Fi Audio SSDv4 15 D1
15″ subwoofer · dual 1 Ω · 1,500 W RMS · also as SSDv4 15 D2 (dual 2 Ω)
The Fi Audio SSDv4 15 D1 is a 15″ subwoofer. With Qts 0.42 and EBP 82 it works both sealed and ported: sealed is tighter and smaller, ported is deeper and louder. Long excursion (Xmax 1.10″) — built for loud music and high power.
| Source | web.archive.org · 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) | Dry and tight · 0.61 |
|---|---|
| Fc | 54 Hz |
| F3 (−3 dB, no cabin gain) | 66 Hz |
| Example box (outside) | 17 5/16″ × 17 5/16″ × 12 3/4″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 2 3/4 × 16 11/16″, 47 1/4″ long |
| Port velocity at 1,500 W | 63 ft/s |
| F3 (−3 dB, no cabin gain) | 34 Hz |
| Example box (outside) | 25 3/16″ × 18 1/8″ × 17 1/2″ |
Deeper: 2.40 ft³ (68 L) tuned to 35 Hz, 31 1/2″ × 18 1/8″ × 15 3/8″ 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 1 Ω |
| RMS power | 1,500 W |
| Fs | 37 Hz |
| Qts | 0.42 |
| Qes | 0.45 |
| Qms | 6.23 |
| Vas | 1.63 ft³ |
| Re (one coil) | 0.7 Ω |
|---|---|
| Sd | 125.6 in² |
| Xmax | 1.10″ |
| Vd | 138.4 in³ calc. |
| Mms | 372 g calc. |
| BL | 11.6 T·m calc. |
| EBP | 82 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 89.2 dB calc. |
Mounting dimensions
| Cutout diameter | 14 1/8″ |
|---|---|
| Mounting depth | 10 1/4″ |
| Overall diameter | 15 5/8″ |
“≈” 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 SSDv4 15 D1 | dual 1 Ω | 0.7 Ω | 0.45 | 1.63 ft³ | 1.48 ft³ | 2.01 ft³ · 34 Hz |
| Fi Audio SSDv4 15 D2 | dual 2 Ω | 1.4 Ω | 0.45 | 1.63 ft³ | 1.48 ft³ | 2.01 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.
- Kicx HeadShot Q315 (1+1) 1.32 ft³ sealed · 2.01 ft³ ported
- Gladen SPL 15 (DVC) 1.45 ft³ sealed · 2.05 ft³ ported
- Skar Audio VXF-15 D4 1.32 ft³ sealed · 3.25 ft³ ported
- Resilient Sounds Platinum 15 V2 D1 1.62 ft³ sealed · 1.98 ft³ ported
- Swat EXE-15D2 v.3 1.39 ft³ sealed · 1.98 ft³ ported
- Ground Zero GZPW 15 Limited (2x1 Ohm) 1.62 ft³ sealed · 3.67 ft³ ported
All 15″ subwoofers in our database →
FAQ
What box does the Fi Audio SSDv4 15 D1 need?
Recommended net volume: 1.48 ft³ sealed, 2.01 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 SSDv4 15 D1 Thiele/Small specs?
Fs 37 Hz, Qts 0.42, Vas 1.63 ft³, Xmax 1.10″, Sd 125.6 in².
What is the Fi Audio SSDv4 15 D1 mounting depth?
Mounting depth is 10 1/4″, cutout diameter 14 1/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Fi Audio SSDv4 15 D1 handle and how do I wire it?
RMS power rating: 1,500 W. Dual 1 Ω voice coils: series gives 2 Ω, parallel gives 0.5 Ω at the amp. Wiring for several subs and amp power — in the wiring calculator.
Is the Fi Audio SSDv4 15 D1 better sealed or ported?
EBP 82: both work — sealed 1.48 ft³ is tighter and smaller, ported 2.01 ft³ tuned to 34 Hz is deeper and louder.
What port does the Fi Audio SSDv4 15 D1 need?
For the 2.01 ft³ ported box tuned to 34 Hz: slot 2 3/4 × 16 11/16″, 47 1/4″ long, area 46 in²; or a round port Ø7 5/8″, ≈ 47 1/4″ long. Port air speed at 1,500 W: 63 ft/s.
What box do two Fi Audio SSDv4 15 D1 subs need?
Two subs need twice the volume: 2.97 ft³ sealed, or 4.03 ft³ ported at the same 34 Hz tuning with twice the port area. One shared chamber or one per sub — whatever fits your vehicle.