Non-Polarized Electrolytic Capacitors ERSE's 10%DF line of Non-Polar Electrolytic Capacitors are an excellent choice for speaker crossover building and feature a low 5% tolerance. The 10% DF Non-Polar caps are perfect for crossover networks of bandpass and low pass systems. ERSE 10% DF NPE caps have excellent frequency characteristics and are very linear verses frequency.