18 Sound 6NMB420

6.5" · 16 Ω · 200 W · 100 dB · datasheet ↗

Thiele-Small parameters

Nominal size	6.5"
Impedance	16 Ω
Fs	112 Hz
Qts	0.4
Qes	0.46
Qms	3.42
Vas	5.9 L
Sd	130 cm²
Xmax	3 mm
Re	10.6 Ω
Bl	9 T·m
Mms	8.5 g
Pe	200 W
Sensitivity	100 dB

Alignment hint

EBP	243 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 2.8 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 6NMB420	110 -2	0.33 -0.07	6.1 +0.2	3 =	100 =	close	8 Ω vs 16 Ω: amp load changes	+
B&C 6PEV13	126 +14	0.36 -0.04	6 +0.1	2.5 -0.5	99 -1	close	8 Ω vs 16 Ω: amp load changes · 120 W vs 200 W: lower power handling · Xmax 2.5 mm < 3 mm: lower excursion-limited SPL	+
Oberton 6M150	115.1 +3.1	0.422 +0.02	5.35 -0.55	2.25 -0.75	96 -4	usable	8 Ω vs 16 Ω: amp load changes · 150 W vs 200 W: lower power handling · Xmax 2.25 mm < 3 mm: lower excursion-limited SPL	+
18 Sound 6NMB900	100 -12	0.34 -0.06	6.65 +0.75	3 =	96 -4	usable		+
B&C 6MBX44	115 +3	0.35 -0.05	4 -1.9	3.5 +0.5	98 -2	usable		+
B&C 6CLA51	89 -23	0.41 +0.01	5.7 -0.2	5.5 +2.5	93.5 -6.5	usable		+
B&C 6MBX44	113 +1	0.31 -0.09	4.1 -1.8	3.5 +0.5	98 -2	usable	8 Ω vs 16 Ω: amp load changes	+
Oberton 6NM150	124 +12	0.377 -0.02	4 -1.9	2.25 -0.75	97 -3	usable	8 Ω vs 16 Ω: amp load changes · 150 W vs 200 W: lower power handling · Xmax 2.25 mm < 3 mm: lower excursion-limited SPL	+
Beyma 6G40Nd/N	100 -12	0.38 -0.02	3.7 -2.2	3 =	94 -6	usable	8 Ω vs 16 Ω: amp load changes	+
Beyma 6CMV2	90 -22	0.34 -0.06	6.5 +0.6	5.7 +2.7	94 -6	usable	8 Ω vs 16 Ω: amp load changes	+

Compare the closest 3 against the 6NMB420 →

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.