Difference Between Overtone and Undertone

Overtone vs Undertone
 

Overtones and undertones are phenomena discussed in waves and vibrations. The concepts of overtone and undertone are mostly discussed in music and other sound related phenomena. The overtones and undertones are very important in producing music, synthesizing music and even singing and production of instruments. It is vital to have a proper understanding in the concepts of overtones and undertones in order to excel in fields such as music, audio engineering, acoustics, waves and vibrations. In this article, we are going to discuss what overtone and undertone are, their similarities, the definitions of overtone and undertone, their applications and finally the difference between overtone and undertone.

What is Overtone?

Overtone is a phenomenon that is directly connected with the resonance and the fundamental frequency of a system. In order to understand the concept of overtone, one must first have an understanding of what fundamental frequency is. Fundamental frequency is a concept discussed in standing waves. Imagine two identical waves travelling in opposite directions. When these two waves meet, the result is called a standing wave. The equation of a wave travelling in +x direction is y = A sin (ωt – kx), and the equation for a similar wave traveling in the -x direction is y = A sin (ωt + kx). By the principle of superposition, the resultant waveform from the overlapping of these two is y = 2A sin (kx) cos (ωt). This is the equation of a standing wave. As x being the distance from the origin, for a given x value the 2A sin (kx) becomes a constant, and Sin (kx) varies between -1 and +1. Therefore, the maximum amplitude of the system is 2A. The fundamental frequency is a property of the system. An overtone is any frequency that is higher than the fundamental frequency of a system. Overtones are usually generated over the fundamental frequency. The collection of overtones and fundamental frequency is known as partials. Partials, which are integer multiplications of the fundamental frequency, are known as harmonics. The sound a musical instrument produces is a partial. The quality of the sound of an instrument being able to be distinguished from another depends on the partial being produced.

What is Undertone?

An undertone is any frequency that is lower than the fundamental frequency of a system. The integer fractions of the fundamental frequency produce the undertone series. The undertone series is the inverse of the overtone series. The undertone series can be produced by multiplying the length of the system by integer values.