Linear Phase FIR low pass required

[nitsuj]

I'm in need of a linear phase FIR low pass for oversampling x2.

I've tried a few existing jsfx libraries (and some forum code) but they either don't work properly when you analyze frequency or they don't null (which they should).

Before I reinvent the wheel, just asking if anyone has a solid one in the public domain?

[mschnell]

As an example for my FFT experiments, I used a JSFX called "Frequency Splitter" or similar.

I suppose this is a zero phase FIR Filter.

-Michael

[nitsuj]

Thanks - I checked it out.

You're right, if you split and output to the same channel you can get it to null so I'm concluding that there's no phase shift - it's linear phase.

I didn't have much luck repurposing the technique but I'll give it another go.

[mschnell]

In this forum you will find a thread where I learned about this "splitter" and how to use the jsfx fft and rfft unctions.

OTOH, I am not sure if fft is the way to go for your FIR Filter project.

-Michael

[SaulT]

The 2x code includes a 19-tap halfband filter, which is linear phase. Longer filters can easily be designed.


https://forum.cockos.com/showthread....t=oversampling