基于带间干扰模型的音频图示均衡器的设计

Design of graphic equalizer based on inter-band interference

摘要:

图示均衡器传统上由滤波器组实现。由于滤波器组的带间干扰不可避免，传统算法得到的频响曲线与设计要求通常有所偏差，或者是复杂度太大，不适合实时计算。当相邻频段都需要抬升或衰减时，传统算法得到的频响曲线不平坦，有明显波纹。针对此问题，本文研究了滤波器组带间干扰的数学模型，分析了图示均衡器中钟形滤波器的峰值增益与其阻带频响的关系。最后，本文提出了一种基于带间干扰模型的设计方法，利用数值计算列出了参考值，降低了算法复杂度，获得了较为平坦的频响曲线。

Abstract:

Audio graphic equalizers are implemented by filter banks. State-of-the-art algorithms either suffer poor performance in frequency response, or work on high complexity. When two adjacent bands are expected to lift or attenuate by equal amount, huge ripples appear in frequency response. This paper analyzes inter-band interference model, and the relationship between peak gain with its spectral leakage in bell filter. Finally, an offline design method and a reference look-up table are presented to reduce the complexity and eliminate the spectral ripple.