First Order (6db/octave) Two-Way Crossover

High Pass Impedance: Ohms
Low Pass Impedance: Ohms
Frequency Hz C1= µF

L1= mH

 Phase shift on a first-order crossover is 90 degrees.

Second Order (12db/octave) Two-Way Crossover

High Pass Impedance: Ohms
Low Pass Impedance: Ohms
Frequency Hz C1 = µF

L1 = mH

C2 = µF

L2 = mH

 - Linkwitz-Riley crossovers match attenuation slopes so that system response is flat at crossover point. - Butterworth crossovers yield to a peak at the crossover frequency. - Bessel crossovers have a frequency response between Linkwitz-Riley and Butterworth crossovers. - The phase shift on a second-order crossover is 180 degrees (reversed polarity).

Third Order (18db/octave) Two-Way Crossover

High Pass Impedance: Ohms
Low Pass Impedance: Ohms
Frequency Hz C1 = µF
C2 = µF
L1 = mH

L2 = mH
L3 = mH
C3 = µF

 Phase shift on a third-order crossover is 270 degrees (-90 degrees).

Fourth order (24dB/octave) Two-Way Crossover

High Pass Impedance: Ohms
Low Pass Impedance: Ohms
Frequency Hz C1 = µF
C2 = µF
L1 = mH
L2 = mH

C3 = µF
C4 = µF
L3 = mH
L4 = mH

 The phase shift on a fourth-order crossover is 360 degrees = 0 degrees (no phase shift).

Zobel Circuit (Impedance Stabilization)

DC resistance (Re): Ohms
Inductive Equivalent (Le): Henries C1= µF

R1= Ohms

 - Even though speakers are rated at a certain "resistance" (i.e. 4 Ohms), the actual impedance varies with frequency (speakers have inductance). To compensate for the non-linearity of speakers (on mainly subwoofers), Zobel circuits are used. - Re is the DC resistance of the woofer (can be measured with an ohmmeter) - Le (or Lces) is the electrical inductive equivalent of the driver.

Driver Impedance = Ohms
Desired Attenuation = dB R1 = Ohms

R2 = Ohms

 - An L-pad circuit will attenuate a speaker. - L-pads keep the load "seen" by the amplifier constant, affecting only the power delivered to the speaker.  The power delivered by the amplifier remains constant. - Since L-pads are made from resistors, it does not induce any phase shifts, or affect frequency response.