What Are the Differences in Capacitors?
There are a wide variety of capacitors available for use in crossover networks, each with their own characteristics. The 3 main types of capacitors are non-polar electrolytic, metallized polypropylene, and film and foil.
Electrolytic capacitors are the most inexpensive, and are generally used when budget is the primary concern. Electrolytic capacitors are often described as imparting a grainy or harsh sound to the input signal. If an electrolytic capacitor is to be used, usually it is best in woofer or subwoofer situations, where the large capacitor values needed make electrolytics the only economically feasible alternative. When electrolytics must be used, a second smaller capacitor of higher quality is often used in parallel to help improve overall performance. The greater the portion of the total capacitance that is made of the higher quality component, the better.
Metallized Polypropylene capacitors are the most widely used in crossovers