I'm interested in composing filters for realtime audio processing on an microcontroller (MCU). Ideal frequency response is unity as a default, with deviations up and down at specific freq-domain pointers according scalers, and some type of smooth transition between these points. This is conceptually similar to an equalizer.
For example, you might want to scale the 800Hz response by 1.2, and the 1600Hz response by 0.8. it would then taper to unity everywhere else.
Normally you could sort this out by designing a filter with proper parameters on a PC (eg Scipy), but I don't know if this is viable on an MCU. MCU libs are avail that process signals if you already have coefficients, but don't create coefficients. Could you compose coefficients from various pre-built coefficients?
I've had some success with averaging weighted coefficients, as well as convolving them. Adding seems to work better, but the response still isn't ideal. How would you approach this problem?
Perhaps this could be done by composing weighted overlapping bandpass FIR (or IIR?) kernels across the entire spectrum of interest. Convolve the kernels together, or perhaps add them. (IIR you convolve bandpass filters and add bandstop?)