Guitar Bass Pro Audio Custom / OEM
 
ALPHA-8MRA    
SPECIFICATION  
Nominal Basket Diameter 8", 203.2mm
Nominal Impedance* 8 ohms
Power Rating  
Watts 125W
Music Program 250W
Resonance 514Hz
Usable Frequency Range 400Hz-4.8kHz
Sensitivity*** 100.9
Magnet Weight 20 oz.
Gap Height 0.25", 6.35mm
Voice Coil Diameter 1.5", 38.1mm
   
THIELE & SMALL PARAMETERS  
Resonant Frequency (fs) 514Hz

Download PDF Spec Sheet

 

 

Download PDF Cabinet Design

 
DC Resistance (Re) 7.32
Coil Inductance (Le) 0.34mH
Mechanical Q (Qms) 4.48
Electromagnetic Q (Qes) 2.08
Total Q (Qts) 1.42
Compliance Equivalent Volume (Vas) 0.8 liters / 0.03 cu.ft.
Peak Diaphragm Displacement Volume (Vd) 0cc
Mechanical Compliance of Suspension (Cms) 0.01mm/N
BL Product (BL) 8.9 T-M
Diaphram Mass inc. Airload (Mms) 6.9 grams
Efficiency Bandwidth Product (EBP) 247
Maximum Linear Excursion (Xmax) 1.6mm
Surface Area of Cone (Sd) 205.9 cm2  
Maximum Mechanical Limit (Xlim) 3.0mm  
     
MOUNTING INFORMATION    
Recommended Enclosure    
Sealed N/A  
Vented N/A  
Overall Diameter 8.22", 208.8mm  
Baffle Hole Diameter 7.19", 182.5mm  
Front Sealing Gasket Fitted as standard  
Rear Sealing Gasket Fitted as standard  
Mounting Holes Diameter 0.22", 5.5mm  
Mounting Holes B.C. D. 7.75", 196.9mm  
Depth 3.25", 83mm  
Net Weight 4.4 lbs., 2 kg  
Shipping Weight 5.1 lbs., 2.3 kg  
     
MATERIALS OF CONSTRUCTION    
Coil Construction Copper voice coil  
Coil Former Polyimide former  
Magnet Composition Ferrite magnet  
Core Details Vented core  
Basket Materials Pressed steel basket with closed back  
Cone Composition Paper Cone  
Cone Edge Composition Paper cone edge  
Dustcap Composition Solid composition paper dust cap  
     
FOOTNOTES    

*

Please consult www.eminence.com for specifications of models with alternative impedances.
** Multiple units exceed published rating evaluated under EIA 426A noise source and test standard while in a free-air, non-temperature controlled environment.
***

The average on axis output across the usable frequency range when applying 1W/1m into the nominal impedance, i.e. 2.83V/8Ω, 4V/16Ω.  Eminence response curves are measured under the following conditions:  All speakers are tested at 1W/1m using a variety of test set-ups for the appropriate impedance | LMS using 0.25" supplied microphone (software calibrated) mounted 1m from wall/baffle | 2ft x 2ft baffle is built into the wall with speaker mounted flush against a steel ring for minimum diffraction | Carver PM-120 amplifier | 2700ft3 chamber with fiberglass on all six surfaces (three with custom-made wedges).

**** BETA 8CX, 10CX, 12CX and Acoustinator™ CX2008 are coaxial speakers with tweeter sold separately. Published Usable frequency response obtained with APT50 high frequency driver attached.