Low pass filter infinite alpha about sndfilter HOT 5 CLOSED

If rate is integral multiple of freq

It isn't for most values of freq... but let's assume it is.

If freq is set to 441Hz, and rate is set to 44100 samples per second, then omega will be:

2 * PI * 441 / 44100 = 0.06283185307179585

Then sn and cs will be:

Sin(0.06283185307179585) = 0.06279051952931336
Cos(0.06283185307179585) = 0.9980267284282716

That being said, now that I'm looking at the code, if freq <= 0 or >= rate/2, then it looks like your logic is right -- sn will be 0, which gets a divide by zero. If I trace the sources of freq, I can see that a user could pass in a 0 for basslpf in the advanced options, and cause that to happen.

So I think the clamp should probably be fixed.

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I just run into the case that freq >= rate/2 with default settings with all presets other than LARGEHALL1 and LARGEHALL2. With the same input, only LARGEHALL1 and LARGEHALL2 work, all other presets will zero out the samples because of the divide by zero issue.

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I don't have time to fix at the moment, but a quick fix is to simply change the biquad coefficients to be a passthrough. In order to do that, you set b0 to 1, and the rest (b1, b2, a1, a2) to 0.

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I don't have time to fix at the moment, but a quick fix is to simply change the biquad coefficients to be a passthrough. In order to do that, you set b0 to 1, and the rest (b1, b2, a1, a2) to 0.

I set alpha to 1 when sn is 0, which seemed to work as expected.

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thanks, sorry it took so long to fix, I don't check here often but I had some free time today

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