Earthquake DBXI-12D

12″ subwoofer · dual 4 Ω · 500 W RMS

Fs 24 HzQts 0.41Vas 1.64 ft³
The published specs don’t add up:

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

Net volume0.71 ft³ (20 L)
Qtc0.75
Fc44 Hz
F3 (−3 dB, no cabin gain)44 Hz
Example box (outside)14 9/16″ × 14 9/16″ × 9 9/16″
Open sealed box in designer

Ported

Net volume1.91 ft³ (54 L)
Tuning (Fb)25 Hz
Portslot 1 9/16 × 14 5/16″, 46 11/16″ long
Port velocity at 500 W62 ft/s
F3 (−3 dB, no cabin gain)24 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 12 7/8″
Open ported box in designer
2030405060801001502006066727884HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs24 Hz
Qts0.41
Qes0.45
Qms4.7
Vas1.64 ft³
Re (one coil)4.8 Ω
Sd≈ 76 in²
Xmax≈ 0.39″
EBP53 — sealed or ported calc.
Sensitivity, 1 W / 1 m83.5 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power500 W

Mounting dimensions

Ø12 13/16″cutout ≈ Ø11 9/16″mounting depth 6 5/8″magnet Ø≈ 7 1/2″
Cutout diameter≈ 11 9/16″
Mounting depth6 5/8″
Overall diameter12 13/16″

“≈” 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 Earthquake 12″ models