Eminence ALPHA-8MRA
Best box: 0.8 L sealed · Fc 726.9 Hz · F3 565.7 Hz
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Comparable 8.0" Drivers
Drivers with similar piston area, resonance and Qts — useful alternatives when the Eminence ALPHA-8MRA 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
- Limited linear excursion (Xmax: 1.6 mm); set a high-pass subsonic filter at 25–30 Hz when driven with high power.
Textbook Bass Reflex — not recommended (14.3 dB bass hump)
PORT BUILDABLE| Net Box Volume (Vb) | 1.5 Liters |
| Tuning Frequency (Fb) | 436.9 Hz |
| F3 (-3 dB Cutoff) | 528.7 Hz |
| F6 / F10 Extension | 451.5 Hz / 331.6 Hz |
| Port Inner Diameter | Ø 12.5 cm |
| Port Physical Length | 3.9 cm |
| First Pipe Resonance | 4399.0 Hz |
| Estimated MOL @ F3 | 124.1 dB SPL |
Sealed (Acoustic Suspension) — compromise
SUITS INFINITE / OPEN BAFFLEWith Qts 1.42 a Butterworth (Qtc 0.707) box would be many times Vas. A box equal to Vas reaches Qtc 2.008; for a flat response this driver is better used on an infinite (IB) or open baffle.
| Net Box Volume (Vb) | 0.8 Liters |
| System Q (Qtc) | 2.008 (above Butterworth: Qtc cannot fall below Qts (1.42)) |
| System Resonance (Fc) | 726.9 Hz |
| F3 (-3 dB Cutoff) | 565.7 Hz |
| F6 / F10 Extension | 501.6 Hz / 428.1 Hz |
| Air Spring Linearity | High (Zero port compression) |
Thiele/Small Parameters
| Resonance (Fs) | 514.0 Hz |
| Total Q (Qts) | 1.42 |
| Electrical Q (Qes) | 2.079 |
| Mechanical Q (Qms) | 4.48 |
| Equivalent Volume (Vas) | 0.8 Liters |
| Diaphragm Area (Sd) | 205.9 cm² |
| DC Resistance (Re) | 7.32 Ω |
| Efficiency Bandwidth Product (EBP) | 247.2 |
| Linear Excursion (Xmax) | 1.6 mm |
| Thermal Power (Pe) | 125.0 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 Eminence ALPHA-8MRA?
A simple ported box is not recommended for Eminence ALPHA-8MRA: the textbook alignment (1.5 liters tuned to 436.9 Hz) needs a 3.9 cm port, and no nearby retune stays buildable without a bass hump. A sealed box, a passive radiator or a folded duct is the practical choice.
Can Eminence ALPHA-8MRA be used in a sealed box?
Yes. In a sealed (acoustic suspension) enclosure of 0.8 liters with a Qtc of 2.008 (above Butterworth: Qtc cannot fall below Qts (1.42)), the system exhibits an F3 of 565.7 Hz.
What port dimensions should be used for Eminence ALPHA-8MRA to avoid port chuffing?
A straight 12.5 cm port would need 3.9 cm of length, which does not fit a practical cabinet. Use a passive radiator or a folded/3D duct instead of a straight tube.
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