Focal SUB 30 KXE 30 cm
Best box: 75.0 L bass reflex tuned to 24.5 Hz · F3 24.4 Hz
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Comparable 12.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Focal SUB 30 KXE 30 cm 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 (72.8 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) | 75.0 Liters |
| Tuning Frequency (Fb) | 24.5 Hz |
| F3 (-3 dB Cutoff) | 24.4 Hz |
| F6 / F10 Extension | 21.1 Hz / 18.6 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 72.8 cm |
| First Pipe Resonance | 236.0 Hz |
| Estimated MOL @ F3 | 112.5 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 36.7 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 43.9 Hz |
| F3 (-3 dB Cutoff) | 47.5 Hz |
| F6 / F10 Extension | 35.9 Hz / 27.1 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 29.0 Hz |
| Total Q (Qts) | 0.46 |
| Electrical Q (Qes) | 0.498 |
| Mechanical Q (Qms) | 6.1 |
| Equivalent Volume (Vas) | 50.0 Liters |
| Diaphragm Area (Sd) | 502.0 cm² |
| DC Resistance (Re) | 6.4 Ω |
| Efficiency Bandwidth Product (EBP) | 58.3 |
| Linear Excursion (Xmax) | 22.5 mm |
| Thermal Power (Pe) | 800.0 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 Focal SUB 30 KXE 30 cm?
Load Forge's calculated alignment puts Focal SUB 30 KXE 30 cm in a 75.0 liter vented enclosure tuned to 24.5 Hz, reaching an F3 cutoff of approximately 24.4 Hz.
Can Focal SUB 30 KXE 30 cm be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 36.7 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 47.5 Hz.
What port dimensions should be used for Focal SUB 30 KXE 30 cm to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 12.5 cm with a length of 72.8 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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