I have an impulse response ir that I need to approximate with an iir because of realtime requirements. For stability I want to break down the 10th order IIR generated with Steiglitz-Mcbride to biquads / second-order sections. However, I can't use tf2sos with the complex transfer function that stmcb() generates like the following:
[b,a] = stmcb(ir,10,10); [sos,g] = tf2sos(real(b),real(a));
When I compare bode plots of
I find that the contour is preserved but there is a large difference in magnitude and phase. Am I missing some scaling factor or limitation? Thanks for any help.