Focal 33KX

12" · 8 Ω · 400 W · 87.2 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	8 Ω
Fs	39 Hz
Qts	0.733
Qes	0.84
Qms	5.77
Vas	25 L
Sd	491 cm²
Xmax	5 mm
Re	4.2 Ω
Bl	16.6 T·m
Mms	225.1 g
Pe	400 W
Sensitivity	87.2 dB

Alignment hint

EBP	46 · sealed
Sealed Vb (Qtc ≈ 0.71)	Qts too high

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
Pioneer TS-W309D4	37.2 -1.8	0.811 +0.08	33.8 +8.8	5.7 +0.7	86.4 -0.8	usable		+
Pioneer TS-W310D4	37 -2	0.778 +0.05	37.4 +12.4	6.2 +1.2	87 -0.2	usable		+
Skar Audio EV-12 S2	43.1 +4.1	0.7 -0.03	36.7 +11.7	8.5 +3.5	87.6 +0.4	usable	2 Ω vs 8 Ω: amp load changes · 200 W vs 400 W: lower power handling	+
Skar Audio EV-12 S4	45.7 +6.7	0.71 -0.02	34.8 +9.8	8.5 +3.5	88 +0.8	usable	4 Ω vs 8 Ω: amp load changes · 200 W vs 400 W: lower power handling	+
Monacor RAPTOR 12	43 +4	0.624 -0.11	27.5 +2.5	8.5 +3.5	90.7 +3.5	usable	4 Ω vs 8 Ω: amp load changes	+
Pioneer TS-SW3001S2	36.8 -2.2	0.825 +0.09	18 -7	4.4 -0.6	89.3 +2.1	usable	2 Ω vs 8 Ω: amp load changes · Xmax 4.4 mm < 5 mm: lower excursion-limited SPL	+
Ground Zero GZIW 12XSPL-D2	32.5 -6.5	0.736 =	40.4 +15.4	7.6 +2.6	87.1 -0.1	usable		+
Pioneer TS-SW1241D(PREMIER)	33.1 -5.9	0.73 =	19.51 -5.49	6.35 +1.35	81.4 -5.8	usable	4 Ω vs 8 Ω: amp load changes	+
JL Audio 12TW1-2	35 -4	0.577 -0.16	28.54 +3.54	10 +5	85.07 -2.13	usable	2 Ω vs 8 Ω: amp load changes · 300 W vs 400 W: lower power handling	+
Pioneer TS-W311S4	42 +3	0.795 +0.06	37.5 +12.5	5.8 +0.8	91.4 +4.2	usable	4 Ω vs 8 Ω: amp load changes	+

Compare the closest 3 against the 33KX →

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.