SICA ZJ04055
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 ZJ04055 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 / 86.8 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 | 118.8 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 ZJ04055?
Load Forge's calculated alignment puts SICA ZJ04055 in a 12.9 liter vented enclosure tuned to 64.3 Hz, reaching an F3 cutoff of approximately 131.5 Hz.
Can SICA ZJ04055 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 ZJ04055 to avoid port chuffing?
Xmax is not published for SICA ZJ04055, 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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