SELECT (calculator - narrow band pass)

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    The narrow band pass calculator allows you to design Narrow Band Pass crossover networks. Narrow Band Pass networks are used when the Low Pass side of the crossover is less than 20 times the value of the High Pass side. (Example: LP = 2000Hz and HP = 120Hz) This calculator properly calculates the parts values, adjusting for the "width" of the crossover design.

    Use these formulas for Narrow Band Pass filters only!

    Enter the nominal speaker impedance and the desired crossover frequency.
    Values should be rounded off to the nearest hundredth.

    Impedance

    Ohms    		 High Pass Freq.

    Hertz (Hz)    		 Low Pass Freq.

    Hertz (Hz)

    1stOrder (6dB per Octave) Narrow Band Pass
    Formulas for first order only. Calculate for L1 first, then C1.

    L1 (mH) = Net Impedance / [(F2 - F1) x 6.283] x 1,000 = L1 (mH)
    Inductor -L1

    Millihenries (mH)

    C1 (µf) = 1 / (39.472 x [L1/1000] x [F1 x F2]) x 1,000,000 = C1 (µf)
    Capacitor -C1

    Microfarads (µf)

    2ndOrder (12dB per Octave) Narrow Band Pass
    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 (mH)
    Inductor -L1

    Millihenries (mH)

    C1 = .707 / (Net Impedance x 6.283 x [F2 - F1]) x 1,000,000 = C1 in (µf)
    Capacitor -C1

    Microfarads (µf)

    L2 = 1 / (C1 x [6.283 x (F2 - F1)]2) x 1,000 = L2 in (mH)
    Inductor -L2

    Millihenries (mH)

    C2 = 1 / (39.472 x L2 x [F1 x F2]) x 1,000,000 = C2 in (µf)
    Capacitor -C2

    Microfarads (µf)

    3rd Order (18dB per Octave) Narrow Band Pass
    Formulas for third order only. Calculate 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 (mH)
    Inductor -L1

    Millihenries (mH)

    C1 = 1 / (39.472 x [F1 x F2] x L1) x 1,000,000 = C1 in (µf)
    Capacitor -C1

    Microfarads (µf)

    L2 = 1 / (39.472 x [F1 x F2] x C2) x 1,000 = L2 in (mH)
    Inductor -L2

    Millihenries (mH)

    C2 = 1 / (1.4884 x [6.283 x (F1 - F2)]2 x L3 x 1,000,000 = C2 in (µf)
    Capacitor -C2

    Microfarads (µf)

    L3 = (.5 x Net Impedance) / (6.283 x [F2 - F1]) x 1,000 = L3 in (mH)
    Inductor -L3

    Millihenries (mH)

    C3 = 1 / (39.472 x [F1 x F2] x L3) x 1,000,000 = C3 in (µf)
    Capacitor -C3

    Microfarads (µf)

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