Ciare CXPA-4 4" Neodymium Coaxial Driver
Best box: 1.9 L bass reflex tuned to 101.0 Hz · F3 91.6 Hz
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Comparable 4.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Ciare CXPA-4 4" Neodymium Coaxial Driver 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 (1.5 L at 168.3 Hz) would need a 10.3 cm port; the recommendation is retuned to 1.9 L at 101.0 Hz so the port can be built.
- Limited linear excursion (Xmax: 2.75 mm); set a high-pass subsonic filter at 25–30 Hz when driven with high power.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 1.9 Liters |
| Tuning Frequency (Fb) | 101.0 Hz |
| F3 (-3 dB Cutoff) | 91.6 Hz |
| F6 / F10 Extension | 85.8 Hz / 80.2 Hz |
| Port Inner Diameter | Ø 5.0 cm |
| Port Physical Length | 26.8 cm |
| First Pipe Resonance | 642.0 Hz |
| Estimated MOL @ F3 | 104.9 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 0.73 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 1.032; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 0.37 Liters |
| System Q (Qtc) | 1.032 (above Butterworth: Qtc cannot fall below Qts (0.73)) |
| System Resonance (Fc) | 280.0 Hz |
| F3 (-3 dB Cutoff) | 237.1 Hz |
| F6 / F10 Extension | 196.0 Hz / 157.2 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 198.0 Hz |
| Total Q (Qts) | 0.73 |
| Electrical Q (Qes) | 0.858 |
| Mechanical Q (Qms) | 4.9 |
| Equivalent Volume (Vas) | 0.4 Liters |
| Diaphragm Area (Sd) | 51.5 cm² |
| DC Resistance (Re) | 5.26 Ω |
| Efficiency Bandwidth Product (EBP) | 230.8 |
| Linear Excursion (Xmax) | 2.8 mm |
| Thermal Power (Pe) | 100.0 W |
| Nominal Diameter | 4.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Ciare CXPA-4 4" Neodymium Coaxial Driver?
Load Forge's calculated alignment puts Ciare CXPA-4 4" Neodymium Coaxial Driver in a 1.9 liter vented enclosure tuned to 101.0 Hz, reaching an F3 cutoff of approximately 91.6 Hz.
Can Ciare CXPA-4 4" Neodymium Coaxial Driver be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 0.37 liters with a Qtc of 1.032 (above Butterworth: Qtc cannot fall below Qts (0.73)), the system exhibits an F3 of 237.1 Hz.
What port dimensions should be used for Ciare CXPA-4 4" Neodymium Coaxial Driver to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 5.0 cm with a length of 26.8 cm is suggested; check the port air velocity at your drive level in the Load Forge Studio.
Shareable Acoustic Card for Forums & Social Media
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