Loudspeaker Passive Crossover - Typical Schematics

3 way, 12 dB/oct schematic Crossover Schematic,
RAB 004A (typical 3 way) -
540 / 3500 Hz, 8 Ω nominal,
12 dB/octave,
approx. 1 dB insertion loss
[Image of this unit]

L1 = 3.3 mH 18 ga. air core
L2 = 3.3 mH 19 ga. air core
L3 = .51 mH 19 ga. air core
L4 = .51 mH 19 ga. air core

C1 = 22 µf NPE 100v + 4 µf NPE 100v
C2 = 22 µf NPE 100v + 4 µf mylar 100v
C3 = 4 µf NPE 100v
C4 = 4 µf mylar 100v

R1 = R2 = 10 Ω 10 w
Cc1 = 22 µf NPE 100v
Cc2 = 4µf NPE 100v

low = Pyle W1270 (12 in., 8 Ω, Fs = 25 Hz)
mid = Philips AD50600SQ (5 in., 8 Ω, Fs = 260 Hz)
high = Peerless KO10DT (1 in. dome, 8 Ω, Fs = 1 kHz)

Note: Marked polarity reversal on mid terminals corrects for phase shift and provides proper driver phase at crossover points. (For most drivers positive to red driver terminals moves piston out.)
4 way, 6 dB/oct schematic Crossover Schematic,
RAB 005 (typical 4 way) -
250 / 1000 / 4000 Hz, 8 Ω nominal,
6 dB/octave;
with provision for bi-amplification at 250 Hz

L1 = 4.8 mH 16 ga. air core
L2 = 1.2 mH 18 ga. air core
L3 = .3 mH 18 ga. air core

C1 = 76 µf NPE 100v + 10 µf mylar 100v
C2 = 10 µf NPE 100v + 10 µf mylar 100v
C3 = 4.7 µf mylar 100v + .47 µf mylar 100v

R1 = 20 Ω 10 w
R2 = R3 = 10 Ω 10 w
Cc1 = 22 µf NPE 100v
Cc2 = 10 µf NPE 100v
Cc3 = 4.7 µf NPE 100v

low = JBL 2225H (15 in., 8 Ω, Fs = 40 Hz)
mid-low = JBL 2118H (8 in., 8 Ω, Fs = 85 Hz)
mid = JBL 2105H (5 in., 8 Ω, Fs = 200 Hz)
high = Peerless KO10DT (1 in. dome, 8 Ω, Fs = 1 kHz)

Note: Older JBL drivers - positive voltage to black terminal moves diaphragm forward.

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Last tinkered with November 27, 2004 - R. A. Booty
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