Soundstream SPLX-154 ('07-'08)

15″ subwoofer · 4 Ω · 1,000 W RMS

40.4 HzFs, resonance

0.56Qts

1.75 ft³Vas

0.55″Xmax

1,000 WRMS

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

The published specs don’t add up:

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, 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

smaller, tighter

1.73 ft³ (49 L)

Net volume

Bass character (Qtc)	Tight and punchy · 0.80
Fc	57 Hz
F3 (−3 dB, no cabin gain)	54 Hz
Example box (outside)	17 5/16″ × 17 5/16″ × 14 7/16″

Open sealed box in designer

Ported

deeper, louder

2.12 ft³ (60 L)

Net volume

Tuning (Fb)	34 Hz
Port	slot 2 3/16 × 16 11/16″, 34 1/2″ long
Port velocity at 1,000 W	62 ft/s
F3 (−3 dB, no cabin gain)	35 Hz
Example box (outside)	24 9/16″ × 18 1/8″ × 15 3/4″

Open ported box in designer

Deeper: 5.12 ft³ (145 L) tuned to 31 Hz, 31 1/2″ × 18 1/8″ × 23 1/2″ outside — a bigger box with flatter deep bass. Open in the calculator

Where to buy Amazon

Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Size	15″
Voice coils	4 Ω
RMS power	1,000 W
Fs	40.4 Hz
Qts	0.56
Qes	0.607
Qms	8.15
Vas	1.75 ft³

Re	4.4 Ω
Sd	132.6 in²
Xmax	0.55″
Vd	73.1 in³ calc.
Mms	325 g calc.
BL	24.4 T·m calc.
EBP	66 — sealed or ported calc.
Sensitivity, 1 W / 1 m	89.3 dB calc.

Mounting dimensions

Cutout diameter	14 1/8″
Mounting depth	8 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

web.archive.org/web/20100104154501/http://soundstream.com/manuals/2009/SPLX_07_0

Other Soundstream 15″ models

Soundstream PCW-15 15″ · dual 4 Ω
Soundstream PWS-15 15″ · dual 4 Ω
Soundstream PXW-15 15″ · dual 4 Ω
Soundstream PXW-15/2 15″ · dual 2 Ω
Soundstream R1-15 15″ · dual 4 Ω
Soundstream R1-15L 15″ · dual 4 Ω
Soundstream R3.15 15″ · dual 2 Ω
Soundstream RBW-15 15″ · dual 4 Ω
Soundstream SPLX-152 ('07-'08) 15″ · dual 2 Ω
Soundstream SPLX-152 (2006) 15″ · dual 2 Ω
Soundstream SPLX-152HX 15″ · dual 2 Ω
Soundstream SPLX-154 (2006) 15″ · 4 Ω

Similar 15″ subwoofers from other brands

Close in Fs, Qts and Vas — a box of similar volume will suit them.

Ground Zero GZNW 15XSPL (2x1 Ohm) 1.80 ft³ sealed · 1.98 ft³ ported
Ground Zero GZHW 15SPL (2x2 Ohm) 2.44 ft³ sealed · 1.98 ft³ ported
Ground Zero GZUW 15XII (2x2 Ohm) 2.47 ft³ sealed · 1.98 ft³ ported
American Bass HD-1511 1.43 ft³ sealed · 3.25 ft³ ported
Ground Zero GZIW 15SPL (2x2 Ohm) 1.94 ft³ sealed · 2.22 ft³ ported
Sundown Audio Uv2-15 D4 1.45 ft³ sealed · 3.00 ft³ ported

FAQ

What box does the Soundstream SPLX-154 ('07-'08) need?

Recommended net volume: 1.73 ft³ sealed, 2.12 ft³ ported tuned to 34 Hz — for one sub in a sedan at 1,000 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the Soundstream SPLX-154 ('07-'08) Thiele/Small specs?

Fs 40.4 Hz, Qts 0.56, Vas 1.75 ft³, Xmax 0.55″, Sd 132.6 in².

What is the Soundstream SPLX-154 ('07-'08) mounting depth?

Mounting depth is 8 5/8″, 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 Soundstream SPLX-154 ('07-'08) handle and how do I wire it?

RMS power rating: 1,000 W. Wiring for several subs and amp power — in the wiring calculator.