MartinLogan Motion 4i

If you are having trouble with your MartinLogan Motion 4i, check out our troubleshooting guide to fix some common issues.

Released in 2010, the MartinLogan Motion 4i speaker was influenced by the clarity and detail of MartinLogan’s high-end electrostatic features but at a significantly reduced price. While considered a shelf speaker, the Motion 4i can be mounted in many different positions, including upside down, to enhance every consumer’s experience with the speaker. Its glossy piano-black finish and intricate design allows it to stand as a timeless element of any household.

The speaker’s capability to produce high frequencies with ease is due to the folded motion tweeter which allows air to be more compressed with the small mass of the tweeter, and the folded nature of it which amplifies the clarity and removes distortion from high frequency sounds. On the other hand, the low frequencies are amplified by the cascading bass reflex port which slows down air motion that is released from the speaker which diminishes any chance of low frequency distortion.

Joe Vojtko, MartinLogan's chief technologist, produced proprietary crossover networks that use "custom air core coil inductors, low DCR steel laminate inductors, and polyester film and low-DF electrolytic capacitors" that produces the best clarity for the Motion series. The voicing of the Vojtko crossover networks was "conducted in a space [...] of a real-world environment" which allows the speakers "to sound their best in real-world rooms."

Source: MartinLogan Motion 4i Website

This model of the MartinLogan speakers is defined by its model number, MO4IBL, and name, Motion 4i. There should be five indentations at the upper third of the face of the speaker when stood upright. It can also be identified by its signature curved back.

System Frequency Response:

• 70–23,000 Hz ±3 dB

Dispersion:

• 80° Horizontal
• 80° Vertical

Recommended Amplifier Power: 

• 20–150 Watts

Maximum Input Power: 

• 75 Watts

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 Driver: 

• 1” x 1.4” (2.6cm x 3.6cm) Folded Motion Transducer with 5.25” x 1.75” (13.3cm x 4.4cm) diaphragm

Low Frequency Driver: 

• 4” (10.2cm) paper cone with stamped steel basket
• Non-resonant asymmetrical chamber format
• Rigid structured dust cap to reduce cone break-up modes

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

Controls:

• Folded Bass Reflex Port

Binding Post Inputs: 

• Push style with banana jacks

Finish: 

• Gloss Black

Accessories (included): 

• Wall mount bracket

Weight: 

• 6 lbs. (2.72 kg)

Size (H x W x D):

• 12.6” x 5.6” x 5.7” (32 x 14.3 x 14.5 cm)

Source: Martin Logan 4i Website

MartinLogan Motion 4i Website

MartinLogan Motion 4i Online Manual

MartinLogan Motion 4i Amazon