SICA 6.5 C 1.5 CP
Best box: 7.0 L sealed · Fc 89.8 Hz · F3 89.9 Hz
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Comparable 6.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the SICA 6.5 C 1.5 CP 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
- Straight vent would be 276.5 cm long: not physically buildable as a simple tube. Use a passive radiator, a folded slot port or model a 3D folded duct in Load Forge Studio.
Textbook Bass Reflex — not recommended
PORT NOT BUILDABLE| Net Box Volume (Vb) | 16.0 Liters |
| Tuning Frequency (Fb) | 49.8 Hz |
| F3 (-3 dB Cutoff) | 47.8 Hz |
| F6 / F10 Extension | 42.6 Hz / 37.6 Hz |
| Port Inner Diameter | Ø 22.2 cm |
| Port Physical Length | 276.5 cm |
| First Pipe Resonance | 62.0 Hz |
| Estimated MOL @ F3 | 106.1 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 7.0 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 89.8 Hz |
| F3 (-3 dB Cutoff) | 89.9 Hz |
| F6 / F10 Extension | 68.1 Hz / 51.4 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 50.8 Hz |
| Total Q (Qts) | 0.39 |
| Electrical Q (Qes) | 0.417 |
| Mechanical Q (Qms) | 6.09 |
| Equivalent Volume (Vas) | 15.9 Liters |
| Diaphragm Area (Sd) | 122.7 cm² |
| DC Resistance (Re) | 5.1 Ω |
| Efficiency Bandwidth Product (EBP) | 121.9 |
| Linear Excursion (Xmax) | 174.0 mm |
| Thermal Power (Pe) | 120.0 W |
| Nominal Diameter | 6.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for SICA 6.5 C 1.5 CP?
A simple ported box is not recommended for SICA 6.5 C 1.5 CP: the textbook alignment (16.0 liters tuned to 49.8 Hz) needs a 276.5 cm port, and no nearby retune stays buildable without a bass hump. A sealed box, a passive radiator or a folded duct is the practical choice.
Can SICA 6.5 C 1.5 CP be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 7.0 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 89.9 Hz.
What port dimensions should be used for SICA 6.5 C 1.5 CP to avoid port chuffing?
A straight 22.2 cm port would need 276.5 cm of length, which does not fit a practical cabinet. Use a passive radiator or a folded/3D duct instead of a straight tube.
Shareable Acoustic Card for Forums & Social Media
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