EMS B12 MKII

12" · 8 Ω · 100 W · 98.3 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	8 Ω
Fs	30 Hz
Qts	0.174
Qes	0.179
Qms	5.657
Vas	227 L
Sd	515 cm²
Xmax	4.6 mm
Re	6.37 Ω
Bl	17.6 T·m
Mms	46.1 g
Pe	100 W
Sensitivity	98.3 dB

Alignment hint

EBP	168 · ported
Sealed Vb (Qtc ≈ 0.71)	≈ 14.6 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
EMS B12	31 +1	0.168 -0.01	227 =	4.4 -0.2	98.8 +0.5	close	Xmax 4.4 mm < 4.6 mm: lower excursion-limited SPL	+
Audax PR33S66	30 =	0.169 =	214.4 -12.6	3.8 -0.8	98.2 -0.1	close	Xmax 3.8 mm < 4.6 mm: lower excursion-limited SPL	+
Altec 414-8E	30.3 +0.3	0.195 +0.02	224 -3	4 -0.6	97.9 -0.4	close	Xmax 4 mm < 4.6 mm: lower excursion-limited SPL	+
Fluxmag 1201-LB	28.9 -1.1	0.163 -0.01	196.2 -30.8	4 -0.6	98.4 +0.1	close	Xmax 4 mm < 4.6 mm: lower excursion-limited SPL	+
Altec 414-8C	30.2 +0.2	0.204 +0.03	230.2 +3.2	4 -0.6	97.5 -0.8	close	Xmax 4 mm < 4.6 mm: lower excursion-limited SPL	+
Audax PR330M0 v2014	26 -4	0.203 +0.03	208 -19	4 -0.6	95.6 -2.7	usable	Xmax 4 mm < 4.6 mm: lower excursion-limited SPL	+
Altec 414 Z	32 +2	0.219 +0.05	263 +36	4 -0.6	96.2 -2.1	usable	16 Ω vs 8 Ω: amp load changes · Xmax 4 mm < 4.6 mm: lower excursion-limited SPL	+
Monacor SPH-300CTC vp série	30 =	0.194 +0.02	155.9 -71.1	5 +0.4	93.5 -4.8	usable	16 Ω vs 8 Ω: amp load changes	+
Monacor SP-330PAX	33 +3	0.238 +0.06	190 -37	4.5 -0.1	97.4 -0.9	usable	Xmax 4.5 mm < 4.6 mm: lower excursion-limited SPL	+
Focal AUDIOM 12VX	23.5 -6.5	0.202 +0.03	238 +11	6 +1.4	94.5 -3.8	usable		+

Compare the closest 3 against the B12 MKII →

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.