Massive Audio GTX124H

12″ subwoofer · dual 4 Ω · 800 W RMS

Fs 36 HzQts 0.73Vas 0.83 ft³Xmax 0.59″
The published specs don’t add up:

Recommended box

For a sedan, one sub, 800 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 volume1.66 ft³ (47 L)
Qtc0.89
Fc44 Hz
F3 (−3 dB, no cabin gain)38 Hz
Example box (outside)13 3/4″ × 13 3/4″ × 21 3/8″
Open sealed box in designer

Ported

Net volume3.07 ft³ (87 L)
Tuning (Fb)27 Hz
Portslot 2 3/4 × 14 5/16″, 41 15/16″ long
Port velocity at 800 W64 ft/s
F3 (−3 dB, no cabin gain)23 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 18 13/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs36 Hz
Qts0.73
Qes0.82
Qms6.45
Vas0.83 ft³
Re (one coil)3.4 Ω
Sd79.1 in²
Xmax0.59″
Vd46.7 in³ calc.
Mms306 g calc.
BL17 T·m calc.
EBP44 — suits sealed calc.
Sensitivity, 1 W / 1 m83.3 dB calc.

General

Size12″
Voice coilsdual 4 Ω
RMS power800 W

Mounting dimensions

Ø12 5/16″cutout Ø10 13/16″mounting depth 6 11/16″magnet Ø≈ 7″
Cutout diameter10 13/16″
Mounting depth6 11/16″
Overall diameter12 5/16″

“≈” 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 Massive Audio 12″ models