# Method for Resonant Frequency Attenuation in Dynamic Audio Equalizer
## 1 Introduction  
An equalizer is a tool utilized for manipulating the spectral characteristics of an audio signal, including the amplitude and phase of the signal. In contrast, a dynamic process modifies the amplitude and envelope of a signal. Equalization changes amplitude in thefrequency domain, whereas dynamic processors alter amplitude in the time domain [1]. Consequently, a dynamic equalizer modifies the frequency response curve of an audio signal in accordance with the input signal only under certain conditions. A condition is when the input signal exceeds or falls below a predefined threshold. The dynamic equalizer may find specific use in the protection/enhancement of professional audio equipment [2]. The discipline of digital signal processing enables the design and development of automated tools to address complex problems. Digital signal processing technology makes it possible to design effects with greater complexity and precision. For instance, effects based on analysis/synthesis techniques can be applied in real time [3]. Before automated tools, only professionals in the field were able to provide partial solutions to these problems with simple tools. One example of manual processing is the attenuation of resonant frequencies in audio files. In [PERSON] et al. [4], twenty-two mixing engineers with different levels of experience were asked to identify and reduce the amplitude of frequencies they deemed resonant with a parametric equalizer in 16 audio files exhibiting frequency defects. The results demonstrated that the overall agreement in the narrowband analysis was less than 50%. This indicates that manually detecting and attenuating frequency resonances represents a significant challenge for audio engineers. In addition, a static equalizer is unable to attenuate resonant frequencies in an audio file, given that the harmonic components of sound change over time. There are two types of static equalizers: parametric and graphic. The parametric equalizer allows the operator to add a peak or a notch at an arbitrary location in the audio spectrum, making it the most flexible of the different types of equalizers. In parametric equalizers, multiple sections are typically connected in cascade [5]. Midrange bands in a parametric equalizer have three parameters: gain, center frequency, and bandwidth. Graphic equalizers are a fixed set of equalizers, where the center frequencies and bandwidths are preset and only gain is adjustable [5]. Common graphic equalizer designs have approximately 30 filters, which can be used to manipulate the frequency response of each audio [1]. In contrast, dynamic equalizers apply frequency amplitude processing with static thresholds. Dynamic equalizers enable conventional equalizers to modify the equalization curve in a manner that is responsive to time. This is made possible by their incorporation of dynamic range compressor parameters, including threshold, ratio, and, in certain instances, attack and release. The equalization stage is able to respond dynamically to the input signal level [1]. A limited number of plug-in equalizers function as resonance suppressors in audio files. An audio plug-in is a collection of software programs that process an audio signal [6]. These programs have their own graphics module for on-screen display. Some commercial plug-ins that have the function of attenuating resonant frequencies are Soothe2 [7] developed by oeksound and RESO [8] developed by Mastering the Mix. Soothe2 is a dynamic resonance suppressor that is capable of automatically detecting resonances over the entire frequency range. The software is capable of identifying problematic resonances in real time and applying corresponding reductions automatically. RESO is a dynamic resonance suppressor that is designed to analyze and identify specific frequencies that exhibit energy buildup. It then proposes nodes in the spectrum that work as static equalizers, which reduce the amplitude at certain frequencies.