Principles of equalizer in sound processing

The function of the balancer is to adjust the signal strength at different frequencies.
As a wave, sound has three elements: amplitude, frequency, and phase. The amplitude determines the sound size, and the frequency determines the sound tone. The actual sound is often not a single frequency wave, but a superposition of various frequencies, thus forming a distinctive sound.
Y = Asin (wt + FI) + a0 (single frequency Acoustic Wave Description)
Y = a1sin (w1t + fi1) + a2sin (w2t + fi2) +... (actual Acoustic Wave Description)
The difference between sound is that different frequencies of sound signals have different intensity. The balancer is implemented based on this principle.
The balancer can automatically separate signals of different frequencies and zoom in or out to varying degrees to change the sound effect. Currently, the balancer supports both hardware implementation (such as saa7709 hardware equalizer) and software implementation (such as mute ). Of course, in principle, there can be either an equalizer that processes analog signals or a digital signal.

Generally, a human can hear a frequency band (20Hz-20 kHz) divided into multiple frequency bands, the acoustic signals in different frequencies are amplified or reduced to varying degrees (gain or negative gain ). For example, swap mute is divided into 10 frequency bands. The saa7709 hardware balancer has 20 hardware units. When the 2x10 mode is adopted, the sound signal can be divided into 10 frequencies (sections). When the 4x5 mode is adopted, it can be divided into five frequencies (sections ).