How to calculate parameters for "Dynamic Bass Boost"?

Hello Danny,

It would seem impossible to fathom out all 40 parameters associated with the Dynamic Bass block. Yet under closer inspection, it turns out that this block consists of some old friends -- primarily a compressor and a 2nd order lowpass filter. Their known structures allowed me to figure the thing out. I worked with the Sigma100 (ADAU1701, etc.) version -- generally, parameters apply across the line of SigmaDSPs.

The Dynamic Bass Block's parameter map looks like this:

Address Parameter Comments

0x00 freq_varq This appears to be the frequency parameter for a State-Variable Filter

0x01-05 liir_coeff Biquad coefficients for a 2nd order Butterworth LP filter

0x06-26 compressor LUT 3 dB spaced compressor lookup table

0x27 tconst RMS time constant for compressor

The trick, of course, is to determine how these parameters derive from the values you enter into the block's GUI. This I discerned by extensive experimenting with the Capture Window:

The attached spreadsheet calculates my best approximation of the parameters based upon the block's GUI values. It's in Open Office (.ods) format. You can examine the formulas in this spreadsheet to write your microcontroller code -- thus allowing your final product's end users to adjust the Dynamic Bass as they desire.

Likely the same method could generate similar results for the Bass Enhancement block -- however I've spent way too much time reverse engineering the Dynamic Bass block already.

Best regards,

Bob

Perfect, thank you! I will give it a try.

Regards,

Danny