What is the lowest resonant frequency called?

The lowest frequency portion of the electromagnetic spectrum is designated as “radio,” generally considered to have wavelengths within 1 millimeter to 100 kilometers or frequencies within 300 GHz to 3 kHz .

The lowest frequency produced by any particular instrument is known as fundamental frequency . The fundamental frequency is also called the first harmonic of the instrument.

The lowest resonant frequency is called the fundamental , while all higher resonant frequencies are called overtones. All resonant frequencies are multiples of the fundamental, and are called harmonics. The fundamental is the first harmonic, the first overtone is the second harmonic, and so on.