DIY Speaker Crossover Guide - 6 dB/Octave Filter Component Chart (2/4/8 Ohm)

This document is a car-audio reference page titled 'Setting the Filter Constant' and 'Component Guide,' explaining how to build simple 6 dB/octave passive speaker crossover filters. It shows three circuit diagrams with frequency-response curves: a low-pass filter using a series inductor (L1) for subwoofers/woofers, a high-pass filter using a series capacitor (C1) for mid/mid-high speakers, and a band-pass filter combining an inductor (L2) and capacitor (C2) for mid-bass/mid drivers. Notes explain that a multi-channel system can be set up with a combination of filters, that the inductance (L) and capacitance (C) determine the crossover frequency (fc), and that non-polarized capacitors rated at or over ±25 V must be used for C1 and C2 to prevent a safety hazard due to amplifier output voltage. The Component Guide table lists required inductor (mH) and capacitor (µF) values for 2 Ω, 4 Ω, and 8 Ω speaker load impedances across crossover frequencies from 50 Hz to 10,000 Hz (50, 80, 125, 200, 320, 500, 800, 1,250, 2,000, 3,200, 5,000, 8,000, and 10,000 Hz). A reader can use this page to select the correct coil and capacitor values for a homemade crossover at a chosen crossover frequency and speaker impedance.