Eminence BETA 12CX
Best box: 181.4 L bass reflex tuned to 38.2 Hz · F3 35.6 Hz
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Comparable 12.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Eminence BETA 12CX 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
- Large enclosure volume (181.4 L) requires extensive internal matrix bracing to prevent panel resonance.
- Limited linear excursion (Xmax: 3.5 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) | 181.4 Liters |
| Tuning Frequency (Fb) | 38.2 Hz |
| F3 (-3 dB Cutoff) | 35.6 Hz |
| F6 / F10 Extension | 31.8 Hz / 28.3 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 5.0 cm |
| First Pipe Resonance | 3468.0 Hz |
| Estimated MOL @ F3 | 112.6 dB SPL |
Recommended Sealed (Acoustic Suspension)
MAX TRANSIENT DAMPING| Net Box Volume (Vb) | 103.4 Liters |
| System Q (Qtc) | 0.707 (Butterworth) |
| System Resonance (Fc) | 64.1 Hz |
| F3 (-3 dB Cutoff) | 65.4 Hz |
| F6 / F10 Extension | 49.3 Hz / 37.2 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 47.0 Hz |
| Total Q (Qts) | 0.48 |
| Electrical Q (Qes) | 0.525 |
| Mechanical Q (Qms) | 5.64 |
| Equivalent Volume (Vas) | 120.9 Liters |
| Diaphragm Area (Sd) | 538.9 cm² |
| DC Resistance (Re) | 5.42 Ω |
| Efficiency Bandwidth Product (EBP) | 89.6 |
| Linear Excursion (Xmax) | 3.5 mm |
| Thermal Power (Pe) | 250.0 W |
| Nominal Diameter | 12.0" |
| Catalog Source | Load Forge catalog (manufacturer datasheets and retailer listings) |
Frequently Asked Questions
What is the recommended ported (bass reflex) box volume for Eminence BETA 12CX?
Load Forge's calculated alignment puts Eminence BETA 12CX in a 181.4 liter vented enclosure tuned to 38.2 Hz, reaching an F3 cutoff of approximately 35.6 Hz.
Can Eminence BETA 12CX be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 103.4 liters with a Qtc of 0.707 (Butterworth), the system exhibits an F3 of 65.4 Hz.
What port dimensions should be used for Eminence BETA 12CX to avoid port chuffing?
Sized from cone displacement (Sd × Xmax), a minimum port diameter of 12.5 cm with a length of 5.0 cm is suggested; check the port air velocity at your drive level in the 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.
Not sure if BETA 12CX fits your physical space?
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