Focal Polyglass Sub P 30 DB
Best box: 113.7 L bass reflex tuned to 26.4 Hz · F3 24.6 Hz
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Comparable 12.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Focal Polyglass Sub P 30 DB does not fit your target box volume or tuning. Each entry links to its full enclosure design and Thiele/Small parameters.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 113.7 Liters |
| Tuning Frequency (Fb) | 26.4 Hz |
| F3 (-3 dB Cutoff) | 24.6 Hz |
| F6 / F10 Extension | 22.1 Hz / 19.7 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 37.5 cm |
| First Pipe Resonance | 459.0 Hz |
| Estimated MOL @ F3 | 114.4 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 50.6 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 47.1 Hz |
| F3 (-3 dB Cutoff) | 48.4 Hz |
| F6 / F10 Extension | 36.4 Hz / 27.5 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 30.0 Hz |
| Total Q (Qts) | 0.44 |
| Electrical Q (Qes) | 0.516 |
| Mechanical Q (Qms) | 3.0 |
| Equivalent Volume (Vas) | 80.0 Liters |
| Diaphragm Area (Sd) | 530.0 cm² |
| DC Resistance (Re) | 4.0 Ω |
| Efficiency Bandwidth Product (EBP) | 58.2 |
| Linear Excursion (Xmax) | 16.0 mm |
| Thermal Power (Pe) | 900.0 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 Polyglass Sub P 30 DB?
Load Forge's calculated alignment puts Focal Polyglass Sub P 30 DB in a 113.7 liter vented enclosure tuned to 26.4 Hz, reaching an F3 cutoff of approximately 24.6 Hz.
Can Focal Polyglass Sub P 30 DB be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 50.6 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 48.4 Hz.
What port dimensions should be used for Focal Polyglass Sub P 30 DB to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 12.5 cm with a length of 37.5 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
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