Sine Design

Dayton Audio RS125-4

woofer · EBP 127 → suits a ported box · nominal (full) — Dayton Audio RS125-4 spec sheet (manufacturer)

Thiele/Small parameters

Fs (resonance)57.2 Hz
Qts0.37
Qes / Qms0.45 / 2.04
Vas5.3 L
Re / nominal Z2.9 Ω / 4 Ω
Xmax4.0 mm
Sensitivity85.3 dB (1 W/1 m, calc); 89.9 dB (2.83 V/1 m, mfr)
Power handling30 W

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

Recommended enclosures

Sealed (Qtc 0.707) — Vb2.0 L
Sealed — Fc / F3109.3 / 109.3 Hz
Ported (suggested) — Vb4.0 L
Ported — Fb / F362.5 / 63.3 Hz

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 Dayton Audio RS125-4 is a 5″ woofer with a free-air resonance of 57.2 Hz and a total Q (Qts) of 0.37. Its efficiency-bandwidth product (EBP) of 127 points toward a ported alignment. In a 2.0 L sealed box it reaches an F3 of 109.3 Hz (Qtc 0.707); a suggested 4.0 L box tuned to 62.5 Hz extends to about 63.3 Hz. See the sealed vs ported guide for how to choose.

NOMINAL/manufacturer (Dayton spec sheet). Fs 57.2 Hz; Vas 5.29 L; Sd 52.8 cm2; BL 3.63 Tm; Mms 5.7 g; sensitivity 89.9 dB (2.83V/1m); usable 65-5400 Hz; Xmax 4.0 mm; 30 W. Aluminum Reference cone (sharp metal breakup above passband; datasheet prints no breakup-peak Hz).

Recommended partners

modeled estimate

The tweeters below pair well with the Dayton Audio RS125-4 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.

Related woofers