Rockford Fosgate P1S412

12" · 4 Ω · 250 W · 90.4 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	4 Ω
Fs	25 Hz
Qts	0.537
Qes	0.58
Qms	7.3
Vas	109 L
Sd	540 cm²
Xmax	9 mm
Re	3.4 Ω
Bl	11.8 T·m
Mms	152 g
Pe	250 W
Sensitivity	90.4 dB

Alignment hint

EBP	43 · sealed
Sealed Vb (Qtc ≈ 0.71)	≈ 148.5 L

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
Rockford Fosgate P112S4	25 =	0.52 -0.02	110 +1	7.3 -1.7	90.6 +0.2	close	150 W vs 250 W: lower power handling · Xmax 7.3 mm < 9 mm: lower excursion-limited SPL	+
JL Audio 12WX-4	27 +2	0.562 +0.03	94.5 -14.5	8.5 -0.5	90.5 +0.1	close	Xmax 8.5 mm < 9 mm: lower excursion-limited SPL	+
Ground Zero GZTW 30	25 =	0.44 -0.1	110 +1	11.2 +2.2	90.7 +0.3	close		+
Ground Zero GZTW 30T	25 =	0.443 -0.09	110 +1	11.9 +2.9	90.7 +0.3	close		+
Rockford Fosgate P1S8-12	26 +1	0.593 +0.06	109 =	9 =	87.4 -3	close	8 Ω vs 4 Ω: amp load changes	+
JBL GT3-12	28.2 +3.2	0.541 =	100.5 -8.5	8.2 -0.8	91.8 +1.4	close	Xmax 8.2 mm < 9 mm: lower excursion-limited SPL	+
Sony XS-L121P5S	22.6 -2.4	0.51 -0.03	102.1 -6.9	11.5 +2.5	89 -1.4	close		+
Peerless XXLS-P830845	27 +2	0.517 -0.02	119.5 +10.5	7.6 -1.4	89.8 -0.6	close	8 Ω vs 4 Ω: amp load changes · 175 W vs 250 W: lower power handling · Xmax 7.6 mm < 9 mm: lower excursion-limited SPL	+
Blaupunkt VCS 1200	23 -2	0.487 -0.05	102 -7	13 +4	89.9 -0.5	close		+
Thiel TSW 12.1 vp	20 -5	0.505 -0.03	112 +3	8.6 -0.4	89.9 -0.5	close	150 W vs 250 W: lower power handling · Xmax 8.6 mm < 9 mm: lower excursion-limited SPL	+

Compare the closest 3 against the P1S412 →

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.