Soundstream SPLX-124 ('07-'08)
12″ subwoofer · 4 Ω · 750 W RMS
| Source | web.archive.org · manufacturer data |
|---|---|
| Checked against source | October 2026 |
| Thiele/Small parameters | complete |
| Mounting dimensions | 2 of 4 — missing: frame outer diameter, magnet diameter; the designer will use an estimate |
- This sub has 4 voice coils — wiring options are calculated as for a single coil; check the final impedance against the spec sheet.
Recommended box
For a sedan, one sub, 750 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 · 0.60 |
|---|---|
| Fc | 55 Hz |
| F3 (−3 dB, no cabin gain) | 69 Hz |
| Example box (outside) | 14 3/16″ × 14 3/16″ × 9 11/16″ |
Ported
deeper, louder| Tuning (Fb) | 34 Hz |
|---|---|
| Port | slot 2 3/4 × 14 5/16″, 36 1/2″ long |
| Port velocity at 750 W | 62 ft/s |
| F3 (−3 dB, no cabin gain) | 30 Hz |
| Example box (outside) | 31 1/2″ × 15 3/4″ × 14 11/16″ |
Deeper: 1.41 ft³ (40 L) tuned to 33 Hz, 22 13/16″ × 15 3/4″ × 14 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 | 12″ |
|---|---|
| Voice coils | 4 Ω |
| RMS power | 750 W |
| Fs | 36.2 Hz |
| Qts | 0.39 |
| Qes | 0.419 |
| Qms | 6.78 |
| Vas | 0.90 ft³ |
| Re | 4.89 Ω |
|---|---|
| Sd | 74.4 in² |
| Xmax | 0.47″ |
| Vd | 35.1 in³ calc. |
| Mms | 249 g calc. |
| BL | 25.7 T·m calc. |
| EBP | 86 — sealed or ported calc. |
| Sensitivity, 1 W / 1 m | 86.6 dB calc. |
Mounting dimensions
| Cutout diameter | 11″ |
|---|---|
| Mounting depth | 7 1/8″ |
“≈” 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
Other Soundstream 12″ models
- Soundstream EXACT 12 12″ · 4 Ω
- Soundstream PCW-12 12″ · dual 4 Ω
- Soundstream PSW.124 12″ · 4 Ω
- Soundstream PWS-12 12″ · dual 4 Ω
- Soundstream PXW-12 12″ · dual 4 Ω
- Soundstream PXW-12/2 12″ · dual 2 Ω
- Soundstream R1-12 12″ · dual 4 Ω
- Soundstream R1-12L 12″ · dual 4 Ω
- Soundstream R3.12 12″ · dual 2 Ω
- Soundstream RBW-12 12″ · dual 4 Ω
- Soundstream RFW-12 12″ · dual 4 Ω
- Soundstream RW-12 12″ · dual 4 Ω
Similar 12″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- Crossfire C7 12D2 0.81 ft³ sealed · 1.24 ft³ ported
- Fi Audio Alpha v1 12 S1 0.67 ft³ sealed · 1.20 ft³ ported
- Fi Audio Alpha v1 12 S2 0.67 ft³ sealed · 1.20 ft³ ported
- Fi Audio Alpha v1 12 S4 0.67 ft³ sealed · 1.20 ft³ ported
- Kicx ZM-12 (2+2) 0.67 ft³ sealed · 1.17 ft³ ported
- Ascendant Audio Chaos 12 D1 0.67 ft³ sealed · 2.22 ft³ ported
FAQ
What box does the Soundstream SPLX-124 ('07-'08) need?
Recommended net volume: 0.67 ft³ sealed, 2.19 ft³ ported tuned to 34 Hz — for one sub in a sedan at 750 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Soundstream SPLX-124 ('07-'08) Thiele/Small specs?
Fs 36.2 Hz, Qts 0.39, Vas 0.90 ft³, Xmax 0.47″, Sd 74.4 in².
What is the Soundstream SPLX-124 ('07-'08) mounting depth?
Mounting depth is 7 1/8″, cutout diameter 11″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Soundstream SPLX-124 ('07-'08) handle and how do I wire it?
RMS power rating: 750 W. Wiring for several subs and amp power — in the wiring calculator.