Rockford Fosgate Power T215D4 (2004)

15″ subwoofer · dual 4 Ω · 1,000 W RMS

Fs 25 HzQts 0.44Vas 3.12 ft³Xmax 0.75″

Recommended box

For a sedan, one sub, 1,000 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 volume1.34 ft³ (38 L)
Qtc0.80
Fc46 Hz
F3 (−3 dB, no cabin gain)43 Hz
Example box (outside)16 15/16″ × 16 15/16″ × 12 5/16″
Open sealed box in designer

Ported

Net volume4.38 ft³ (124 L)
Tuning (Fb)25 Hz
Portslot 2 15/16 × 16 5/16″, 41 1/4″ long
Port velocity at 1,000 W64 ft/s
F3 (−3 dB, no cabin gain)23 Hz
Example box (outside)31 1/2″ × 17 11/16″ × 22 5/16″
Open ported box in designer
203040506080100150200606672788490HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs25 Hz
Qts0.44
Qes0.48
Qms4.98
Vas3.12 ft³
Re (one coil)3.6 Ω
Sd115.9 in²
Xmax0.75″
Vd86.7 in³ calc.
Mms363 g calc.
BL20.7 T·m calc.
EBP52 — sealed or ported calc.
Sensitivity, 1 W / 1 m86.6 dB calc.

General

Size15″
Voice coilsdual 4 Ω
RMS power1,000 W

Mounting dimensions

Ø15 3/4″cutout Ø13 13/16″mounting depth 9 7/8″magnet Ø≈ 9″
Cutout diameter13 13/16″
Mounting depth9 7/8″
Overall diameter15 3/4″

“≈” 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 Rockford Fosgate 15″ models