Aura Sound NS18-992-4A

18" · 4 Ω · 800 W · 93.2 dB · datasheet ↗

Thiele-Small parameters

Nominal size	18"
Impedance	4 Ω
Fs	20 Hz
Qts	0.47
Qes	0.5
Qms	7.7
Vas	322 L
Sd	1164 cm²
Xmax	14.5 mm
Re	3.1 Ω
Bl	17.1 T·m
Mms	373.5 g
Pe	800 W
Sensitivity	93.2 dB

Alignment hint

EBP	40 · sealed
Sealed Vb (Qtc ≈ 0.71)	≈ 254.9 L

EBP < 50: favours a sealed (closed) alignment.

Rules of thumb from T/S parameters only. Verify against a real simulation before cutting wood.

Substitute candidates

Driver	Fs (Hz)	Qts	Vas (L)	Xmax (mm)	Sens (dB)	Fit	Notes	Compare
Dayton Audio RSS460HO-4	19.6 -0.4	0.387 -0.08	298 -24	12.8 -1.7	92.9 -0.3	close	Xmax 12.8 mm < 14.5 mm: lower excursion-limited SPL	+
FI Audio HT-3	21.3 +1.3	0.423 -0.05	235.9 -86.1	17 +2.5	92.9 -0.3	usable		+
CSS Audio Maelstrom 18 DVC by Exodus Audio	17.4 -2.6	0.376 -0.09	313 -9	14.7 +0.2	91.2 -2	usable		+
BMS 18N860	24 +4	0.372 -0.1	304 -18	15 +0.5	93.7 +0.5	usable	8 Ω vs 4 Ω: amp load changes	+
Magnat AGRESSOR 5000	24 +4	0.431 -0.04	324 +2	10.6 -3.9	95.3 +2.1	usable	Xmax 10.6 mm < 14.5 mm: lower excursion-limited SPL	+
Dayton Audio UMII18-22 ULTIMAX II DVC	22 +2	0.53 +0.06	248.2 -73.8	13.8 -0.7	90.7 -2.5	usable	8 Ω vs 4 Ω: amp load changes · Xmax 13.8 mm < 14.5 mm: lower excursion-limited SPL	+
BMS 18N862 vp	24.8 +4.8	0.383 -0.09	345.6 +23.6	16.2 +1.7	94.8 +1.6	usable	8 Ω vs 4 Ω: amp load changes	+
Dayton Audio UM18-22 18	19.5 -0.5	0.487 +0.02	216.8 -105.2	12.2 -2.3	89 -4.2	usable	8 Ω vs 4 Ω: amp load changes · Xmax 12.2 mm < 14.5 mm: lower excursion-limited SPL	+
TC Sounds LMS-ULTRA 5400	20.5 +0.5	0.325 -0.14	240.7 -81.3	16 +1.5	93.1 -0.1	usable		+
Stereo Integrity HT 18	17 -3	0.383 -0.09	411.9 +89.9	25.1 +10.6	92.5 -0.7	usable		+

Compare the closest 3 against the NS18-992-4A →

Ranked on parameter similarity only (Qts, Fs, Vas, Xmax, sensitivity). Same nominal size required. A hint, not a simulation, model the swap before cutting or buying.

Used in enclosures (0)

No enclosure in the catalog uses this driver yet.