So there is this subtractive/wavetable synth called circle that has an amazing dual filter that allows you to set it in parallel or series. I believe I get how both modes work. To recreate a series with eq's I'd literally add an eq to my effects rack and then just another one after that since I believe most other channel racks operate from top to bottom as well. Parallel though I'm not too sure how to create. To my understanding , a parallel circuit splits your signal in half , each half goes through x effect(s) and the halves come back together to make your final sound. I'm not sure how I'd recreate this with filters. But I'd rather just really get a vst for the job.