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Powerful compact bookshelf speaker with a Folded Motion™ tweeter and Folded Motion Cascading Bass-Reflex Port for deeper bass response.  Voice-matched with MartinLogan ESL speakers. 



Folded Motion® Tweeters  

The signature Folded Motion tweeters utilize extremely low mass diaphragms that "squeeze" air, and require significantly less excursion than the typical 1-inch dome tweeter, which drastically minimizes distortion while providing a lightning fast response time.  The increased surface area also provides a wide, yet controlled sound dispersion to create a realistic and carefully etched sound stage.  



Engineered Curves  

Flexible installation options allow table top or on-wall installation of all four speakers. The Motion 4i bookshelf speakers can also mount upside down to facilitate placement high on a wall.  



Cascading Bass Reflex Port

MartinLogan engineers were faced with a daunting task - create a compact speaker with low-end bass reproduction found in speakers much, much larger.  After many sleepless night and a myriad of prototypes, they created the Cascading Bass Reflex Port.  This brilliant solution allows a long tuned port, which is folded over itself (think of a trombone's tuning arm) to be compacted and squeezed into the Motion 4i.  The result is amazingly detailed low bass that can play at high volumes with minimum distortion - all thanks to the elegantly simple cascading fold that slows down and controls the air motion of the bass waves. 

Martin Logan Motion 4i Speaker each

  • Frequency Response: 70-23,000 Hz ±3dB 


    Recommended Amplifier Power: 20-150 watts per channel 


    Horizontal Dispersion: 80°   


    Vertical Dispersion: 80°  


    Sensitivity: 90 dB/2.83 volts/ meter 


    Impedance: 4 Ohms Compatible with 4, 6, or 8 Ohm rated amplifiers  


    Crossover Frequency: 2,900 Hz  


    High Frequency Transducer: 1" × 1.4" (2.6cm × 3.6cm) Folded Motion Transducer with 5.25" × 1.75" (13.3cm × 4.4cm) diaphragm  


    Low Frequency Transducer: 4" (10.2cm) poly cone with stamped steel basket. Non-resonant asymmetrical chamber format.  Rigid structured dust cap to reduce cone break-up modes.  Folded bass reflex port.


    Components: Custom air core coil and low DCR steel laminate inductors. Polyester film capacitors in series and low DF electrolytic capacitors in parallel.  Overall system thermal/current protection.  


    Inputs: Push style with banana jacks 


    Dimension: 12.6" x 5.6" x 5.7" 


    Weight: 6 Lbs. 



    Specifications are subject to change without notice

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