Sky High Car Audio BMX-6.5 D1

6.5″ subwoofer · dual 1 Ω · 500 W RMS

57.3 HzFs, resonance

0.85Qts

0.07 ft³Vas

0.59″Xmax

500 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, 500 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

0.18 ft³ (5 L)

Net volume

Bass character (Qtc)	Boomy, with a bump · 1.00
Fc	67 Hz
F3 (−3 dB, no cabin gain)	54 Hz
Example box (outside)	9 1/16″ × 9 1/16″ × 7 3/16″

Open sealed box in designer

Ported

deeper, louder

0.35 ft³ (10 L)

Net volume

Tuning (Fb)	43 Hz
Port	slot 1 15/16 × 14 5/16″, 111 1/8″ long
Port velocity at 500 W	31 ft/s
F3 (−3 dB, no cabin gain)	36 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 11 1/16″

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: 0.64 ft³ (18 L) tuned to 39 Hz, 17 1/4″ × 15 3/4″ × 6 7/8″ 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	6.5″
Voice coils	dual 1 Ω
RMS power	500 W
Fs	57.3 Hz
Qts	0.85
Qes	0.98
Qms	6.28
Vas	0.07 ft³

Re (one coil)	0.95 Ω
Sd	20.5 in²
Xmax	0.59″
Vd	12.1 in³ calc.
Mms	101 g calc.
BL	5.9 T·m calc.
EBP	58 — sealed or ported calc.
Sensitivity, 1 W / 1 m	77.6 dB calc.

Mounting dimensions

Cutout diameter	6″
Mounting depth	4 7/16″
Overall diameter	7 1/16″

Cone area (Sd) calculated from Fs, Vas and Mms: 20.5 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

skyhighcaraudio.com/sky-high-car-audio-bmx-series-6-5-subwoofer/

Other Sky High Car Audio 6.5″ models

Sky High Car Audio BMX-6.5 D2 6.5″ · dual 2 Ω
Sky High Car Audio FE-6.5 D2 6.5″ · dual 2 Ω
Sky High Car Audio FE-6.5 D4 6.5″ · dual 4 Ω
Sky High Car Audio FMX-6.5 D1 6.5″ · dual 1 Ω
Sky High Car Audio FMX-6.5 D2 6.5″ · dual 2 Ω
Sky High Car Audio FXB-6.5 D2 6.5″ · dual 2 Ω
Sky High Car Audio FXB-6.5 D4 6.5″ · dual 4 Ω

Similar 6.5″ subwoofers from other brands

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

DC Audio M4 6.5 D4 0.19 ft³ sealed · 0.35 ft³ ported
Sundown Audio Xv2-6.5 S4 0.18 ft³ sealed · 0.35 ft³ ported
Ground Zero GZRW 6XSPL (2x2 Ohm) 0.21 ft³ sealed · 0.35 ft³ ported
CT Sounds TROPO-6-5 D4 0.21 ft³ sealed · 0.35 ft³ ported
DC Audio M4 6.5 D2 0.19 ft³ sealed · 0.35 ft³ ported
Skar Audio EVL-65 D4 0.18 ft³ sealed · 0.35 ft³ ported

FAQ

What box does the Sky High Car Audio BMX-6.5 D1 need?

Recommended net volume: 0.18 ft³ sealed, 0.35 ft³ ported tuned to 43 Hz — for one sub in a sedan at 500 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 BMX-6.5 D1 Thiele/Small specs?

Fs 57.3 Hz, Qts 0.85, Vas 0.07 ft³, Xmax 0.59″, Sd 20.5 in².

What is the Sky High Car Audio BMX-6.5 D1 mounting depth?

Mounting depth is 4 7/16″, cutout diameter 6″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Sky High Car Audio BMX-6.5 D1 handle and how do I wire it?

RMS power rating: 500 W. Dual 1 Ω voice coils: series gives 2 Ω, parallel gives 0.5 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.