tones

^{"kindly give formula for clculation of ac tones"}

17 * m² / St

Where: m = pluck strength, St = string tension and 17 = a constant prepreseting the age of the average teenager playing Rock-&-Roll in your basement.

Assuming that an ac tone is a sine wave the formula is simply f=1/t

If it is other than a sine wave then you would use the Fourier Series analysis formula.

For example a sawtooth wave would be made up of a fundamental sine wave and harmonics with amplitudes that produce the linear rise and rapid drop.

Periodic wave = dc component + first harmonic + 2nd harmonic + 3rd harmonic + 4th harmonic + . . . . . nth harmonic.

or ν=Vο+V1 sin(ωt+Φ1) +V2 sin(2ωt+Φ2) + V3 sin(3ωt+Φ3) + V4 sin(4ωt+Φ4) +....... + Vn sin(nωt+Φn)

In plain english it says that a periodic wave is a superposition of harmonically related sine waves. Voltage v is the value of the periodic wave at any instant of time; we can calculate this value by adding the dc component and the instantaneous values of the harmonics.

The first term in the Fourier series is V0; this is a constant and represents the dc component. The coefficients Vl, V2, V3, . . . , Vn are peak values of the harmonics. The angles φ1, φ2, φ3,..... φn are phase angles of the harmonics. Radian frequency ω equals 2πf1; as we see, each succeeding term in the Fourier series represents the next higher harmonic.
Theoretically, the harmonics continue to infinity, that is, n has no upper limit. Often, five to ten harmonics are enough to synthesize a periodic wave to within 5 percent with the right combination of amplitudes (V1, V2, V3, . . . , Vn) and angles (φ1, φ2, φ3, . . . , φn) we can produce any periodic waveform.

Jon