# Method for Resonant Frequency Attenuation in Dynamic Audio Equalizer
## 4 Conclusions  
The analysis of a greater number of samples in the frequency domain allows for greater precision in the analysis of low frequencies. The plug-in of the present work demonstrates superior performance at these frequencies, as evidenced by the tests conducted on audio samples belonging to the percussion group. This is due to the fact that the plug-in in question generates attenuation at frequencies below 250 Hz, with attenuation values ranging from \(-0.8\) dB to \(-1.25\) dB. In contrast, the attenuation generated by Soothe2 and RESO is close to 0 dB. The algorithm generates a curve using the standard deviation rule of thumb and linear interpolation functions as a threshold curve for detecting resonant frequencies. This is because the peaks of the signal are neglected, resulting in a general shape of the spectrum. The energy accumulation is higher in specific areas, which can be observed in this curve. The utilization of octave band-based analysis enables the estimation of resonance attenuation without the necessity of identifying each specific resonant frequency. Matching the detection zones with commercial tools such as Soothe2 confirms that the algorithm adequately captures the resonance patterns. This similarity is due to the fact that the architecture of Soothe2 is similar to that of the algorithm. The present work and Soothe2 employ a dynamic filter approach, continuously analyzing the signal and proposing filters based on the buffer size. This contrasts with RESO, which analyzes a fixed section of the audio and proposes static filters for the entire audio. The second-order filter section processes the signal with minimum and stable phase filters. This is due to the amplitude and frequency considerations made, which ensure that the poles and zeros of the filter remain within the unit circle of the Z-plane. In the comparison of the developed system with commercial plug-ins, the attenuation generated by the developed system was found to be higher. The average attenuation generated by the plug-in was found to be adequate, as an intermediate point of attenuation between 0 dB and 6 dB is required. This is because attenuation higher than \(-0.25\) dB is barely perceptible to the human ear, while attenuation lower than \(-6\) dB reduces sound perception by half. The attenuation falls within the specified range and is also higher than that of the other two commercial plug-ins. The attenuation zone where there is agreement between the three systems is from 500 Hz to 4 kHz. Based on the equal loudness curves, the 4 kHz zone is of particular importance because it is the most sensitive to the human ear. A system was thus developed to detect and attenuate resonant frequencies in audio files, with satisfactory results. The plug-in performs optimally on audio signals originating from voices and instruments such as drums and guitars. In other audio signals, such as those originating from wind or other instruments, the proposed plug-in attenuates more than other commercial plug-ins, yet it does not ensure that the attenuation occurs over resonant frequencies. Frequency band-based analysis proves to be a valid strategy to evaluate the effectiveness of a system without the need to identify individual resonant frequencies. Since energy build-up in certain bands is a reliable indicator of problematic resonances, this approach allows conclusions to be drawn on groups of audios in a general way. Given our development of an actual plug-in in VST format, it is possible to implement our work in any DAW or system that reads this format. This enables the processing of audio files for various applications, including production, mixing, and mastering of music, as well as voice in movies, podcasts, and radio. Additionally, some digital mixers provide support for this format, which can be utilized to eliminate feedback and adjust audio levels in live sound.