Sealed 21.2376 L
Follow the original manufacturer construction instructions.
Alpine / SUBWOOFER
Alpine SWR-12D4 — specifications and enclosures
Alpine SWR-12D4: 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. T/S coil connection is not explicit in this manual revision; Re and Le are left unset for electrical simulation.
Manufacturer enclosure recommendations
Bass-reflex 39.0772 L
Tuning Fb: 35 Hz.
Manufacturer port: shape: slot, width: 317.5 mm, height: 25.4 mm, length: 482.6 mm, count: 1.
Follow the original manufacturer construction instructions.
Calculator parameters
| Fs | 28 Hz |
|---|---|
| Vas | 46 L |
| Qes | 0.52 |
| Qms | 6.04 |
| Re | Not provided / unverified |
| Sd | 479 cm² |
| Le | Not provided / unverified |
| One-way linear Xmax | 20 mm |
| Frame diameter | 32.0 cm |
| Mounting cutout | 27.5 cm |
| Mounting depth | 16.2 cm |
Additional manufacturer specifications
| Published Qts | 0.48 |
|---|
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.