Rockford Fosgate P1S8-12

12" · 8 Ω · 250 W · 87.4 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	8 Ω
Fs	26 Hz
Qts	0.593
Qes	0.64
Qms	8
Vas	109 L
Sd	540 cm²
Xmax	9 mm
Re	6.8 Ω
Bl	15.6 T·m
Mms	140.5 g
Pe	250 W
Sensitivity	87.4 dB

Alignment hint

EBP	41 · sealed
Sealed Vb (Qtc ≈ 0.71)	≈ 258.4 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 P1S412	25 -1	0.537 -0.06	109 =	9 =	90.4 +3	close	4 Ω vs 8 Ω: amp load changes	+
JL Audio 12WX-4	27 +1	0.562 -0.03	94.5 -14.5	8.5 -0.5	90.5 +3.1	close	4 Ω vs 8 Ω: amp load changes · Xmax 8.5 mm < 9 mm: lower excursion-limited SPL	+
Rockford Fosgate P1S2-12	25 -1	0.55 -0.04	88.3 -20.7	9 =	85.1 -2.3	close	2 Ω vs 8 Ω: amp load changes	+
Rockford Fosgate P1S4-12	25 -1	0.55 -0.04	88.3 -20.7	9 =	85.1 -2.3	close	4 Ω vs 8 Ω: amp load changes	+
Focal 30A4	24.7 -1.3	0.671 +0.08	86.9 -22.1	8.5 -0.5	87.3 -0.1	usable	Xmax 8.5 mm < 9 mm: lower excursion-limited SPL	+
Focal 30A4 vp	24.7 -1.3	0.671 +0.08	86.9 -22.1	8.5 -0.5	87.3 -0.1	usable	Xmax 8.5 mm < 9 mm: lower excursion-limited SPL	+
Hertz Audio DS 30.3	29 +3	0.51 -0.08	94 -15	9 =	87.7 +0.3	usable	4 Ω vs 8 Ω: amp load changes	+
Dayton Audio UM12-22	24.9 -1.1	0.589 =	71.6 -37.4	12.5 +3.5	87.7 +0.3	usable	4 Ω vs 8 Ω: amp load changes	+
JL Audio 12W1V2-8	24.98 -1.02	0.458 -0.13	100.15 -8.85	9.5 +0.5	86.8 -0.6	usable		+
Rockford Fosgate P2D4-12	27 +1	0.581 -0.01	70.3 -38.7	10.1 +1.1	86.8 -0.6	usable		+

Compare the closest 3 against the P1S8-12 →

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.