Greetings,

One thing I immediately loved about Sigma Studio was the ability to specify a chain of many biquads by their coefficients by loading a text file. Since I often design filters in matlab, it was pretty straightforward to export a set of coefficients to a text file that Sigma Studio can read.

Of course, its also great to be able to directly specify a filter in Sigma Studio by it's Fc and Q (in the case of 2nd-order LP) using the 'General (2nd order) Filter' block, so sometimes that's the easier workflow.

Now, I need to verify the equivalence of some filters designed in Matlab to those specified in Sigma Studio using a 'General LP Filter.' for the same parameters and Fs (measurements indicate a discrepancy!) My question is: ** How can I view/export the coefficients generated by a General LP Filter block for a given set of parameters? **

Thanks!

Thanks Miguel,

I realized that the coefficients must be in the export files, so I started searching through them, and I think I've found them in the .params file. However, the naming convention is puzzling to me. For a filter cell with two second order sections, I see the following parameters in the .params file:

EQ1940Single10B1

EQ1940Single11B1

EQ1940Single12B1

EQ1940Single11A1

EQ1940Single12A1

EQ1940Single10B2

EQ1940Single11B2

EQ1940Single12B2

EQ1940Single11A2

EQ1940Single12A2

Most systems I've worked with denote the numerator coefficients as

[b0 b1 b2]

and denominator coefficients as

[a0 a1 a2]

I'm in the process of verifying now, but It looks like the numerator is

[ EQ1940Single10B1 EQ1940Single11B1 EQ1940Single12B1 ]

and the denominator is

[ 1 EQ1940Single11A1 EQ1940Single12A1 ]

for the 1st second-order section , and

[ EQ1940Single10B2 EQ1940Single11B2 EQ1940Single12B2 ]

_________________________________________________________

[ 1 EQ1940Single11A2 EQ1940Single12A2 ]

for the 2nd second-order section.

Is this correct? can you elaborate on the construction of these parameter names?

Thanks!