Audiobahn AW831X

8″ subwoofer · 200 W RMS

36.7 HzFs, resonance

0.45Qts

0.57 ft³Vas

0.28″Xmax

200 WRMS

Source	web.archive.org · manufacturer data
Checked against source	October 2026
Thiele/Small parameters	not in the spec sheet: Sd — typical value for the size used
Mounting dimensions	3 of 4 — missing: magnet diameter; the designer will use an estimate

Recommended box

For a sedan, one sub, 200 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

0.32 ft³ (9 L)

Net volume

Bass character (Qtc)	Flat and accurate · 0.74
Fc	61 Hz
F3 (−3 dB, no cabin gain)	62 Hz
Example box (outside)	10 1/4″ × 10 1/4″ × 9 1/4″

Open sealed box in designer

Ported

deeper, louder

0.53 ft³ (15 L)

Net volume

Tuning (Fb)	40 Hz
Port	slot 1 15/16 × 14 5/16″, 84 9/16″ long
Port velocity at 200 W	19 ft/s
F3 (−3 dB, no cabin gain)	38 Hz
Example box (outside)	31 1/2″ × 15 3/4″ × 10 1/16″

The volume and tuning are the recommendation, but the port doesn’t fit this example box. Size the box and port in the designer.

Open ported box in designer

Deeper: 0.85 ft³ (24 L) tuned to 35 Hz, 31 1/2″ × 15 3/4″ × 6 3/4″ 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	200 W
Fs	36.7 Hz
Qts	0.45
Qes	0.51
Qms	3.6

Vas	0.57 ft³
Re	3.3 Ω
Sd	≈ 33.3 in²
Xmax	0.28″
EBP	72 — sealed or ported calc.
Sensitivity, 1 W / 1 m	83.9 dB calc.

Mounting dimensions

Cutout diameter	7″
Mounting depth	3 7/16″
Overall diameter	8 3/8″

“≈” 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/20041208210047/http://www.audiobahn.com/tech/2001/Audiobahn2

Other Audiobahn 8″ models

Similar 8″ subwoofers from other brands

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

ESX VXP822G (2x2 Ohm) 0.35 ft³ sealed · 0.60 ft³ ported
Massive Audio SUMMO 84 0.32 ft³ sealed · 0.53 ft³ ported
Audio System HX 08 SQ 0.32 ft³ sealed · 0.53 ft³ ported
JL Audio 8W3v3-4 0.28 ft³ sealed · 0.35 ft³ ported
Helix IK W8-DVC2 (2x2 Ohm) 0.32 ft³ sealed · 0.53 ft³ ported
Morel Ultimo 802 (SVC 2 ohm) 0.35 ft³ sealed · 0.60 ft³ ported

FAQ

What box does the Audiobahn AW831X need?

Recommended net volume: 0.32 ft³ sealed, 0.53 ft³ ported tuned to 40 Hz — for one sub in a sedan at 200 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the Audiobahn AW831X Thiele/Small specs?

Fs 36.7 Hz, Qts 0.45, Vas 0.57 ft³, Xmax 0.28″.

What is the Audiobahn AW831X mounting depth?

Mounting depth is 3 7/16″, cutout diameter 7″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Audiobahn AW831X handle and how do I wire it?

RMS power rating: 200 W. Wiring for several subs and amp power — in the wiring calculator.