The FM Bass
Two sines, one modulating the other, and the spectrum is a Bessel function. Measured against the arithmetic at every ratio and index the page offers, the worst sideband is 0.18 dB out. At an index of 2.405 the first zero of J0 takes the note out of its own sound, 80 dB down while the sound stays loud, and a decaying index passes through that null 62 ms into every note, predicted at 61. At a ratio of 1 or 2 the folded sidebands land back on the note and the null only half happens.







