IIR block and "Manual" IIR

     Hello leonxp,

     Here's some clarifying data:

     To rough out the frequency responses without external test gear I use a swept VCO and peak detector as shown below:

     The Real-Time Display gives the peak magnitude response from 1KHz to 20KHz.  Both scales are linear, so the results format differently than with the stimulus / probe display.

     This is the feedback portion of your wired filter with one feedback block and one straight delay, and the original coefficients:

     With these feedback coefficients the filter's magnitude output hits the rail (16.0), as shown below.  The General Filter block yields the same result:

     Reducing the manual filter's feedback coefficients by an arbitrary factor of 10 results in this response:

The General Filter block, with the same coefficients except for a1 and a2 signs reversed, provides the same results:

I attached the circuit with the swept VCO that made these plots.  I hope you find all this helpful.

Best regards,

Bob

     Hello leonxp,

     Here's some clarifying data:

     To rough out the frequency responses without external test gear I use a swept VCO and peak detector as shown below:

     The Real-Time Display gives the peak magnitude response from 1KHz to 20KHz.  Both scales are linear, so the results format differently than with the stimulus / probe display.

     This is the feedback portion of your wired filter with one feedback block and one straight delay, and the original coefficients:

     With these feedback coefficients the filter's magnitude output hits the rail (16.0), as shown below.  The General Filter block yields the same result:

     Reducing the manual filter's feedback coefficients by an arbitrary factor of 10 results in this response:

The General Filter block, with the same coefficients except for a1 and a2 signs reversed, provides the same results:

I attached the circuit with the swept VCO that made these plots.  I hope you find all this helpful.

Best regards,

Bob