B&C Speakers 6HCX51
Best box: 4.7 L bass reflex tuned to 89.3 Hz · F3 85.7 Hz
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Comparable 6.5" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the B&C Speakers 6HCX51 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.
Recommended Bass Reflex (Vented)
PORT BUILDABLE| Net Box Volume (Vb) | 4.7 Liters |
| Tuning Frequency (Fb) | 89.3 Hz |
| F3 (-3 dB Cutoff) | 85.7 Hz |
| F6 / F10 Extension | 76.6 Hz / 67.7 Hz |
| Port Inner Diameter ESTIMATED | Ø 5.0 cm |
| Port Physical Length | 12.1 cm |
| First Pipe Resonance | 1418.0 Hz |
| Estimated MOL @ F3 | 109.5 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 2.0 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 161.7 Hz |
| F3 (-3 dB Cutoff) | 163.1 Hz |
| F6 / F10 Extension | 122.7 Hz / 92.1 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 89.0 Hz |
| Total Q (Qts) | 0.38 |
| Electrical Q (Qes) | 0.4 |
| Mechanical Q (Qms) | 7.5 |
| Equivalent Volume (Vas) | 5.0 Liters |
| Diaphragm Area (Sd) | 132.0 cm² |
| DC Resistance (Re) | 5.2 Ω |
| Efficiency Bandwidth Product (EBP) | 222.3 |
| Linear Excursion (Xmax) | N/A mm |
| Thermal Power (Pe) | 150.0 W |
| Nominal Diameter | 6.5" |
| 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 6HCX51?
Load Forge's calculated alignment puts B&C Speakers 6HCX51 in a 4.7 liter vented enclosure tuned to 89.3 Hz, reaching an F3 cutoff of approximately 85.7 Hz.
Can B&C Speakers 6HCX51 be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 2.0 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 163.1 Hz.
What port dimensions should be used for B&C Speakers 6HCX51 to avoid port chuffing?
Xmax is not published for B&C Speakers 6HCX51, so the port is an empirical estimate: a 5.0 cm diameter with a length of 12.1 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
Embed this design card on DIYAudio, AVSForum, Reddit, or Facebook. It shows the calculated F3, MOL (when the power rating is published) and box parameters.
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