Sky High Car Audio FXB-10 D4

10″ subwoofer · dual 4 Ω · 1,000 W RMS

37.7 HzFs, resonance

0.69Qts

0.29 ft³Vas

1.18″Xmax

1,000 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, 1,000 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

0.60 ft³ (17 L)

Net volume

Bass character (Qtc)	Tight and punchy · 0.84
Fc	46 Hz
F3 (−3 dB, no cabin gain)	41 Hz
Example box (outside)	12 5/8″ × 12 5/8″ × 10 5/8″

Open sealed box in designer

Ported

deeper, louder

0.81 ft³ (23 L)

Net volume

Tuning (Fb)	38 Hz
Port	slot 1 15/16 × 14 5/16″, 59 15/16″ long
Port velocity at 1,000 W	60 ft/s
F3 (−3 dB, no cabin gain)	31 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 9 11/16″

The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.

Open ported box in designer

Deeper: 1.52 ft³ (43 L) tuned to 29 Hz, 29 5/16″ × 15 3/4″ × 9 7/16″ 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	10″
Voice coils	dual 4 Ω
RMS power	1,000 W
Fs	37.7 Hz
Qts	0.69
Qes	0.77
Qms	6.66
Vas	0.29 ft³

Re (one coil)	3.2 Ω
Sd	50.8 in²
Xmax	1.18″
Vd	60 in³ calc.
Mms	327 g calc.
BL	17.9 T·m calc.
EBP	49 — suits sealed calc.
Sensitivity, 1 W / 1 m	79.6 dB calc.

Mounting dimensions

Cutout diameter	9 1/4″
Mounting depth	6 15/16″
Overall diameter	10 9/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 50.8 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

skyhighcaraudio.com/sky-high-car-audio-fxb-series-10-subwoofer/

Other Sky High Car Audio 10″ models

Sky High Car Audio BMX-10 D1 10″ · dual 1 Ω
Sky High Car Audio BMX-10 D2 10″ · dual 2 Ω
Sky High Car Audio FE-10 D2 10″ · dual 2 Ω
Sky High Car Audio FE-10 D4 10″ · dual 4 Ω
Sky High Car Audio FEX-10 D2 10″ · dual 2 Ω
Sky High Car Audio FEX-10 D4 10″ · dual 4 Ω
Sky High Car Audio FXB-10 D2 10″ · dual 2 Ω

Similar 10″ subwoofers from other brands

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

Sundown Audio M10 D1 0.79 ft³ sealed · 0.92 ft³ ported
Sundown Audio M10 D2 0.79 ft³ sealed · 0.92 ft³ ported
DC Audio Level 2 M4 10 D2 0.67 ft³ sealed · 0.81 ft³ ported
DC Audio Level 2 M4 10 D4 0.67 ft³ sealed · 0.81 ft³ ported
Crossfire C3 10Dv2 0.60 ft³ sealed · 0.88 ft³ ported
DC Audio Level 3 10 D1 0.78 ft³ sealed · 0.81 ft³ ported

FAQ

What box does the Sky High Car Audio FXB-10 D4 need?

Recommended net volume: 0.60 ft³ sealed, 0.81 ft³ ported tuned to 38 Hz — for one sub in a sedan at 1,000 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 FXB-10 D4 Thiele/Small specs?

Fs 37.7 Hz, Qts 0.69, Vas 0.29 ft³, Xmax 1.18″, Sd 50.8 in².

What is the Sky High Car Audio FXB-10 D4 mounting depth?

Mounting depth is 6 15/16″, cutout diameter 9 1/4″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Sky High Car Audio FXB-10 D4 handle and how do I wire it?

RMS power rating: 1,000 W. Dual 4 Ω voice coils: series gives 8 Ω, parallel gives 2 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.