Hey
Within the sliceKIT Biquad filter demo project, how come if I set the frequency cut-off value of a high-pass filter to below 250Hz the audio IO just cuts out? I'm trying to create a low cut filter that needs to go down to 20 Hz.
Thanks.
High pass Biquad filter issue
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millenliam
- Member++
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johned
- XCore Addict
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- Joined: Tue Mar 26, 2013 12:10 pm
Hi Liam,
The biquad example uses a single biquad and a simple algorithm to calculate the cut-off frequency. The end result is that it is not possible to implement very narrow band filters. To do this you will need to use a higher order filter and a digital filter design program to calculate the coefficients.
This applications note discusses adding DSP functions to the USB audio reference design and includes more details about what is possible on xCORE :
https://www.xmos.com/published/adding-d ... nce-design
More extensive DSP code is available on our github repository :
https://github.com/xcore/sc_dsp_filters
Best regards,
John
The biquad example uses a single biquad and a simple algorithm to calculate the cut-off frequency. The end result is that it is not possible to implement very narrow band filters. To do this you will need to use a higher order filter and a digital filter design program to calculate the coefficients.
This applications note discusses adding DSP functions to the USB audio reference design and includes more details about what is possible on xCORE :
https://www.xmos.com/published/adding-d ... nce-design
More extensive DSP code is available on our github repository :
https://github.com/xcore/sc_dsp_filters
Best regards,
John