Polk Audio DB1240

12" · 4 Ω · 360 W · 88.1 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	4 Ω
Fs	30 Hz
Qts	0.44
Qes	0.459
Qms	10.4
Vas	71.85 L
Sd	520 cm²
Xmax	7.5 mm
Re	3.5 Ω
Bl	14.7 T·m
Mms	150.5 g
Pe	360 W
Sensitivity	88.1 dB

Alignment hint

EBP	65 · flexible
Sealed Vb (Qtc ≈ 0.71)	≈ 45.4 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
Powerbass M-124	29.15 -0.85	0.41 -0.03	77.3 +5.45	9.5 +2	88 -0.1	close		+
Kenwood KFC-W3010	32 +2	0.42 -0.02	63.93 -7.92	8 +0.5	88.6 +0.5	close	200 W vs 360 W: lower power handling	+
Kenwood KFC-W3009	32 +2	0.42 -0.02	63.93 -7.92	8 +0.5	88.7 +0.6	close	200 W vs 360 W: lower power handling	+
Alpine SWA-12S4	30 =	0.49 +0.05	67.79 -4.06	10 +2.5	87.2 -0.9	close	250 W vs 360 W: lower power handling	+
Infinity PRIMUS 1270	29.7 -0.3	0.49 +0.05	75.7 +3.85	11.3 +3.8	87.3 -0.8	close		+
Focal P30F	28 -2	0.467 +0.03	70 -1.85	9.1 +1.6	90.1 +2	close		+
OmnesAudio SW12HEX	26.4 -3.6	0.453 +0.01	68.7 -3.15	7 -0.5	86.9 -1.2	close	8 Ω vs 4 Ω: amp load changes · 250 W vs 360 W: lower power handling · Xmax 7 mm < 7.5 mm: lower excursion-limited SPL	+
Magnat AD 300 Séries II	30 =	0.411 -0.03	72 +0.15	7.3 -0.2	92.6 +4.5	close	Xmax 7.3 mm < 7.5 mm: lower excursion-limited SPL	+
Infinity 1230W	27.3 -2.7	0.437 =	78.5 +6.65	7.9 +0.4	91 +2.9	close		+
Magnat AD300	30 =	0.411 -0.03	72 +0.15	7.3 -0.2	92.8 +4.7	close	Xmax 7.3 mm < 7.5 mm: lower excursion-limited SPL	+

Compare the closest 3 against the DB1240 →

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.