Sine Design

Eminence BETA-12CX

woofer · EBP 90 → suits either box · nominal (full) — Eminence datasheet (https://cdn.shopify.com/s/files/1/0270/8665/1462/files/Beta_12CX.pdf)

Thiele/Small parameters

Fs (resonance)47 Hz
Qts0.48
Qes / Qms0.52 / 5.64
Vas120.9 L
Re / nominal Z5.42 Ω / 8 Ω
Xmax3.5 mm
Sensitivity95.7 dB (1 W/1 m, calc); 97.3 dB (2.83 V/1 m, mfr)

Published (nominal) values, params full — verify by measurement (DATS/REW) before building.

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

Sealed (Qtc 0.707) — Vb103.4 L
Sealed — Fc / F369.2 / 69.2 Hz
Ported (suggested) — Vb214.6 L
Ported — Fb / F339.3 / 35.7 Hz
Open in designer →Use my measured parameters →Buy at Parts Express →

Affiliate disclosure: some links are affiliate links and we may earn a commission on qualifying purchases at no extra cost to you. Prices are estimates at the time of writing; verify on the retailer's site.

About this driver

The Eminence BETA-12CX is a 13″ woofer with a free-air resonance of 47 Hz and a total Q (Qts) of 0.48. Its efficiency-bandwidth product (EBP) of 90 points toward either alignment. In a 103.4 L sealed box it reaches an F3 of 69.2 Hz (Qtc 0.707); a suggested 214.6 L box tuned to 39.3 Hz extends to about 35.7 Hz. See the sealed vs ported guide for how to choose.

Recommended partners

modeled estimate

The tweeters below pair well with the Eminence BETA-12CX in a two-way design — each grade is a modeled estimate of the crossover match, with a suggested crossover point. Open any pair in the guided builder to design the crossover and total the parts.

Modeled estimate from T/S + geometry — no measurements. The verdict is robust; it improves with measured FRD/ZMA data.

Related woofers