Sky High Car Audio FEX-15 D2

15″ subwoofer · dual 2 Ω · 1,250 W RMS

30.5 HzFs, resonance

0.79Qts

3.81 ft³Vas

0.75″Xmax

1,250 WRMS

Source	skyhighcaraudio.com · manufacturer data
Checked against source	October 2026
Thiele/Small parameters	complete
Mounting dimensions	3 of 4 — missing: magnet diameter; the designer will use an estimate

Recommended box

For a sedan, one sub, 1,250 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

2.93 ft³ (83 L)

Net volume

Bass character (Qtc)	Boomy, with a bump · 1.19
Fc	46 Hz
F3 (−3 dB, no cabin gain)	35 Hz
Example box (outside)	31 1/2″ × 17 11/16″ × 12 3/8″

Open sealed box in designer

Ported

deeper, louder

3.04 ft³ (86 L)

Net volume

Tuning (Fb)	33 Hz
Port	slot 2 3/8 × 16 5/16″, 26″ long
Port velocity at 1,250 W	62 ft/s
F3 (−3 dB, no cabin gain)	32 Hz
Example box (outside)	31 1/2″ × 17 11/16″ × 15 1/4″

Open ported box in designer

Deeper: 4.98 ft³ (141 L) tuned to 35 Hz, 31 1/2″ × 17 11/16″ × 22 1/8″ 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	15″
Voice coils	dual 2 Ω
RMS power	1,250 W
Fs	30.5 Hz
Qts	0.79
Qes	0.873
Qms	8.03
Vas	3.81 ft³

Re (one coil)	2.09 Ω
Sd	128.6 in²
Xmax	0.75″
Vd	96.2 in³ calc.
Mms	247 g calc.
BL	10.6 T·m calc.
EBP	35 — suits sealed calc.
Sensitivity, 1 W / 1 m	87.4 dB calc.

Mounting dimensions

Cutout diameter	13 9/16″
Mounting depth	8 3/8″
Overall diameter	15 3/8″

“≈” 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

skyhighcaraudio.com/sky-high-car-audio-fex-series-15-subwoofer/

Other Sky High Car Audio 15″ models

Sky High Car Audio BMX-15 D1 15″ · dual 1 Ω
Sky High Car Audio BMX-15 D2 15″ · dual 2 Ω
Sky High Car Audio FE-15 D2 15″ · dual 2 Ω
Sky High Car Audio FE-15 D4 15″ · dual 4 Ω
Sky High Car Audio FEX-15 D4 15″ · dual 4 Ω
Sky High Car Audio FMX-15 D1 15″ · dual 1 Ω
Sky High Car Audio FMX-15 D2 15″ · dual 2 Ω
Sky High Car Audio FXB-15 D2 15″ · dual 2 Ω
Sky High Car Audio FXB-15 D4 15″ · dual 4 Ω
Sky High Car Audio FXXL-15 D1 15″ · dual 1 Ω
Sky High Car Audio FXXL-15 D2 15″ · dual 2 Ω

Similar 15″ subwoofers from other brands

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

Machete MS-15 D4 2.83 ft³ sealed · 3.00 ft³ ported
VM Audio EXW15 2.68 ft³ sealed · 2.79 ft³ ported
CT Sounds BIO-15 D2 2.90 ft³ sealed · 2.51 ft³ ported
Bomber Bicho Papão 800W 4+4 Ohm (SW15BPF800-4+4) 2.75 ft³ sealed · 3.21 ft³ ported
Quantum Audio Q3000/15D 2.75 ft³ sealed · 2.86 ft³ ported
Avatar SST-15 2.83 ft³ sealed · 3.18 ft³ ported

FAQ

What box does the Sky High Car Audio FEX-15 D2 need?

Recommended net volume: 2.93 ft³ sealed, 3.04 ft³ ported tuned to 33 Hz — for one sub in a sedan at 1,250 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the Sky High Car Audio FEX-15 D2 Thiele/Small specs?

Fs 30.5 Hz, Qts 0.79, Vas 3.81 ft³, Xmax 0.75″, Sd 128.6 in².

What is the Sky High Car Audio FEX-15 D2 mounting depth?

Mounting depth is 8 3/8″, cutout diameter 13 9/16″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Sky High Car Audio FEX-15 D2 handle and how do I wire it?

RMS power rating: 1,250 W. Dual 2 Ω voice coils: series gives 4 Ω, parallel gives 1 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.