Hi and thanks for taking the time to read this post. I am trying to decide component values for 2 parallel capacitors, in an effort to reduce esr, which will be for use as power supply smoothing capacitors to be placed after the bridge rectifier. After examination i noticed that consumer electronic goods generally use 2200uf aluminium electrolytic capacitors bypassed with a one microfarad polypropylene capacitor, the polypropylene operates at a higher frequency at which point the aluminium electrolytic ceases behaving as a true capacitor so cannot continue its filtering role. But will this reduce the total esr, since both capacitors are operating at different frequencies. If i took an aluminium electrolytic capacitor with an esr of 2 ohms and bypassed it with a polypropylene with an esr of 0.03 ohms the resultant esr would be 0.06 ohms, or would it? Many thanks in advance. John.