An Adaptive Asymmetric Parallel Graphic Equalizer Correction Method without Overlapping Frequency Bands
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摘要: 针对车载音响的声场校正精度低、效率低的问题,该文提出一种无重叠频带的自适应非对称并联图示均衡器校正方法。在车载音响声场动态变化情况下,该方法考虑了有效均衡范围和自适应增益,而不是经典方法中的固定均衡范围和人工给定的增益。通过对实测数据进行实验分析,所提方法比经典方法所用均衡滤波器个数平均减少大约20%,拟合目标增益更准确,校正后频谱曲线更平坦。Abstract: In order to solve the problem of low accuracy and low efficiency of car loudspeakers sound field correction, a correction method of adaptive asymmetric parallel graphic equalizer without overlapping frequency bands is proposed in this paper. In the case of the dynamic change of the sound field in the car, the proposed method takes into account the effective equalization range and adaptive gains, rather than the fixed equalization range and given artificially gains in the classical methods. Through the experimental analysis of the measured data, the average number of equalization filters used by the proposed method is about 20% less than the classical methods, whose fitting target gains is more accurate, and the spectrum curve is flatter after correction.
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表 1 车载扬声器分类及其频响范围表
车载扬声器分类 常见频率响应范围 低音 20~150 Hz 中音 150 Hz~5 kHz 高音 5~20 kHz 中低音 20 Hz~5 kHz 中高音 110 Hz~20 kHz 全频段 50 Hz~20 kHz 表 2 1/3倍频程中心频率和带宽
频带编号 $ {f_{\text{c}}} $(Hz) $ {f_{\text{B}}} $(Hz) 频带编号 $ {f_{\text{c}}} $(Hz) $ {f_{\text{B}}} $(Hz) 1 20 9.3 17 800 373 2 25 11.7 18 1000 466.2 3 31.5 14.7 19 1250 582.8 4 40 18.6 20 1600 745.9 5 50 23.3 21 2000 932.4 6 63 29.4 22 2500 1166 7 80 37.3 23 3150 1469 8 100 46.6 24 4000 1865 9 125 58.3 25 5000 2331 10 160 74.6 26 6300 2937 11 200 93.2 27 8000 3730 12 250 116.6 28 10000 4662 13 315 146.9 29 12500 5828 14 400 186.5 30 16000 7459 15 500 233.1 31 20000 9324 16 630 293.7 表 3 不同方法指标对比
指标 ACGE PGE APGE AG-APGE 平均拟合最大误差(dB) 1.08 2.65 1.07 0.23 平均原始SFM 0.652 0.652 0.652 0.652 平均校正后SFM 0.987 0.980 0.986 0.991 平均均衡滤波器个数 31 62 31 25 平均设计所需时间 0.57 ms 1.22 s 0.70 ms 0.48 ms 平均操作数 加法 124 248 124 100 乘法 155 249 125 101 总和 279 497 249 201 -
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