URAL AS-D15.3TD4 (4+4)

15″ subwoofer · dual 4 Ω · 600 W RMS

Fs 28.8 HzQts 0.68Vas 2.77 ft³

Recommended box

For a sedan, one sub, 600 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 volume2.83 ft³ (80 L)
Qtc0.96
Fc41 Hz
F3 (−3 dB, no cabin gain)34 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 11 3/4″
Open sealed box in designer

Ported

Net volume4.80 ft³ (136 L)
Tuning (Fb)29 Hz
Portslot 2 3/8 × 16 11/16″, 20 15/16″ long
Port velocity at 600 W64 ft/s
F3 (−3 dB, no cabin gain)25 Hz
Example box (outside)31 1/2″ × 18 1/8″ × 20 9/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs28.8 Hz
Qts0.68
Qes0.767
Qms6
Vas2.77 ft³
Re (one coil)≈ 3.4 Ω
Sd≈ 124 in²
Xmax≈ 0.39″
EBP38 — suits sealed calc.
Sensitivity, 1 W / 1 m85.9 dB calc.

General

Size15″
Voice coilsdual 4 Ω
RMS power600 W

Mounting dimensions

Ø≈ 15 3/8″cutout Ø14 3/16″mounting depth 7 3/8″magnet Ø≈ 9 3/16″
Cutout diameter14 3/16″
Mounting depth7 3/8″

Only Qts is published — Qms assumed to be 6 and Qes calculated (barely affects box design).

“≈” 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 URAL 15″ models