Alpine RS-W12D2 (R-Series shallow)

12″ subwoofer · dual 2 Ω · 600 W RMS

Fs 28 HzQts 0.98Vas 1.48 ft³Xmax 0.79″

The published specs don’t add up:

Sd of 88.7 in² is unusual for a 12″ (typically 63.6–88.4 in²).

Recommended box

For a sedan, one sub, 600 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.

Sealed

Net volume	2.01 ft³ (57 L)
Qtc	1.29
Fc	37 Hz
F3 (−3 dB, no cabin gain)	27 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 9 15/16″

Open sealed box in designer

Ported

Net volume	3.43 ft³ (97 L)
Tuning (Fb)	28 Hz
Port	slot 2 3/16 × 14 5/16″, 26 5/16″ long
Port velocity at 600 W	65 ft/s
F3 (−3 dB, no cabin gain)	22 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 17 15/16″

Open ported box in designer

Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs	28 Hz
Qts	0.98
Qes	1.15
Qms	6.53
Vas	1.48 ft³
Re (one coil)	1.8 Ω
Sd	88.7 in²
Xmax	0.79″
Vd	69.8 in³ calc.
Mms	356 g calc.
BL	9.9 T·m calc.
EBP	24 — suits sealed calc.
Sensitivity, 1 W / 1 m	81 dB calc.

General

Size	12″
Voice coils	dual 2 Ω
RMS power	600 W

Mounting dimensions

Cutout diameter	11 5/8″
Mounting depth	3 1/4″
Overall diameter	13 9/16″

“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.

Data sources

Other Alpine 12″ models

Alpine R-W12D2 12″ · dual 2 Ω
Alpine R-W12D4 12″ · dual 4 Ω
Alpine R2-W12D2 12″ · dual 2 Ω
Alpine R2-W12D4 12″ · dual 4 Ω
Alpine RS-W12D4 (R-Series shallow) 12″ · dual 4 Ω
Alpine S-W12D4 12″ · dual 4 Ω
Alpine S2-W12D2 12″ · dual 2 Ω
Alpine S2-W12D4 12″ · dual 4 Ω
Alpine SWA-12S4 (Atom) 12″ · 4 Ω
Alpine SWE-1243E (Type-E) 12″ · 4 Ω
Alpine SWE-1244E (Type-E) 12″ · 4 Ω
Alpine SWG-1244 (Type-G) 12″ · 4 Ω