Sine Design

SB Acoustics SB17NRX2C35-4

midwoofer · EBP 88 → suits either box · nominal (full) — SB Acoustics datasheet (manufacturer)

Thiele/Small parameters

Fs (resonance)36 Hz
Qts0.37
Qes / Qms0.41 / 4.49
Vas27.6 L
Re / nominal Z3.1 Ω / 4 Ω
Xmax5.5 mm
Sensitivity86.8 dB (1 W/1 m, calc); 90 dB (2.83 V/1 m, mfr)
Power handling60 W

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

Recommended enclosures

Sealed (Qtc 0.707) — Vb10.4 L
Sealed — Fc / F368.8 / 68.8 Hz
Ported (suggested) — Vb20.7 L
Ported — Fb / F339.3 / 39.8 Hz

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About this driver

The SB Acoustics SB17NRX2C35-4 is a 6″ midwoofer with a free-air resonance of 36 Hz and a total Q (Qts) of 0.37. Its efficiency-bandwidth product (EBP) of 88 points toward either alignment. In a 10.4 L sealed box it reaches an F3 of 68.8 Hz (Qtc 0.707); a suggested 20.7 L box tuned to 39.3 Hz extends to about 39.8 Hz. See the sealed vs ported guide for how to choose.

Xmax = (coil 16 mm - gap 5 mm)/2; rated 90 dB is nominal (independent ~86-88 dB).

Recommended partners

modeled estimate

The tweeters below pair well with the SB Acoustics SB17NRX2C35-4 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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