Calculator Inputs
Use the responsive grid below. It displays three columns on large screens, two on medium screens, and one on mobile devices.
Example Data Table
| Scenario | Inputs | Calculated Output |
|---|---|---|
| High-pass from frequency | 8 Ω, 3000 Hz | Capacitor ≈ 6.6315 µF |
| Low-pass from frequency | 8 Ω, 2500 Hz | Inductor ≈ 0.5093 mH |
| Two-way from frequency | 8 Ω woofer, 8 Ω tweeter, 2200 Hz | L ≈ 0.5787 mH, C ≈ 9.0428 µF |
| Two-way from components | 8 Ω, 8 Ω, 0.56 mH, 8.2 µF | LP ≈ 2273.64 Hz, HP ≈ 2425.26 Hz |
Formula Used
1) First-order High-pass Crossover
Frequency from capacitor: fc = 1 / (2πRC)
Capacitor from frequency: C = 1 / (2πRfc)
Capacitive reactance: XC = 1 / (2πfC)
2) First-order Low-pass Crossover
Frequency from inductor: fc = R / (2πL)
Inductor from frequency: L = R / (2πfc)
Inductive reactance: XL = 2πfL
3) Additional Engineering Outputs
Angular frequency: ω = 2πf
Period: T = 1 / f
Wavelength: λ = c / f
First-order slope: 6 dB per octave
How to Use This Calculator
Step 1
Choose a network type: high-pass, low-pass, or a two-way first-order crossover.
Step 2
Select whether you want to find component values from a target frequency or find crossover frequency from known components.
Step 3
Enter the driver impedance values. For two-way analysis, enter separate impedances for the low-pass and high-pass branches.
Step 4
Provide target frequency or component values, then add an analysis frequency, tolerance, and graph span for deeper engineering review.
Step 5
Press the calculate button. The page displays results above the form, shows key metrics, and plots the expected response curves.
Step 6
Use the export buttons to save the calculated values as CSV or PDF for design notes, procurement, or project documentation.
Frequently Asked Questions
1) What does crossover frequency mean?
It is the frequency where one filter branch begins handing signal energy to another branch. In ideal first-order passive networks, each branch is about 3 dB down at that point.
2) Why does the calculator ask for impedance?
Passive crossover component values depend directly on the driver’s nominal impedance. An 8 Ω driver needs different capacitor and inductor values than a 4 Ω driver at the same crossover target.
3) Why are real speaker results different from electrical results?
Real drivers do not behave like perfectly resistive loads. Their impedance changes with frequency, and acoustic output also depends on enclosure, placement, and native driver rolloff.
4) What is the benefit of the tolerance field?
It estimates how component manufacturing tolerance can shift the crossover point. This is useful when comparing standard-value parts and checking whether variation still fits your design target.
5) Why is the slope fixed at 6 dB per octave?
This page models first-order passive sections only. First-order networks use one reactive element per branch, which produces a 6 dB per octave electrical attenuation slope.
6) Can I use this for non-audio engineering work?
Yes, the same first-order RC and RL relationships apply broadly. However, the wavelength output assumes acoustic speed of sound, so that part is mainly aimed at speaker crossover work.
7) What does the analysis frequency output show?
It shows reactance and attenuation at a frequency you choose. That helps you inspect behavior above, below, or exactly at the crossover point without changing the design target.
8) Should I still measure the finished crossover?
Yes. This calculator is excellent for design estimates, but measured impedance and acoustic response remain the best way to confirm final crossover alignment in a real system.