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Intermediate

Speaker Crossover

Build and test a simple first-order crossover path for a tweeter or small speaker driver.

Safety first, always.

ElectroLab AI teaches theory, low-voltage electronics, and planning concepts. Mains voltage, switchboards, fixed wiring, high-current systems, and legal electrical work must only be performed by licensed electricians where required.

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Two-Way Speaker CrossoverThe tweeter gets a series capacitor, the woofer gets a series inductor, and polarity links let you compare the blend.+-tweeter +returnwoofer +balancepolarity compareAMPlow volumeINPUT+ / -CAPhigh-passTWEETERhighsCOILlow-passWOOFERlowsL-PADoptionalPHASEswap linksStart quietly. A bypassed tweeter capacitor can destroy a tweeter fast.

Audio filter blueprint

Build a simple two-way speaker crossover test board and hear what capacitors, inductors, and polarity do.

Bench time

2-4 hours

Typical parts

$25-$70 AUD

Power

Low-volume amplifier output

You finish with

Two-way crossover learning board

Before the first wire

Know the build before you power it.

Start at low amplifier volume and use inexpensive drivers while experimenting.

Use non-polar capacitors for audio crossover paths.

Inductors and capacitors are starting values; real speaker impedance changes with frequency.

Never short an amplifier output while swapping crossover parts.

Bill of materials

7 parts groups to gather

Check every spec

QtyPartExact specWhat it doesInspect before use
1Woofer or full-range driver4 or 8 ohmPlays lower band.DC resistance and cone movement are healthy.
1Tweeter4 or 8 ohm with safe power ratingPlays higher band.Never test directly at loud low frequencies.
1Series tweeter capacitorNon-polar film/electrolytic, calculated valueBlocks bass from tweeter.Voltage rating suitable for amplifier.
1Series woofer inductorAir-core or ferrite crossover inductorReduces highs to woofer.Wire is intact and resistance is low.
OptionalL-pad resistorsPower resistors for tweeter levelBalances tweeter loudness.Wattage and heat spacing are adequate.
1Terminal strip or boardScrew terminalsMakes part swaps safe.No loose strands or shared accidental terminals.
1Low-volume amplifierStable with speaker impedanceProvides test audio.Start with volume at minimum.

Build boundary

This is a low-power learning crossover. It does not cover high-power PA crossover design, active DSP tuning, or valuable speaker restoration without measurement gear.

Part modules vary. Read the markings and datasheet for the exact board in front of you before applying power.