Audiobahn ALUM8P

8″ subwoofer · 350 W RMS

28.3 HzFs, resonance

0.42Qts

0.92 ft³Vas

0.31″Xmax

350 WRMS

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, 350 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

0.35 ft³ (10 L)

Net volume

Bass character (Qtc)	Tight and punchy · 0.79
Fc	54 Hz
F3 (−3 dB, no cabin gain)	51 Hz
Example box (outside)	10 1/4″ × 10 1/4″ × 10 1/16″

Open sealed box in designer

Ported

deeper, louder

0.74 ft³ (21 L)

Net volume

Tuning (Fb)	39 Hz
Port	round port Ø3″, 14 1/2″ long
Port velocity at 350 W	127 ft/s
F3 (−3 dB, no cabin gain)	35 Hz
Example box (outside)	20 9/16″ × 15 3/4″ × 6 7/8″

At 350 W this example’s port will be noisy: air speed 127 ft/s, while the limit is 82 ft/s. It stays quiet up to about 140 W. Full power needs a port of at least 10.9 in², which means a bigger box than this example — size it in the designer.

Open ported box in designer

Deeper: 1.13 ft³ (32 L) tuned to 29 Hz, 31 1/2″ × 15 3/4″ × 8″ 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	8″
Voice coils	—
RMS power	350 W
Fs	28.3 Hz
Qts	0.42
Qes	0.46
Qms	4.7
Vas	0.92 ft³

Re	5.8 Ω
Sd	38.8 in²
Xmax	0.31″
Vd	12.2 in³ calc.
Mms	108 g calc.
BL	15.5 T·m calc.
EBP	62 — sealed or ported calc.
Sensitivity, 1 W / 1 m	83.1 dB calc.

Mounting dimensions

Cutout diameter	7 1/4″
Mounting depth	4 3/8″
Overall diameter	8 1/2″

“≈” 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/20060317162127/http://www.audiobahn.com/Audiobahn06/images/t

Other Audiobahn 8″ models

Similar 8″ subwoofers from other brands

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

Audison Prima APS 8 D (DVC 4+4 ohm) 0.35 ft³ sealed · 0.71 ft³ ported
STX W.20.300.2x2.MC 0.32 ft³ sealed · 0.74 ft³ ported
Audison Prima APS 8 R (SVC 4 ohm, reflex) 0.32 ft³ sealed · 1.09 ft³ ported
Ground Zero GZIW 200 (4 Ohm) 0.35 ft³ sealed · 0.67 ft³ ported
Dayton Audio DCS205-4 0.32 ft³ sealed · 1.02 ft³ ported
STX W.20.300.2x4.MC 0.35 ft³ sealed · 0.71 ft³ ported

FAQ

What box does the Audiobahn ALUM8P need?

Recommended net volume: 0.35 ft³ sealed, 0.74 ft³ ported tuned to 39 Hz — for one sub in a sedan at 350 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the Audiobahn ALUM8P Thiele/Small specs?

Fs 28.3 Hz, Qts 0.42, Vas 0.92 ft³, Xmax 0.31″, Sd 38.8 in².

What is the Audiobahn ALUM8P mounting depth?

Mounting depth is 4 3/8″, cutout diameter 7 1/4″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Audiobahn ALUM8P handle and how do I wire it?

RMS power rating: 350 W. Wiring for several subs and amp power — in the wiring calculator.