Parametric EQ Filter

[senaavicenna]

Hi,

I have question regarding biquad frequency response, I created filter base on RBJ filter cookbook and use biquad frequency response (R&D) module but I got very strange frequency response result for LPF, HPF, BPF, and notch filter.
why those filter response showed reverse? I mean the response display in PEQ. what is the problem on it? Please help me!!!
Thank you

regards,

[DSP]

I can't see what you mean?

If you connect an FFT display and a white noise generator you can see the effects match the PEQ graphs:

[senaavicenna]

Thanks for your reply DSP,

Actually, my question is about magnitude frequency response which was not display correctly on it.
I dont know whether the R&D module reverse it or the RBJ formula is not correct.
Please refer to attachment file for your reference, frequency response of LPF, HPF and Notch suppossed to be same as hand writing picture. I hope it will give you clear view about my question.
and I hope you can help me on it.

Thank you very much

reagrds,

[senoadiwibowo]

Hi Senaavicenna,

Please refer to attached file, I hope this is what you want.
I think formula is correct, the only R&D module need to reverse if you use it for HPF, LPF, APF, NOTCH, BPF
thanks

[senaavicenna]

Hi Senoadiwibowo,

Yes this is what I want, Thank you very much

regards,