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DIY Stompboxes => Digital & DSP => Topic started by: Ice-9 on December 03, 2023, 03:02:02 PM

Title: SpinCad EQ type filter question
Post by: Ice-9 on December 03, 2023, 03:02:02 PM
Although I have had a bit play around with SpinCad in the past I usually look at coding in SpinASM. I thought I would see if I could work out a single band EQ type filer with a fixed frequency with a cut/boost of about +/- 10db.

Is there any blocks in SpinCad that would get me somewhere near this type of narrow band cut/boost filter?  I'm a little confused as how I could built this in SpinCad. Any pointers would be great.
Title: Re: SpinCad EQ type filter question
Post by: ElectricDruid on December 03, 2023, 04:14:11 PM
You could do an SVF type of thing easily enough in SpinASM, couldn't you? Then use the bandpass output to either add or subtract from the input?
Title: Re: SpinCad EQ type filter question
Post by: Digital Larry on December 03, 2023, 09:54:41 PM
There's a 1-band EQ which is just a single band taken from a 6-band EQ example.  I'm not sure you can get +10 dB out of it.  Also, it's not a bandpass, it's "peaking" which AFAIK means it's flat outside that range.  Or as ElectricDruid suggested, try the BP output of the SVF.  I don't think these filters auto-adjust to keep from clipping when you change the Q, anyway keep that in mind.

DL
Title: Re: SpinCad EQ type filter question
Post by: Ice-9 on December 04, 2023, 05:47:52 AM
Thanks Tom and Larry, I will follow those ideas and see how it turns out.  :)