SICA C 8/30 FA
Best box: 12.9 L bass reflex tuned to 64.3 Hz · F3 131.5 Hz
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Comparable 8.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the SICA C 8/30 FA 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
- The textbook alignment (8.6 L at 107.1 Hz) would need a 6.2 cm port; the recommendation is retuned to 12.9 L at 64.3 Hz so the port can be built.
- Xmax is not published, so the port size is an empirical estimate (area ≥ 12 in² per ft³ of net volume, minimum by driver size), not a displacement calculation. Check air velocity in Load Forge Studio.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 12.9 Liters |
| Tuning Frequency (Fb) | 64.3 Hz |
| F3 (-3 dB Cutoff) | 131.5 Hz |
| F6 / F10 Extension | 110.7 Hz / 86.6 Hz |
| Port Inner Diameter ESTIMATED | Ø 6.8 cm |
| Port Physical Length | 15.5 cm |
| First Pipe Resonance | 1106.0 Hz |
| Estimated MOL @ F3 | 109.3 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 1.01 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 1.428; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 10.8 Liters |
| System Q (Qtc) | 1.428 (above Butterworth: Qtc cannot fall below Qts (1.01)) |
| System Resonance (Fc) | 178.2 Hz |
| F3 (-3 dB Cutoff) | 138.1 Hz |
| F6 / F10 Extension | 118.7 Hz / 98.4 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 126.0 Hz |
| Total Q (Qts) | 1.01 |
| Electrical Q (Qes) | 1.087 |
| Mechanical Q (Qms) | 14.22 |
| Equivalent Volume (Vas) | 10.8 Liters |
| Diaphragm Area (Sd) | 213.8 cm² |
| DC Resistance (Re) | 6.2 Ω |
| Efficiency Bandwidth Product (EBP) | 115.9 |
| Linear Excursion (Xmax) | N/A mm |
| Thermal Power (Pe) | 30.0 W |
| Nominal Diameter | 8.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for SICA C 8/30 FA?
Load Forge's calculated alignment puts SICA C 8/30 FA in a 12.9 liter vented enclosure tuned to 64.3 Hz, reaching an F3 cutoff of approximately 131.5 Hz.
Can SICA C 8/30 FA be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 10.8 liters with a Qtc of 1.428 (above Butterworth: Qtc cannot fall below Qts (1.01)), the system exhibits an F3 of 138.1 Hz.
What port dimensions should be used for SICA C 8/30 FA to avoid port chuffing?
Xmax is not published for SICA C 8/30 FA, so the port is an empirical estimate: a 6.8 cm diameter with a length of 15.5 cm (area at least 12 in² per ft³ of net volume). Check the air velocity at your power level in Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
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