Sealed 22.0871 L
Follow the original manufacturer construction instructions.
Alpine / SUBWOOFER
Alpine SWR-1242D — specifications and enclosures
Alpine SWR-1242D: T/S parameters, mounting dimensions and manufacturer enclosure recommendations. Read the original PDF and load the driver into the 3D designer.
Archived Type-R revision. Use the exact model suffix; values were transcribed from the manufacturer table and drawings. The manufacturer specifies series-connected voice coils for T/S; Re is the sum of both coil resistances. Le is the published 1 kHz value.
Manufacturer enclosure recommendations
Bass-reflex 36.8119 L
Tuning Fb: 36 Hz.
Manufacturer port: shape: slot, width: 304.8 mm, height: 31.75 mm, length: 577.85 mm, count: 1.
Follow the original manufacturer construction instructions.
Calculator parameters
| Fs | 29 Hz |
|---|---|
| Vas | 45 L |
| Qes | 0.5 |
| Qms | 7.89 |
| Re | 7.4 Ω |
| Sd | 480 cm² |
| Le | 3.7 mH |
| One-way linear Xmax | 18.2 mm |
| Frame diameter | 32.0 cm |
| Mounting cutout | 27.5 cm |
| Mounting depth | 19.5 cm |
Additional manufacturer specifications
| Published Qts | 0.47 |
|---|
Data is for one subwoofer. Manufacturer recommendations are separate from CarBoxLab calculations. Net air volume excludes the driver, port and bracing; design dimensions are external. Loading a recommendation transfers the verified volume and tuning; confirm port geometry and construction separately.
Source documentation
Manufacturer technical documentation
Original manufacturer documents are not translated. Data reviewed: 2026-10-31.