Car Audio / Passive Crossovers, Narrow Band Pass Calculator

Use these formulas to calculate values for Narrow Band Pass filters only! These are completely different formulas than the ones used here, and should only be used when the low pass frequency is less than 20 times the high pass frequency. Remember, the low pass frequency (F2) is higher than the high pass frequency (F1).

Before clicking for the crossover component values, enter the net impedance level and the desired crossover frequencies. Values should be rounded off to the nearest hundredth.

If you need a 16 mHy coil, you can series a 12.8 mHy coil and a 3.2 mHy coil. If you need a 70 µfd capacitor, you can parallel two 35 µfd capacitors.When the exact value of a coil or capacitor is not available, you can substitute values of ± 5%.

Crossover Calculators: • High Pass/Low Pass • Narrow Band Pass • Zobel Passive Crossovers: • Low Pass Filters • High Pass Filters • Band Pass Filters • Narrow Band Pass Filters • Acoustical Output & Power • First Order Filters • Second Order Filters • Third Order Filters • Zobel • 2 Ohm Charts • 4 Ohm Charts • 8 Ohm Charts • Formulas & Calculators

Car Audio: • Glossary of Terms and Definitions • Ohm's Law • Passive Crossovers & Calculators • Metra Application Guides • Power and Ground Cable Sizes • Subwoofer Enclosures & Calculators • Subwoofer Wiring • the12volt's Application Guide • the12volt's Install Bay (forums) • Thiele - Small Parameters • Tools & Equipment

Narrow Band Pass Filter Calculator Net Impedance High Pass Frequency Low Pass Frequency     Ohms Hertz (Hz) Hertz (Hz)     1st Order (6 dB per Octave) Narrow Band Pass (diagram) Formulas for first order only, calculate for L1 first, then C1. L1 = Net Impedance / [(F2 - F1) x 6.283] x 1,000 = L1 in (mHy) Coil - L1 Millihenries (mHy) C1 = 1 / (39.472 x [L1/1000] x [F1 x F2]) x 1,000,000 = C1 in (µfd) Capacitor - C1 Microfarads (µfd) 2nd Order (12 dB per Octave) Narrow Band Pass (diagram) Formulas for second order only, calculate for C1 first, then L2, C2, L1. L1 = 1 / (39.472 x C1 x [F1 x F2]) x 1,000 = L1 in (mHy) Coil - L1 Millihenries (mHy) C1 = .707 / (Net Impedance x 6.283 x [F2 - F1]) x 1,000,000 = C1 in (µfd) Capacitor - C1 Microfarads (µfd) L2 = 1 / (C1 x [6.283 x (F2 - F1)]2) x 1,000 = L2 in (mHy) Coil - L2 Millihenries (mHy) C2 = 1 / (39.472 x L2 x [F1 x F2]) x 1,000,000 = C2 in (µfd) Capacitor - C2 Microfarads (µfd) 3rd Order (18 dB per Octave) Narrow Band Pass (diagram) Formulas for third order only, calaculate for L3 first, then C2, C3, L2, L1, C1. L1 = 1 / (.499849 x [6.283 x (F2 - F1)]2 x C2) x 1,000 = L1 in (mHy) Coil - L1 Millihenries (mHy) C1 = 1 / (39.472 x [F1 x F2] x L1) x 1,000,000 = C1 in (µfd) Capacitor - C1 Microfarads (µfd) L2 = 1 / (39.472 x [F1 x F2] x C2) x 1,000 = L2 in (mHy) Coil - L2 Millihenries (mHy) C2 = 1 / (1.4884 x [6.283 x (F1 - F2)]2 x L3 x 1,000,000 = C2 in (µfd) Capacitor - C2 Microfarads (µfd) L3 = (.5 x Net Impedance) / (6.283 x [F2 - F1]) x 1,000 = L3 in (mHy) Coil - L3 Millihenries (mHy) C3 = 1 / (39.472 x [F1 x F2] x L3) x 1,000,000 = C3 in (µfd) Capacitor - C3 Microfarads (µfd)

<< Previous - Passive Crossover Formulas and Calculators

Next - Zobel Calculator >>

Crossover Calculators: • High Pass/Low Pass • Narrow Band Pass • Zobel Passive Crossovers: • Low Pass Filters • High Pass Filters • Band Pass Filters • Narrow Band Pass Filters • Acoustical Output & Power • First Order Filters • Second Order Filters • Third Order Filters • Zobel • 2 Ohm Charts • 4 Ohm Charts • 8 Ohm Charts • Formulas & Calculators

Car Audio: • Glossary of Terms and Definitions • Ohm's Law • Passive Crossovers & Calculators • Metra Application Guides • Power and Ground Cable Sizes • Subwoofer Enclosures & Calculators • Subwoofer Wiring • the12volt's Application Guide • the12volt's Install Bay (forums) • Thiele - Small Parameters • Tools & Equipment