Impact-Site-Verification: adc34a7b-9f49-42e9-b7a9-b49fdb888532

Sine Design

Dayton Audio UMII18-22

subwoofer · EBP 33 → suits a sealed box · nominal (full) — Dayton Audio UMII18-22 spec sheet (manufacturer)

Thiele/Small parameters

Fs (resonance)22 Hz
Qts0.53
Qes / Qms0.67 / 2.53
Vas248.2 L
Re / nominal Z4.2 Ω / 4 Ω
Xmax28.0 mm
Sensitivity87.8 dB (1 W/1 m, calc); 90.7 dB (2.83 V/1 m, mfr)
Power handling1200 W

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

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

Sealed (Qtc 0.707) — Vb318.4 L
Sealed — Fc / F329.3 / 29.4 Hz
Ported (suggested) — Vb610.9 L
Ported — Fb / F316.6 / 20.0 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 Dayton Audio UMII18-22 is a 18″ subwoofer with a free-air resonance of 22 Hz and a total Q (Qts) of 0.53. Its efficiency-bandwidth product (EBP) of 33 points toward a sealed alignment. In a 318.4 L sealed box it reaches an F3 of 29.4 Hz (Qtc 0.707); a suggested 610.9 L box tuned to 16.6 Hz extends to about 20.0 Hz. See the sealed vs ported guide for how to choose.

NOMINAL/manufacturer. Ultimax II 18in DVC; dual 2-ohm coils, params measured in series (=> 4 ohm). Fs 22 Hz; Vas 248.2 L; Sd 1184 cm2; BL 19.2 Tm; Mms 420 g; Xmax 28 mm at 70% Bl (Klippel verified); 1200 W AES; usable 20-500 Hz.

Recommended partners

modeled estimate

The tweeters below pair well with the Dayton Audio UMII18-22 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 subwoofers