Rockford Fosgate R2D4-12

12" · 8 Ω · 250 W · 88.9 dB · datasheet ↗

Thiele-Small parameters

Nominal size	12"
Impedance	8 Ω
Fs	34.9 Hz
Qts	0.605
Qes	0.66
Qms	7.33
Vas	68.8 L
Sd	539.1 cm²
Xmax	6.5 mm
Re	7.17 Ω
Bl	17.1 T·m
Mms	123.1 g
Pe	250 W
Sensitivity	88.9 dB

Alignment hint

EBP	53 · flexible
Sealed Vb (Qtc ≈ 0.71)	≈ 188 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
Hertz Audio ES F30.5	38 +3.1	0.6 -0.01	60 -8.8	6 -0.5	88.6 -0.3	close	4 Ω vs 8 Ω: amp load changes · Xmax 6 mm < 6.5 mm: lower excursion-limited SPL	+
MTX Audio T5512-04	29.3 -5.6	0.583 -0.02	66.9 -1.9	7.3 +0.8	89.8 +0.9	close	4 Ω vs 8 Ω: amp load changes	+
MTX Audio XT12-04	33 -1.9	0.56 -0.04	66 -2.8	6.5 =	91.7 +2.8	close	4 Ω vs 8 Ω: amp load changes	+
MTX Audio RTS12-04	33.5 -1.4	0.631 +0.03	58.4 -10.4	5.8 -0.7	89.5 +0.6	close	4 Ω vs 8 Ω: amp load changes · Xmax 5.8 mm < 6.5 mm: lower excursion-limited SPL	+
Alpine SWS-1241	30 -4.9	0.563 -0.04	65 -3.8	6.7 +0.2	90.1 +1.2	close	4 Ω vs 8 Ω: amp load changes	+
JBL STAGE 1210	31.7 -3.2	0.55 -0.05	64.6 -4.2	6.6 +0.1	90.8 +1.9	close	4 Ω vs 8 Ω: amp load changes	+
Peerless SBS-300F38CP01-04	36 +1.1	0.611 +0.01	55.8 -13	5.9 -0.6	90.9 +2	close	4 Ω vs 8 Ω: amp load changes · Xmax 5.9 mm < 6.5 mm: lower excursion-limited SPL	+
Wavecor SW310WA01	28.5 -6.4	0.603 =	65.5 -3.3	7.6 +1.1	86.8 -2.1	close		+
JBL S2-1224	32.4 -2.5	0.581 -0.02	59.7 -9.1	5.3 -1.2	89.1 +0.2	close	Xmax 5.3 mm < 6.5 mm: lower excursion-limited SPL	+
Rockford Fosgate R2SD4-12	30.3 -4.6	0.653 +0.05	65.4 -3.4	6.9 +0.4	86.7 -2.2	close		+

Compare the closest 3 against the R2D4-12 →

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.