 2019
- Rau, Maestre, Smith and Scavone, guitar neck admittance at different stopping positions, ISMA 2017
- Woodhouse et al., “Acoustics of the banjo: measurements and sound synthesis”, Acta Acustica 2021
- Hodgkinson, Timoney and Lazzarini, “A Model of Partial Tracks for Tension-Modulated Steel-String Guitar Tones”, DAFx-10 2010
- Varieschi and Gower, “Intonation and Compensation of Fretted String Instruments”, American Journal of Physics 2010
- Murray and Whitfield, “Inharmonicity in plucked guitar strings”, American Journal of Physics 2022
- Lynch-Aird and Woodhouse, “Mechanical Properties of Nylon Harp Strings”, Materials 2017
- SN Applied Sciences 2020, “On inharmonicity in bass guitar strings with application to tapered and lumped constructions”
- Vibration 2026, “Modeling Bass Guitar String Vibration with Frequency- and Fret-Dependent Damping for Real-Time Sound Generation”
- Acoustics 2025, “Evaluation of Soundboard Damping Variations on Physical and Perceptual Aspects of the Sound of a Steel-String Acoustic Guitar”
- Espinoza et al., “Perceptual Comparison Between a Low-Cost Guitar and a 3D-Printed Guitar”, Forum Acusticum 2025
- Fleischer, dead spots of electric guitars and basses, ASA/EAA/DAGA Berlin 1999 lay-language paper
- Allen, “On the aging of steel guitar strings”, Catgut Acoustical Society Newsletter 1976, as summarized by the author in 2005
- Connolly, “Degradation Process in Nickel Plated Electric Guitar Strings: An Experimental Study”, Trinity College Dublin 2010
- US Patent 9502008, “Methods and apparatus for improving decibel level decay rates of excited strings”, assigned to Cleartone
- D’Addario, All About String Tension (vendor technical note)
- Data watch: most string-physics measurements predate late 2023, so older figures are flagged as most recent available data in each section. The decay figures use different yardsticks (15 dB drop, 30 dB drop, time constant, dB per second) and cannot be compared directly. The Heliyon 2024 paper states that protected strings showed “400 % higher polarisation resistance and 60 % lower mass loss”, but its own table (2402 vs 668 Ω·cm², 0.0153 g vs 0.0245 g) gives about 3.6 times the resistance and about 38% less mass loss, so we report only the raw values. The coated-string decay rates come from a patent owned by a coating maker, cover three strings, and the patent text contradicts itself on peak levels. Manufacturer tension charts are vendor data and were kept to a minority of rows; D’Addario’s downloadable chart now redirects to an interactive calculator, so no per-gauge vendor values are quoted. The Forum Acusticum 2025 ratings do not state a listener count in the text we read. Murray and Whitfield’s numeric B values sit behind a paywall and are not quoted.
- Last updated: November 7, 2026. We update this roundup quarterly, and the next refresh is expected when the next issues of the Journal of the Acoustical Society of America and Acta Acustica publish new guitar-string measurements.