18 Sound 8NMB420

8" · 8 Ω · 280 W · 95 dB · datasheet ↗

Thiele-Small parameters

Nominal size	8"
Impedance	8 Ω
Fs	61 Hz
Qts	0.28
Qes	0.31
Qms	4
Vas	33 L
Sd	230 cm²
Xmax	5.8 mm
Re	5 Ω
Bl	10 T·m
Mms	14.9 g
Pe	280 W
Sensitivity	95 dB

Alignment hint

EBP	197 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 6.1 L

EBP > 100: favours a ported (bass-reflex) 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
18 Sound 8NMB420	59 -2	0.31 +0.03	31 -2	5.8 =	95 =	close	4 Ω vs 8 Ω: amp load changes	+
B&C 8MBX51	60 -1	0.29 +0.01	23 -10	6 +0.2	96.5 +1.5	usable	200 W vs 280 W: lower power handling	+
Beyma 8"P300Fe/N	53 -8	0.31 +0.03	24.8 -8.2	6 +0.2	94 -1	usable		+
B&C 8FMB51	67 +6	0.28 =	20.7 -12.3	5.5 -0.3	96.5 +1.5	usable	Xmax 5.5 mm < 5.8 mm: lower excursion-limited SPL	+
18 Sound 8NW650	62 +1	0.25 -0.03	18.99 -14.01	5.5 -0.3	95 =	usable	16 Ω vs 8 Ω: amp load changes · Xmax 5.5 mm < 5.8 mm: lower excursion-limited SPL	+
18 Sound 8MB400	64 +3	0.38 +0.1	23.9 -9.1	5.8 =	95 =	usable		+
Beyma 8WRS300	65 +4	0.28 =	15 -18	6 +0.2	95 =	usable		+
18 Sound 8NTLS2000	43 -18	0.24 -0.04	30 -3	7.4 +1.6	93.5 -1.5	usable	4 Ω vs 8 Ω: amp load changes	+
18 Sound 8NW650	63 +2	0.25 -0.03	17.8 -15.2	5.5 -0.3	96 +1	usable	Xmax 5.5 mm < 5.8 mm: lower excursion-limited SPL	+
Faital PRO 8PR210	65 +4	0.29 +0.01	15.4 -17.6	6.92 +1.12	95 =	usable	200 W vs 280 W: lower power handling	+

Compare the closest 3 against the 8NMB420 →

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.