Fi Car Audio SW-ALPHA-12
Best box: 30.0 L bass reflex tuned to 33.9 Hz · F3 32.5 Hz
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Comparable 12.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Fi Car Audio SW-ALPHA-12 does not fit your target box volume or tuning. Each entry links to its full enclosure design and Thiele/Small parameters.
⚠️ Engineering Notice for Builders
- Port length (97.8 cm) exceeds a straight internal run; use an elbow bend, slotted vent or 3D folded duct to fit the enclosure.
Recommended Bass Reflex (Vented)
PORT NEEDS ELBOW / 3D| Net Box Volume (Vb) | 30.0 Liters |
| Tuning Frequency (Fb) | 33.9 Hz |
| F3 (-3 dB Cutoff) | 32.5 Hz |
| F6 / F10 Extension | 28.9 Hz / 25.6 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 97.8 cm |
| First Pipe Resonance | 176.0 Hz |
| Estimated MOL @ F3 | 125.5 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 13.1 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 61.7 Hz |
| F3 (-3 dB Cutoff) | 63.1 Hz |
| F6 / F10 Extension | 47.5 Hz / 35.8 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 36.2 Hz |
| Total Q (Qts) | 0.41 |
| Electrical Q (Qes) | 0.438 |
| Mechanical Q (Qms) | 6.43 |
| Equivalent Volume (Vas) | 25.9 Liters |
| Diaphragm Area (Sd) | 480.0 cm² |
| DC Resistance (Re) | 0.8 Ω |
| Efficiency Bandwidth Product (EBP) | 82.7 |
| Linear Excursion (Xmax) | 17.0 mm |
| Thermal Power (Pe) | N/A W |
| Nominal Diameter | 12.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Fi Car Audio SW-ALPHA-12?
Load Forge's calculated alignment puts Fi Car Audio SW-ALPHA-12 in a 30.0 liter vented enclosure tuned to 33.9 Hz, reaching an F3 cutoff of approximately 32.5 Hz.
Can Fi Car Audio SW-ALPHA-12 be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 13.1 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 63.1 Hz.
What port dimensions should be used for Fi Car Audio SW-ALPHA-12 to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 12.5 cm with a length of 97.8 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
Embed this design card on DIYAudio, AVSForum, Reddit, or Facebook. It shows the calculated F3, MOL (when the power rating is published) and box parameters.
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