Focal 33K

12" · 4 Ω · 400 W · 93.5 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	4 Ω
Fs	38.4 Hz
Qts	0.415
Qes	0.44
Qms	7.19
Vas	51.1 L
Sd	551.5 cm²
Xmax	5.9 mm
Re	3.7 Ω
Bl	17.1 T·m
Mms	143.3 g
Pe	400 W
Sensitivity	93.5 dB

Alignment hint

EBP	87 · flexible
Sealed Vb (Qtc ≈ 0.71)	≈ 26.8 L

EBP 50-100: works in either a sealed or ported 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
Focal 30A1	37.4 -1	0.42 +0.01	53 +1.9	5.2 -0.7	93.9 +0.4	close	250 W vs 400 W: lower power handling · Xmax 5.2 mm < 5.9 mm: lower excursion-limited SPL	+
Focal ACCESS 30 A1	37.4 -1	0.42 +0.01	53 +1.9	5.2 -0.7	93.9 +0.4	close	250 W vs 400 W: lower power handling · Xmax 5.2 mm < 5.9 mm: lower excursion-limited SPL	+
Celestion FTR12-4080DL/4	35.3 -3.1	0.428 +0.01	51.4 +0.3	8 +2.1	92.5 -1	close		+
Pioneer TS-W306C	32.6 -5.8	0.414 =	55.6 +4.5	8.1 +2.2	92.8 -0.7	close		+
SICA 12 SR 3 PL v2018	36 -2.4	0.418 =	60.4 +9.3	7 +1.1	91.7 -1.8	close	8 Ω vs 4 Ω: amp load changes	+
18 Sound 12NTLS3500	41 +2.6	0.41 -0.01	65 +13.9	7.9 +2	93.5 =	close	8 Ω vs 4 Ω: amp load changes	+
Sica 12 SR 3 PL	36 -2.4	0.42 +0.01	60.4 +9.3	7 +1.1	91.8 -1.7	close	8 Ω vs 4 Ω: amp load changes	+
Gladen SQX12	36.7 -1.7	0.405 -0.01	40.9 -10.2	7 +1.1	92.6 -0.9	close		+
Sica 12 SR 3 CP	37 -1.4	0.4 -0.01	60.9 +9.8	8 +2.1	92.2 -1.3	close	8 Ω vs 4 Ω: amp load changes	+
SICA 12 SR 3 CP v2020	37.8 -0.6	0.402 -0.01	60.5 +9.4	5 -0.9	92.5 -1	close	8 Ω vs 4 Ω: amp load changes · Xmax 5 mm < 5.9 mm: lower excursion-limited SPL	+

Compare the closest 3 against the 33K →

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.