FDA Tool

While exporting IIR filter coefficients into workspace, I get an option of SOS Matrix and Scale Values.What does "Scale values" option do?

Answer 1

[Rick Rosson]

The SOS Matrix is an M x 6 matrix that provides the unscaled coefficients for the M second-order sections that, when cascaded, implement the filter. The Scale values option outputs an M x 1 column vector G, each element of which is essentially a multiplicative gain factor that you can use simply to scale each second-order section so that the overall filter is referenced to 0 dB. So G does not affect the shape of the output waveform or spectrum, but it does affect the scale or level of the output or spectrum.

Does that make sense?

Rick

[Sohaib Fakhar]

thanx a lot.xtremely greatful

[abhishek singh]

sir, i got SOS and G for my bandpass filter and now wants to apply it in C code to filter an audio . how can i do that.i still don't get idea how to apply these coefficients as i need to neglect frequencies that are 3db down