Ascendant Audio Mayhem 18 D2

18″ subwoofer · dual 2 Ω · 4,500 W RMS

Fs 35.1 HzQts 0.48Vas 2.34 ft³Xmax 1.42″

Recommended box

For a sedan, one sub, 4,500 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 volume1.70 ft³ (48 L)
Qtc0.73
Fc54 Hz
F3 (−3 dB, no cabin gain)55 Hz
Example box (outside)19 11/16″ × 19 11/16″ × 11 11/16″
Open sealed box in designer

Ported

Net volume4.17 ft³ (118 L)
Tuning (Fb)32 Hz
Portround port Ø5″, 8 5/8″ long
Port velocity at 4,500 W369 ft/s
F3 (−3 dB, no cabin gain)29 Hz
Example box (outside)31 1/2″ × 20 1/2″ × 15 1/4″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs35.1 Hz
Qts0.48
Qes0.52
Qms5.72
Vas2.34 ft³
Re (one coil)1.61 Ω
Sd187.6 in²
Xmax1.42″
Vd265.8 in³ calc.
Mms645 g calc.
BL21 T·m calc.
EBP68 — sealed or ported calc.
Sensitivity, 1 W / 1 m89.4 dB calc.

General

Size18″
Voice coilsdual 2 Ω
RMS power4,500 W

Mounting dimensions

Ø≈ 17 11/16″cutout ≈ Ø16 9/16″mounting depth ≈ 8 1/4″magnet Ø≈ 10 3/4″
Cutout diameter≈ 16 9/16″
Mounting depth≈ 8 1/4″

Judging by its value, the published Re is for both coils in series — converted to per coil.

“≈” 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 Ascendant Audio 18″ models