How to generate fir filters for 24k, low pass and high pass?

[azraelkuan]

hi, i am runing a exp with 24khz audio, can u help me?

project-NN-Pytorch-scripts/project/hn-nsf/model.py

Lines 594 to 617 in 8c83186

	lp_u = [0.00936455546502, 0.0416254862901, 0.0878313219556,
	0.146086321198, 0.192602581136, 0.211221591449,
	0.192602581136, 0.146086321198, 0.0878313219556,
	0.0416254862901, 0.00936455546502]
	#
	# high-pass for noise-component in voiced region
	# 16kHz, pass-band 7-8K, gain 1, ripple 5dB,
	# stop-band 0-5k, gain 0, ripple -40dB)
	hp_v = [-0.00936455546502148, 0.04162548629009957,
	-0.08783132195564508, 0.1460863211980122,
	-0.19260258113649556, 0.21122159144894015,
	-0.19260258113649556, 0.1460863211980122,
	-0.08783132195564508, 0.04162548629009957,
	-0.00936455546502148]
	#
	# high-pass for noise-component in unvoiced region
	# 16kHz, pass-band 3-8K, gain 1, ripple 5dB,
	# stop-band 0-1k, gain 0, ripple -40dB)
	hp_u = [0.0853841419929, -0.0492022947553, -0.147017860697,
	-0.247377645939, 0.710306785317, -0.247377645939,
	-0.147017860697, -0.0492022947553, 0.0853841419929]

[TonyWangX]

Hi,
(Although I haven't tried experiment on hn-nsf for 24kHz waveforms)

You can use the this website to calculate the filter coefficients
http://t-filter.engineerjs.com

1. Specify sampling freq to 24000 Hz
2. Change the upper bound of the stop/pass-band to 12000 Hz (rather than 8000)

For example, for lp_v,

16kHz:
pass-band 0-5K, gain 1, ripple 5dB,
stop-band 7-8k, gain 0, ripple -40dB

24kHz:
pass-band 0-5K, gain 1, ripple 5dB,
stop-band 7-12k, gain 0, ripple -40dB

I uploaded one figure for the lp_v 24kHz configuration. The filter coefficients are shown on the right side.

Similarly, you may get the filter coefficients for other FIR filters.

[azraelkuan]

thanks!