18 Sound 8MB400

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

Thiele-Small parameters

Nominal size	8"
Impedance	8 Ω
Fs	64 Hz
Qts	0.38
Qes	0.43
Qms	3.23
Vas	23.9 L
Sd	227 cm²
Xmax	5.8 mm
Re	5 Ω
Bl	9.3 T·m
Mms	18 g
Pe	280 W
Sensitivity	95 dB

Alignment hint

EBP	149 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 9.7 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	66 +2	0.41 +0.03	24.53 +0.63	5.8 =	95 =	close	16 Ω vs 8 Ω: amp load changes	+
B&C 8MBX51	68 +4	0.38 =	22 -1.9	6 +0.2	97 +2	close	16 Ω vs 8 Ω: amp load changes · 200 W vs 280 W: lower power handling	+
B&C 8FMB51	68 +4	0.39 +0.01	20.5 -3.4	5.5 -0.3	96 +1	close	16 Ω vs 8 Ω: amp load changes · Xmax 5.5 mm < 5.8 mm: lower excursion-limited SPL	+
18 Sound 8MB500	74 +10	0.43 +0.05	21.5 -2.4	6 +0.2	95 =	close		+
18 Sound 8MB500	73 +9	0.36 -0.02	18.4 -5.5	6 +0.2	95 =	close	4 Ω vs 8 Ω: amp load changes	+
Eminence BETA-8A	65 +1	0.38 =	23.3 -0.6	3 -2.8	95.1 +0.1	usable	Xmax 3 mm < 5.8 mm: lower excursion-limited SPL	+
Beyma 8"G40	70 +6	0.36 -0.02	17 -6.9	6.5 +0.7	95 =	usable		+
Faital PRO 8PR200	58 -6	0.37 -0.01	16.9 -7	8.15 +2.35	95 =	usable	200 W vs 280 W: lower power handling	+
B&C 8MBX51	60 -4	0.29 -0.09	23 -0.9	6 +0.2	96.5 +1.5	usable	200 W vs 280 W: lower power handling	+
Beyma 8"P300Fe/N	53 -11	0.31 -0.07	24.8 +0.9	6 +0.2	94 -1	usable		+

Compare the closest 3 against the 8MB400 →

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.