B&C Speakers 15CX40
Best box: 215.6 L bass reflex tuned to 39.5 Hz · F3 36.6 Hz
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Comparable 15.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the B&C Speakers 15CX40 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
- 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.
- Large enclosure volume (215.6 L) requires extensive internal matrix bracing to prevent panel resonance.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 215.6 Liters |
| Tuning Frequency (Fb) | 39.5 Hz |
| F3 (-3 dB Cutoff) | 36.6 Hz |
| F6 / F10 Extension | 33.1 Hz / 29.5 Hz |
| Port Inner Diameter ESTIMATED | Ø 27.4 cm |
| Port Physical Length | 33.0 cm |
| First Pipe Resonance | 522.0 Hz |
| Estimated MOL @ F3 | 112.2 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 95.1 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 67.4 Hz |
| F3 (-3 dB Cutoff) | 67.6 Hz |
| F6 / F10 Extension | 51.2 Hz / 38.7 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 44.0 Hz |
| Total Q (Qts) | 0.43 |
| Electrical Q (Qes) | 0.459 |
| Mechanical Q (Qms) | 6.7 |
| Equivalent Volume (Vas) | 162.0 Liters |
| Diaphragm Area (Sd) | 855.0 cm² |
| DC Resistance (Re) | 5.1 Ω |
| Efficiency Bandwidth Product (EBP) | 95.8 |
| Linear Excursion (Xmax) | N/A mm |
| Thermal Power (Pe) | 80.0 W |
| Nominal Diameter | 15.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for B&C Speakers 15CX40?
Load Forge's calculated alignment puts B&C Speakers 15CX40 in a 215.6 liter vented enclosure tuned to 39.5 Hz, reaching an F3 cutoff of approximately 36.6 Hz.
Can B&C Speakers 15CX40 be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 95.1 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 67.6 Hz.
What port dimensions should be used for B&C Speakers 15CX40 to avoid port chuffing?
Xmax is not published for B&C Speakers 15CX40, so the port is an empirical estimate: a 27.4 cm diameter with a length of 33.0 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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