Fi Audio Xv5 15 D2
15″ subwoofer · dual 2 Ω · 1,500 W RMS
The Fi Audio Xv5 15 D2 is a 15″ subwoofer. With Qts 0.39 and EBP 75 it works both sealed and ported: sealed is tighter and smaller, ported is deeper and louder. Long excursion (Xmax 1.14″) — built for loud music and high power.
| Source | ficaraudio.com · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | complete |
| Mounting dimensions | 3 of 4 — missing: magnet diameter; the designer will use an estimate |
Recommended box
For a sedan, one sub, 1,500 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
smaller, tighter| Bass character (Qtc) | Flat and accurate · 0.65 |
|---|---|
| Fc | 53 Hz |
| F3 (−3 dB, no cabin gain) | 61 Hz |
| Example box (outside) | 17 5/16″ × 17 5/16″ × 10 13/16″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 3 15/16 × 16 11/16″, 36 3/4″ long |
| Port velocity at 1,500 W | 64 ft/s |
| F3 (−3 dB, no cabin gain) | 31 Hz |
| Example box (outside) | 31 1/2″ × 18 1/8″ × 19 1/2″ |
Deeper: 2.26 ft³ (64 L) tuned to 34 Hz, 31 1/2″ × 18 1/8″ × 15″ outside — a bigger box with flatter deep bass. Open in the calculator
Projects with this subwoofer
Boxes that users designed and published: plans, cut sheet and response graph.
Thiele/Small parameters
| Size | 15″ |
|---|---|
| Voice coils | dual 2 Ω |
| RMS power | 1,500 W |
| Fs | 31.7 Hz |
| Qts | 0.39 |
| Qes | 0.422 |
| Qms | 5.2 |
| Vas | 2.18 ft³ |
| Re (one coil) | 1.89 Ω |
|---|---|
| Sd | 117.8 in² |
| Xmax | 1.14″ |
| Vd | 134.5 in³ calc. |
| Mms | 335 g calc. |
| BL | 17.3 T·m calc. |
| EBP | 75 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 88.7 dB calc. |
Mounting dimensions
| Cutout diameter | 14″ |
|---|---|
| Mounting depth | 8 3/8″ |
| Overall diameter | 15 3/8″ |
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
Voice coil versions
The same sub with different voice coils: the parameters are nearly the same — pick by your amp and wiring.
| Model | Voice coils | Re | Qes | Vas | Sealed | Ported |
|---|---|---|---|---|---|---|
| Fi Audio Xv5 15 D1 | dual 1 Ω | 1.01 Ω | 0.481 | 2.29 ft³ | 1.20 ft³ | 1.87 ft³ · 34 Hz |
| Fi Audio Xv5 15 D2 | dual 2 Ω | 1.89 Ω | 0.422 | 2.18 ft³ | 1.20 ft³ | 3.50 ft³ · 34 Hz |
Other Fi Audio 15″ models
- Fi Audio Alpha v1 15 S1 15″ · 1 Ω
- Fi Audio Alpha v1 15 S2 15″ · 2 Ω
- Fi Audio Alpha v1 15 S4 15″ · 4 Ω
- Fi Audio Alpha v2 15 S2 15″ · 2 Ω
- Fi Audio Alpha v2 15 S4 15″ · 4 Ω
- Fi Audio BL-NEO 15 D1 15″ · dual 1 Ω
- Fi Audio BL-NEO 15 D2 15″ · dual 2 Ω
- Fi Audio BL15 D1 15″ · dual 1 Ω
- Fi Audio BL15 D2 15″ · dual 2 Ω
- Fi Audio BL15v3 D1 15″ · dual 1 Ω
- Fi Audio BL15v3 D2 15″ · dual 2 Ω
- Fi Audio BL15v3.1 D1 15″ · dual 1 Ω
Similar 15″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Deaf Bonce Apocalypse DB-SA305 D1 1.13 ft³ sealed · 1.98 ft³ ported
- ESX QXE15D2 (2x2 Ohm) 1.17 ft³ sealed · 3.78 ft³ ported
- Deaf Bonce Apocalypse DB-SA2715 D1 1.13 ft³ sealed · 1.98 ft³ ported
- Deaf Bonce Apocalypse DB-SA2715 D2 1.13 ft³ sealed · 1.98 ft³ ported
- Deaf Bonce Apocalypse DB-3515R D2 1.59 ft³ sealed · 3.67 ft³ ported
- Deaf Bonce Apocalypse DB-3515R D1 1.59 ft³ sealed · 3.67 ft³ ported
FAQ
What box does the Fi Audio Xv5 15 D2 need?
Recommended net volume: 1.20 ft³ sealed, 3.50 ft³ ported tuned to 34 Hz — for one sub in a sedan at 1,500 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Fi Audio Xv5 15 D2 Thiele/Small specs?
Fs 31.7 Hz, Qts 0.39, Vas 2.18 ft³, Xmax 1.14″, Sd 117.8 in².
What is the Fi Audio Xv5 15 D2 mounting depth?
Mounting depth is 8 3/8″, cutout diameter 14″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Fi Audio Xv5 15 D2 handle and how do I wire it?
RMS power rating: 1,500 W. Dual 2 Ω voice coils: series gives 4 Ω, parallel gives 1 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.
Is the Fi Audio Xv5 15 D2 better sealed or ported?
EBP 75: both work — sealed 1.20 ft³ is tighter and smaller, ported 3.50 ft³ tuned to 34 Hz is deeper and louder.
What port does the Fi Audio Xv5 15 D2 need?
For the 3.50 ft³ ported box tuned to 34 Hz: slot 3 15/16 × 16 11/16″, 36 3/4″ long, area 65.7 in²; or a round port Ø9 1/8″, ≈ 36 3/4″ long. Port air speed at 1,500 W: 64 ft/s.
What box do two Fi Audio Xv5 15 D2 subs need?
Two subs need twice the volume: 2.40 ft³ sealed, or 6.99 ft³ ported at the same 34 Hz tuning with twice the port area. One shared chamber or one per sub — whatever fits your vehicle.