I'm on the very last section of the code for my current SigmaDSP project (using the ADAU1701) but have run into a problem when manually entering coefficient data for some IIR filters.
As I understand it, the coefficients are all in 5.23 format and can therefore have values up to (nearly) +/-16.000. However, I am unable to enter negative values larger than -5.000 into the b1 coefficient box - higher values are clipped to -5.000. The other coefficient boxes will all accept the full expected range, and b1 will accept larger positive numbers.
This occurs with both the index-slectable and fixed second-order filters and - of course - my filter needs a b1 value over -5.000.
Is this a quirk of SigmaStudio, or is there something special about b1 which I am not aware of? If the former, is there a workaround?
BTW, I saw that v3.4 of SigmaStudio claimed to fix an IIR Coefficient Window bug and hurriedly installed the upgrade, but it has made no difference.
Any help would be much appreciated!