The Ultimate Guide to Acoustic Guitar Strings: Types, Gauges, and Tones

Acoustic guitar strings are arguably the most crucial element in shaping your instrument’s voice. Unlike electric guitars, where pickups and amplifiers heavily influence the sound, acoustic guitars rely entirely on the strings to vibrate and resonate through the soundboard, creating their unique tone. Choosing the right set of acoustic guitar strings can dramatically impact playability, tone, and overall performance. Whether you’re a beginner just starting your musical journey or a seasoned professional seeking to refine your sound, understanding the nuances of acoustic guitar strings is essential.

In this comprehensive guide, we’ll dive deep into the world of acoustic guitar strings, drawing on insights from Brian Vance, Director of Product Development at D’Addario & Co., a leading string manufacturer. We’ll explore the different materials, constructions, gauges, and coatings available, helping you make informed decisions to unlock your acoustic guitar’s full potential.

Acoustic Guitar Strings – Phosphor Bronze

The Critical Role of Acoustic Guitar Strings

While electric guitar strings play a vital role in tone, the relationship between acoustic guitar strings and the instrument is even more intertwined and critical. With electric guitars, the degradation of string tone over time is often gradual and can be compensated for with amplifier adjustments. However, an acoustic guitar’s sound is directly and immediately affected by the strings. The strings are the engine that drives the acoustic guitar’s voice. Their condition and type directly dictate the instrument’s resonance, volume, and overall tonal character.

Understanding the strings you use, their material composition, construction, and age, is paramount to maximizing your acoustic guitar’s sound and playability. Just like changing the oil in a car, regularly replacing your acoustic strings with the right type is a fundamental aspect of guitar maintenance and tone optimization.

A Brief History of Acoustic Guitar String Evolution

The evolution of acoustic guitar strings is closely linked to the development of the acoustic guitar itself. While the modern classical guitar emerged in the mid-19th century, the archtop acoustic guitar, pioneered by Orville Gibson in the late 1800s, marked a significant turning point.

Gibson’s archtop design produced greater volume, enabling guitars to compete with louder instruments like banjos and horns in ensembles. This increase in volume demand necessitated stronger strings capable of withstanding higher tension. Early acoustic guitars utilized various materials, including steel, copper, silver-plated copper, “commercial bronze” (90/10 bronze), and Monel, each offering different tonal qualities and durability.

The Breakthrough of 80/20 Bronze

A pivotal moment in acoustic guitar string history arrived in the 1930s when John D’Addario Sr. collaborated with luthier John D’Angelico. By 1937, they had standardized string gauges (light, medium, heavy) and, more importantly, championed the use of 80/20 bronze alloy. Despite being technically brass, 80/20 bronze (80% copper and 20% zinc) delivered a brighter and louder tone compared to softer alloys and harsh steel strings.

80/20 bronze strings quickly became the industry standard, offering a pleasing acoustic warmth, rich harmonics, and a broad tonal spectrum. For nearly four decades, 80/20 bronze reigned supreme, shaping the sound of acoustic music.

The Rise of Phosphor Bronze

In 1974, another innovation emerged from D’Addario: phosphor bronze strings. Jim D’Addario introduced this new alloy (92% copper, 7% tin, and 1% phosphorus), offering an enhanced balance of warmth and brightness while extending string life. Phosphor bronze strings resist corrosion better than 80/20 bronze, maintaining their tone for a longer period.

Phosphor bronze quickly gained popularity and is now considered the most widely used acoustic string alloy. Its balanced tonal characteristics and extended lifespan have made it the go-to choice for many acoustic guitarists.

Exploring Acoustic String Materials and Their Tonal Impact

Today, acoustic guitarists have a wide array of string materials to choose from, each offering unique tonal characteristics and playing experiences. Let’s explore some of the popular options:

• Phosphor Bronze: As mentioned, the most popular choice. Phosphor bronze strings deliver a balanced tone with warmth and brightness, along with extended string life. They are versatile and well-suited for various musical styles.

• 80/20 Bronze: Offers a brighter and more brilliant tone than phosphor bronze. 80/20 strings are known for their crispness and projection, making them ideal for players who want a lively and articulate sound. They are a great option for guitars with darker tonal characteristics, adding sparkle and clarity.

• Silver Plated Copper: A traditional alloy with a warm and mellow tone, favored for classical, folk, and fingerstyle guitar. Silver-plated copper strings are known for their smooth feel and gentle sound, but they are prone to tarnishing relatively quickly.

• Monel: A nickel-copper alloy (63-67% nickel, 27-34% copper) that produces a warm, “broken-in” tone with good corrosion resistance. Monel strings offer a vintage vibe and a slightly rounder sound, often preferred for blues and roots music.

• Nickel Bronze: Nickel plating over phosphor bronze combines the warmth of phosphor bronze with enhanced clarity and projection from the nickel. Nickel bronze strings offer improved string life and a balanced tone that works well for jazz and fingerstyle playing, enhancing the midrange frequencies and providing a clear, articulate sound.

• Aluminum Bronze: An alloy of aluminum and copper, known for its enhanced clarity, volume, and strong corrosion resistance. Aluminum bronze strings offer a bright and powerful tone with excellent sustain, suitable for players seeking maximum projection and brilliance.

• 85/15 Bronze: A blend of 85% copper and 15% zinc, positioned tonally between phosphor bronze and 80/20 bronze. 85/15 strings offer a balanced tone with a slightly warmer character than 80/20, providing a subtle alternative for players seeking a nuanced sound.

• Stainless Steel: Primarily used for electric guitars due to its bright and aggressive tone, stainless steel can be used on acoustic guitars for players seeking extreme brightness, projection, and long string life. However, they may lack the warmth and richness of traditional acoustic string alloys.

• Nickel-Plated Steel: Similar to stainless steel in brightness, some players, particularly bluegrass flatpickers, use nickel-plated steel electric guitar strings on their acoustics. They believe these strings allow the guitar’s natural wood tone to shine through without the string alloy coloring the sound. D’Addario EJ22 electric guitar strings are sometimes used for this purpose.

Experimenting with different string materials is key to discovering your preferred acoustic guitar tone. Consider the wood of your guitar, your playing style, and the musical genres you play when making your choice.

Coated vs. Uncoated Acoustic Guitar Strings: Longevity and Tone

String life is a significant consideration for acoustic guitarists, as acoustic strings tend to corrode faster than electric strings due to exposure to air and moisture. Coated strings have emerged as a popular solution to extend string life and maintain consistent tone.

Coated Acoustic Guitar Strings: These strings feature a micro-thin polymer coating applied to the wrap wire, protecting it from dirt, oil, and corrosion. Modern coating technologies have advanced significantly, minimizing any tonal compromise and offering a natural feel. Coated strings are ideal for players who want to reduce string changes, especially those who play frequently or in humid environments. Brands like D’Addario XT, Elixir, Ernie Ball, and Martin offer high-quality coated acoustic strings.

Uncoated Acoustic Guitar Strings: Traditional uncoated strings offer a raw and vibrant tone that some players prefer. Uncoated strings generally have a brighter initial tone and may be slightly more responsive to nuances in playing. However, they require more frequent changes to maintain optimal tone and are more susceptible to corrosion.

The choice between coated and uncoated strings depends on your priorities. If string longevity and consistent tone are paramount, coated strings are an excellent choice. If you prioritize the purest, most immediate tone and are willing to change strings more often, uncoated strings may be preferred.

Acoustic Guitar String Construction: Beyond Round Wound

While round wound construction is the standard for acoustic guitar strings, offering maximum volume, resonance, and harmonic complexity, other construction types cater to specific playing styles and tonal preferences.

• Flattops: A D’Addario innovation, Flattops are phosphor bronze strings that are slightly flattened on the top of the round winding wire. This creates a smoother feel and reduces finger noise, similar to half-round electric guitar strings. Flattops are popular among acoustic slide players and bluegrass flatpickers seeking a smoother playing experience.

• Silk and Steel: These strings feature a silver-plated copper wrap wire wound around a steel core, with inner windings of nylon filament material (originally silk). Silk and steel strings are softer to the touch, have lower tension, and produce a mellow, warm tone, often preferred by fingerstyle players seeking a nylon-like sound on a steel-string guitar.

An illustration depicting various acoustic guitar string constructions, including round wound, flat tops, and silk and steel, highlighting the differences in their winding profiles and materials.

Acoustic Guitar String Gauges: Finding the Right Feel and Tone

String gauge refers to the thickness of the strings. Acoustic guitar strings are typically sold in sets with varying gauges for each string, influencing playability, tone, and volume. Choosing the right gauge is crucial for comfort and optimal sound.

Standard acoustic string gauges include extra light, custom light, light, medium, light top/medium bottom, and heavy. However, gauge names can vary between brands, so it’s essential to look at the individual string gauges in millimeters or inches when comparing sets.

Here’s a general overview of D’Addario’s standard 6-string acoustic guitar string gauges:

• Extra Light (10-47): (e: .010, B: .014, G: .023, D: .030, A: .039, E: .047) Very light and easy to play, ideal for beginners and players who prefer low action and minimal finger fatigue. Extra light gauges are also favored for recording due to their even response when strummed and compressed through microphones.

• Custom Light (11-52): (e: .011, B: .015, G: .023, D: .032, A: .042, E: .052) A slightly heavier gauge than extra light, offering a bit more volume and fullness while still maintaining good playability. This was Jim D’Addario’s personal favorite gauge.

• Light (12-53): (e: .012, B: .016, G: .024, D: .032, A: .042, E: .053) The most popular acoustic string gauge, striking a balance between playability and volume. Light gauge strings are versatile and suitable for a wide range of playing styles. Some brands may offer light gauge sets as 12-54.

• Medium (13-56): (e: .013, B: .017, G: .026, D: .035, A: .045, E: .056) Heavier gauge strings produce more volume and a fuller tone, particularly in the bass frequencies. Medium gauge strings require more finger strength and may not be as comfortable for beginners, but they are favored by players seeking maximum projection and a powerful sound. Also suitable for guitars tuned down a half or whole step.

• Light Top/Medium Bottom (12-56): (e: .012, B: .016, G: .025, D: .035, A: .045, E: .056) Also known as “Bluegrass” gauge, this set combines lighter plain strings for easier soloing and bending with heavier wound strings for a powerful bass response and rhythm playing. A good option for Drop D tuning.

• Heavy (14-59): (e: .014, B: .018, G: .027, D: .039, A: .049, E: .059) The heaviest standard gauge, offering maximum volume and low-end response. Heavy gauge strings are typically used by players who tune down or use altered tunings and require significant finger strength.

Balanced Tension and Tuning-Specific Gauges

D’Addario has developed Balanced Tension sets in their Nickel Bronze line, designed to provide a more even feel and tension across all six strings. These sets may feature unconventional gauges but offer a more mathematically balanced playing experience and improved string-to-string volume consistency.

For altered tunings, such as DADGAD, D’Addario offers the EJ24 DADGAD set, which combines gauges from light and medium sets to provide balanced tension and optimal string-to-string volume when tuned to DADGAD.

High-strung/Nashville Tuning sets are also available, effectively octave strings from a 12-string set. Stringing a second acoustic guitar with a Nashville tuning set can create a shimmering, chorus-like effect when recording and layering with a standard-tuned guitar.

Gypsy Jazz strings are uniquely constructed with lighter cores, silver-plated copper windings, and lighter overall gauges to accommodate the longer scale lengths and “spanky” tone of Gypsy Jazz guitars. These strings are often loop-end to fit traditional tailpieces.

Amplifying Acoustic Guitars and String Choice

When amplifying acoustic guitars, the choice of strings can interact differently with various pickup systems:

1. Microphone Systems: Microphones capture the acoustic sound of the guitar naturally, and standard acoustic strings work well. String alloy, gauge, and condition all influence the captured tone.

2. Piezo Pickups: Piezo pickups sense physical vibrations, and string vibration is crucial for a strong signal. String gauge (mass = energy), heavy coatings, and dead strings can negatively impact piezo performance. Fresh, bright strings generally work best with piezo pickups. String alloy differences may be less pronounced with piezo pickups, as they primarily sense vibration rather than tonal nuances.

3. Magnetic Pickups: Acoustic guitars can also be amplified with magnetic pickups. Modern acoustic magnetic pickups are designed to work with standard acoustic strings, despite copper-based alloys being non-ferrous and not ideal for magnetic pickups. Acoustic magnetic pickups compensate for this by using stronger magnets or adjusting magnet placement to capture the magnetic signal from the steel cores of the wound strings. Electric guitar strings used with acoustic magnetic pickups may result in an unbalanced sound.

Conclusion: Experiment and Find Your Acoustic String Sweet Spot

Choosing the right acoustic guitar strings is a journey of exploration and personal preference. Understanding the different materials, constructions, gauges, and coatings available is the first step. Experimenting with various string types on your guitar, considering your playing style and musical goals, will ultimately lead you to discover the perfect set of acoustic guitar strings that unlocks your instrument’s full potential and enhances your musical expression. As Brian Vance suggests, taking a small chance on a new set of strings can truly change your musical life.

View More in the Guitar Strings Series:

What Strings Are Best for Jazz?