The high-performance Motion 15i bookshelf speaker features a Folded Motion® tweeter, a 5.25-inch aluminum cone woofer with a rear-firing bass port, and a proprietary Vojtko crossover network to deliver refined sound with stunning dynamic range and jaw-dropping clarity. Motion 15i delivers the classic broad soundstage of the Motion Series from a newly designed enclosure enhanced by the slightest of modifications, including the drive-stabilizing dust cap design and stiffened motor suspension. The speaker’s cabinet sports a reinforced baffle and a fabric grille. Available in three stylish finishes: gloss black, matte white, and red walnut.

At a Glance

Model: MartinLogan Motion 15i
Sold as: Pair (price is per pair)
Available Finishes: Gloss Black, Matte White, Red Walnut
Frequency Response: 60–25,000 Hz ±3dB
Recommended Amplifier Power: 20—200 watts per channel
Horizontal Dispersion: 80°
Vertical Dispersion: 80°
Sensitivity: 92 dB/2.83 volts/meter
Impedance: 5 Ohms Compatible with 4, 6, or 8 Ohm rated amplifiers.

Key Features

Motion 15i Bookshelf Speakers
The high-performance Motion 15i bookshelf speaker features a Folded Motion® tweeter, a 5.25-inch aluminum cone woofer with a rear-firing bass port, and a proprietary Vojtko crossover network to deliver refined sound with stunning dynamic range and jaw-dropping clarity. Motion 15i delivers the classic broad soundstage of the Motion Series from a newly designed enclosure enhanced by the slightest of modifications, including the drive-stabilizing dust cap design and stiffened motor suspension. The speaker’s cabinet sports a reinforced baffle and a fabric grille. Available in three stylish finishes: gloss black, matte white, and red walnut.

Engineering, Without Compromises
What makes the Motion Series sound so amazing? MartinLogan's dedicated in-house engineering and design team started by utilizing and refining the most advanced, compact technologies and combining them with innovative engineering and time-honored cabinet construction techniques. The result is an emotionally engaging sound that rivals (and most times trounces) traditional loudspeakers of similar size and price. Our 'no compromise' philosophy gives Motion Series a unique sound you won't find anywhere else.

Folded Motion® Tweeters
MartinLogan's signature Folded Motion tweeter utilizes an extremely low mass diaphragm that "squeezes" air, thus demanding significantly less excursion than the typical 1-inch dome tweeter. Its folded design allows for a much larger surface area (compared to that of a regular 1-inch dome tweeter), controlled dispersion characteristics, and vanishingly low distortion. It's a miracle of audio engineering that's able to deliver much of the high-frequency detail and speed of a large, dynamic electrostatic panel in a small space. Folded Motion XT tweeters, advanced thin-film transducer technology even further, with a 40% larger radiating surface and 80x30-degree controlled dispersion.

Powerful Aluminum Cone Mid-Frequency and Bass Drivers
Custom built, low-distortion drivers pair high-power magnet structures with aluminum cone diaphragms to deliver massive excursion and sound output, preserve minute bass details, and maximize power handling capability, all without a hint of distortion. A unique concave dust cap design reinforces the strength and rigidity of the cone while reducing break up modes. The use of aluminum for cones maximizes rigidity and strength of the drivers without adding excessive weight. This, along with the exceptional damping properties of aluminum, ensures the smooth, non-resonant response necessary for seamless blending with high-resolution Folded Motion tweeters.

Proprietary Vojtko™ Crossover Networks
Premium Motion Series speakers feature proprietary Vojtko crossover networks using polypropylene and low-DF electrolytic capacitors, custom-wound inductors, and thermal and current protection. Vojtko crossovers are named after MartinLogan's chief audio technologist, Joe Vojtko. His unique approach to crossover design is as big of a part of the "MartinLogan Sound" as are electrostatic and Folded Motion thin-film driver technologies. A Vojtko crossover isn't so much a set of design requirements as it is a philosophy. Vojtko crossovers are designed in such a way that all drivers are kept within their optimal frequency range and balanced with one another.

Modern Design Featuring Luxurious Finishes
Discreetly hidden behind fabric wrapped magnetic grilles, Folded Motion and aluminum cone drivers are held securely in place beneath matte black trim that masks tweeter and woofer mounting hardware for a clean, modern aesthetic. Solid cabinets, designed to eliminate fidelity robbing vibrations, are constructed from 18mm (0.7-inch) MDF with 31mm (1.2-inch) thick front baffles. Motion 60XTi and 50XTi feature additional internal bracing to further reduce cabinet resonance.

Custom 5-Way Tool-less Binding Posts
Premium gold-plated 5-way tool-less binding posts assure a stable connection while accommodating bare wire, banana plug, spade lug, terminal pin, and (seldom used) alligator clip connections.

Frequency Response	60–25,000 Hz ±3dB
Recommended Amplifier Power	20—200 watts per channel
Horizontal Dispersion	80°
Vertical Dispersion	80°
Sensitivity	92 dB/2.83 volts/meter
Impedance	5 Ohms Compatible with 4, 6, or 8 Ohm rated amplifiers.
Crossover Frequency	2,700 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	5.25” (13.3cm) aluminum cone with cast 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. Polypropylene film capacitors in series and low DF electrolytic capacitors in parallel. Overall system thermal/current protection.
Inputs	Custom 5-way tool-less binding posts
Weight	12 lbs. (5.4 kg)
Dimensions	11.4" x 6.8" x 9.5 " \| (29cm x 17.3cm x 24cm)