Hi all,

I am new to sigmaDSPs and I have a question regarding parameter changing without SigmaStudio. Let´s take for example a simple three band EQ.

I can follow the changings in the capture window and could get these infos to feed the microcontroller which in turn communicates with the DSP via I2C.

This is an excerpt of the capture window:

Safeload Write ParamName: EQ1940Single20B1 Param Value: 1.91170489788055

Safeload Write Param Name: EQ1940Single21B1 Param Value: -3.23407685756683

Safeload Write Param Name: EQ1940Single22B1 Param Value: 1.40179359912872

Safeload Write Param Name: EQ1940Single21A1 Param Value: 1.56372106075287

Safeload Write Param Name: EQ1940Single22A1 Param Value: -0.643142700195313

Maybe I missed some documents, but I really have no idea how I could calc my own coefficients for let´s say changing from peak to shelving or simply to move the corner frequency - just getting this capture info above. Is there any more documentation regarding the internal filter structures? Or is my approach or thinking wrong?

Please help.

best,

rastariot

The SigmaStudio help documentation includes the equations that are used to calculate the filter coefficients. You can find these equations under Algorithm Information > EQ.

SigmaStudio also includes a tool for generating tables of filter coefficients. Under the Tools menu, there is a filter table generator that you can use to generate coefficients for a range of filters, such as 31 peaking EQ filters with a center frequency of 1000 Hz, at a boost setting of +15 to -15 dB in 1 dB steps.