SPL Dynamics V-12S

12″ subwoofer · 4 Ω · 300 W RMS

28 HzFs, resonance

0.34Qts

4.84 ft³Vas

0.28″Xmax

300 WRMS

Source	web.archive.org · manufacturer data
Checked against source	October 2026
Thiele/Small parameters	complete
Mounting dimensions	2 of 4 — missing: frame outer diameter, magnet diameter; the designer will use an estimate

Recommended box

For a sedan, one sub, 300 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

smaller, tighter

1.02 ft³ (29 L)

Net volume

Bass character (Qtc)	Tight and punchy · 0.80
Fc	67 Hz
F3 (−3 dB, no cabin gain)	64 Hz
Example box (outside)	14 3/16″ × 14 3/16″ × 13 7/16″

Open sealed box in designer

Ported

deeper, louder

2.37 ft³ (67 L)

Net volume

Tuning (Fb)	31 Hz
Port	slot 1 9/16 × 14 5/16″, 22 5/8″ long
Port velocity at 300 W	50 ft/s
F3 (−3 dB, no cabin gain)	38 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 12 15/16″

Open ported box in designer

Deeper: 3.11 ft³ (88 L) tuned to 35 Hz, 31 1/2″ × 15 3/4″ × 15 5/16″ outside — a bigger box with flatter deep bass. Open in the calculator

Where to buy Amazon

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

Thiele/Small parameters

Size	12″
Voice coils	4 Ω
RMS power	300 W
Fs	28 Hz
Qts	0.34
Qes	0.36
Qms	4.99
Vas	4.84 ft³

Re	3.7 Ω
Sd	80.5 in²
Xmax	0.28″
Vd	22.2 in³ calc.
Mms	90 g calc.
BL	12.8 T·m calc.
EBP	78 — sealed or ported calc.
Sensitivity, 1 W / 1 m	91.2 dB calc.

Mounting dimensions

Cutout diameter	10 7/8″
Mounting depth	5 1/4″

Cone area (Sd) calculated from Fs, Vas and Mms: 80.5 in².

“≈” 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

web.archive.org/web/20070718034135/http://www.spldynamics.fi:80/oldmodels/oldsub

Other SPL Dynamics 12″ models

SPL Dynamics PRO-12D2 MK3 12″ · dual 2 Ω
SPL Dynamics PRO-12D2 MK4 12″ · dual 2 Ω
SPL Dynamics PRO-12D4 MK3 12″ · dual 4 Ω
SPL Dynamics PRO-12D4 MK4 12″ · dual 4 Ω
SPL Dynamics PRO-300D2 12″ · dual 2 Ω
SPL Dynamics PRO-300D4 12″ · dual 4 Ω
SPL Dynamics SPL-300D1A 12″ · dual 1 Ω
SPL Dynamics SPL-300D2 12″ · dual 2 Ω
SPL Dynamics SW-300D2 12″ · dual 2 Ω
SPL Dynamics SW-300D4 12″ · dual 4 Ω
SPL Dynamics V-12S4 12″ · 4 Ω
SPL Dynamics V-300D2 12″ · dual 2 Ω

Similar 12″ subwoofers from other brands

Close in Fs, Qts and Vas — a box of similar volume will suit them.

Helix DB 12 Deep Blue (1x4 Ohm) 0.88 ft³ sealed · 2.33 ft³ ported
Magnat Shockwave 1200 0.71 ft³ sealed · 2.26 ft³ ported
Orion XtrPro 12D (2000) 0.88 ft³ sealed · 2.40 ft³ ported
Dayton Audio SD315A-88 1.13 ft³ sealed · 2.40 ft³ ported
Polk Audio EX12 (EX Series II) 0.74 ft³ sealed · 2.26 ft³ ported
Gladen M 12 (SVC 4 ohm) 1.09 ft³ sealed · 2.26 ft³ ported

FAQ

What box does the SPL Dynamics V-12S need?

Recommended net volume: 1.02 ft³ sealed, 2.37 ft³ ported tuned to 31 Hz — for one sub in a sedan at 300 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the SPL Dynamics V-12S Thiele/Small specs?

Fs 28 Hz, Qts 0.34, Vas 4.84 ft³, Xmax 0.28″, Sd 80.5 in².

What is the SPL Dynamics V-12S mounting depth?

Mounting depth is 5 1/4″, cutout diameter 10 7/8″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the SPL Dynamics V-12S handle and how do I wire it?

RMS power rating: 300 W. Wiring for several subs and amp power — in the wiring calculator.