Fourth-order bandpass.
Both chambers load the driver, while external output comes from the front port. Inspect response, excursion, impedance, and the passband relative to its peak.
Driver parameters
Enclosure design
Port geometry
Drive & radiation
Optional acoustic losses
Leave blank for an ideal lossless port.
Leave blank for no absorption resistance.
Leave blank for an airtight chamber.
Air & conventions
Frequency sweep
Acoustic response
LOG FREQUENCYDriver excursion reaches 14.91 mm, exceeding the 12.50 mm one-way limit within this sweep. Reduce drive or evaluate protection.
Read this result with its assumptions.
Sweep: 10-200 Hz, 241 logarithmic samples. Maxima describe this sampled range, not an unrestricted operating limit.
SPL is at 1 m in ideal half-space. Electrical drive is RMS; displayed excursions and air velocities are one-way peak.
Passband edges enclose the largest sampled peak and use a reference 3 dB below that peak. Other lobes or a narrow peak are not a broad, flat passband.
Units & assumptionsYour calculations run in this browser. No account needed.
The math, in plain sight.
Two chambers. One coupled system.
Two chamber loads
The front chamber is vented and the rear chamber is sealed. Pressures act on opposite faces of the cone, so both acoustic loads must be included. External output is the front port output.
When loss factors are entered, the last expression replaces the ideal chamber compliance admittance. This calculator references both chamber loss factors to the front tuning; port resistance uses Rp = omega_b Lp / Qp.
Driver motion and radiated output
The driver properties follow the relationships published on the Thiele-Small page. Reported -3 dB edges are found numerically relative to the sampled response peak, over the stated sweep.
A peak is not a broad passband
The lumped-port model does not predict every higher-frequency pipe or chamber mode. A bandpass box is not a replacement for appropriate electrical filtering. Narrow peaks need careful interpretation and physical verification.
