Sine Design

SB Acoustics SB12PFCR25-4

fullrange · EBP 118 → suits a ported box · nominal (full) — SB Acoustics datasheet (https://sbacoustics.com/wp-content/uploads/2025/01/4in-SB12PFCR25-4.pdf)

Thiele/Small parameters

Fs (resonance)58 Hz
Qts0.43
Qes / Qms0.49 / 3.4
Vas5.2 L
Re / nominal Z— / —
Xmax
Sensitivity87.5 dB (2.83 V/1 m, mfr)
Power handling30 W

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

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

T/S are full — fetch the datasheet for the full parameters to model a box.

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About this driver

The SB Acoustics SB12PFCR25-4 is a 4″ fullrange with a free-air resonance of 58 Hz and a total Q (Qts) of 0.43. Its efficiency-bandwidth product (EBP) of 118 points toward a ported alignment. See the sealed vs ported guide for how to choose.

Recommended partners

modeled estimate

The tweeters below pair well with the SB Acoustics SB12PFCR25-4 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.

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