String Type: The material and construction of the string itself can influence its tone. B strings are typically made of a combination of materials, and some types, such as nickel-plated steel or bronze-wound, may naturally produce a brighter, thinner sound that some perceive as tinny.
String Tension: If the B string has relatively low tension compared to the other strings, it can vibrate more freely and produce a looser, less focused sound. Ensuring proper string tension during tuning can help improve intonation and reduce "tinny" overtones.
Guitar's Design and Build: Different guitars have inherent tonal characteristics determined by their size, shape, and material choices. Certain body types or wood combinations may emphasize certain frequencies or harmonics, affecting the overall sonic response of the strings.
Saddle and Nut Adjustments: Incorrectly adjusted string saddles or nut slots can alter the string's intonation and tone. Improper break angles or poorly cut slots can create unwanted overtones and affect the sustain of the string.
String Height: Strings set too high above the fretboard can produce a "sitar-like" buzzing sound, especially on the thinner strings like the B string. Adjusting the truss rod and bridge properly can optimize the action and reduce unnecessary overtones.
Dampening Elements: The presence or absence of sound-dampening materials inside the guitar, such as bracing or lining, can impact the tonal characteristics of the instrument. Insufficient dampening can cause excessive reflections and resonances, leading to the "tinny" sound.
Playing Technique: While not directly related to the string itself, the player's technique can also contribute to the perceived sound. Using a lighter touch or different picking techniques can alter the tone of the string.
By considering these factors and making appropriate adjustments to the string, guitar setup, and playing technique, you can tame the "tinny" sound and coax a warmer, more balanced tone from the B string on your acoustic guitar.