A Study of Engine Intake Noise Control Based on the Improved Filtered-x Least Mean Square Algorithm

Table 3

Noise reductions at different rotational speeds.

	Noise frequency	Order	Noise amplitude	Error amplitude	Reduction (dB)
1800	60	1	0.1890	0.0194	19.77
	120	2	0.1223	0.0149	18.26
	180	3	0.0339	0.0074	13.25
2400	80	1	0.3765	0.0371	20.12
	160	2	0.0941	0.0180	14.33
	240	3	0.2107	0.0295	17.06
3000	100	1	1.0000	0.0699	23.11
	200	2	0.1590	0.0194	18.26
	300	3	0.1000	0.0148	16.58
3600	120	1	1.2388	0.0944	22.36
	240	2	0.6937	0.0642	20.67
	360	3	0.7804	0.0717	20.73
4200	140	1	3.8397	0.2994	22.16
	280	2	0.3456	0.1062	10.25
	420	3	1.2286	0.1482	18.37