This paper proposes a low-latency quasi-linear-phase octave graphic equalizer. The structure is derived from a recent linear-phase graphic equalizer based on interpolated finite impulse response (IFIR) filters. The proposed system reduces the total latency of the previous equalizer by implementing a hybrid structure. An infinite impulse response (IIR) shelving filter is used in the structure to implement the first band of the equalizer, whereas the rest of the band filters are realized with the linear-phase FIR structure. The introduction of the IIR filter causes a nonlinear phase response in the low frequencies, but the total latency is reduced by 50% in comparison to the linear-phase equalizer. The proposed graphic equalizer is useful in real-time audio processing, where only little latency is tolerated.
A LOW-LATENCY QUASI-LINEAR-PHASE OCTAVE GRAPHIC EQUALIZER / Bruschi, V.; Valimaki, V.; Liski, J.; Cecchi, S.. - 3:(2022), pp. 94-100. (Intervento presentato al convegno 25th International Conference on Digital Audio Effects, DAFx 2022 tenutosi a aut nel 2022).