Audiobahn AWT18X
18″ subwoofer · 4,000 W RMS
| 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, 4,000 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| Bass character (Qtc) | Tight and punchy · 0.80 |
|---|---|
| Fc | 31 Hz |
| F3 (−3 dB, no cabin gain) | 29 Hz |
| Example box (outside) | 31 1/2″ × 21 5/8″ × 12 9/16″ |
Ported
deeper, louder| Tuning (Fb) | 30 Hz |
|---|---|
| Port | slot 4 1/8 × 20 1/4″, 59 7/16″ long |
| Port velocity at 4,000 W | 68 ft/s |
| F3 (−3 dB, no cabin gain) | 26 Hz |
| Example box (outside) | 31 1/2″ × 21 5/8″ × 22″ |
Deeper: 6.99 ft³ (198 L) tuned to 25 Hz, 31 1/2″ × 21 5/8″ × 22 3/4″ 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 | 18″ |
|---|---|
| Voice coils | — |
| RMS power | 4,000 W |
| Fs | 20.4 Hz |
| Qts | 0.53 |
| Qes | 0.58 |
| Qms | 6.2 |
| Vas | 4.63 ft³ |
|---|---|
| Re | 1.95 Ω |
| Sd | ≈ 180.6 in² |
| Xmax | 0.91″ |
| EBP | 35 — suits sealed calc. |
| Sensitivity, 1 W / 1 m | 84.8 dB calc. |
Mounting dimensions
| Cutout diameter | 17 7/8″ |
|---|---|
| Mounting depth | 9 3/8″ |
| Overall diameter | 20 1/4″ |
“≈” 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/20060317162117/http://www.audiobahn.com/Audiobahn06/images/t
- web.archive.org/web/20050307032618/http://audiobahn.com/tech/2002/Sub%20Specs/Au
- web.archive.org/web/20041208210047/http://www.audiobahn.com/tech/2001/Audiobahn2
Other Audiobahn 18″ models
- Audiobahn AW1805Q 18″ · dual 2 Ω
- Audiobahn AW1805X 18″
Similar 18″ subwoofers from other brands
Close in Fs, Qts and Vas — a box of similar volume will suit them.
- DL Audio Phoenix Black Bass 18 (2+2) 4.13 ft³ sealed · 4.20 ft³ ported
- Fi Audio BTL4 18 D1 3.96 ft³ sealed · 4.27 ft³ ported
- Fi Audio BTL4 18 D2 3.71 ft³ sealed · 4.27 ft³ ported
- Fi Audio SP4 18 D2 4.27 ft³ sealed · 4.34 ft³ ported
- Fi Audio SP418 v2.1 D2 4.27 ft³ sealed · 4.34 ft³ ported
- Skar Audio ZVX-18v2 D2 3.43 ft³ sealed · 5.26 ft³ ported
FAQ
What box does the Audiobahn AWT18X need?
Recommended net volume: 3.64 ft³ sealed, 3.71 ft³ ported tuned to 30 Hz — for one sub in a sedan at 4,000 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.
What are the Audiobahn AWT18X Thiele/Small specs?
Fs 20.4 Hz, Qts 0.53, Vas 4.63 ft³, Xmax 0.91″.
What is the Audiobahn AWT18X mounting depth?
Mounting depth is 9 3/8″, cutout diameter 17 7/8″. The inside depth of the box must exceed the mounting depth by at least 1″.
How much power does the Audiobahn AWT18X handle and how do I wire it?
RMS power rating: 4,000 W. Wiring for several subs and amp power — in the wiring calculator.