Martin Logan Motion 4i Bookshelf Speaker (Pair)

Sound Inspired by Electrostatic Speakers

The success of the Motion Series is directly attributed to its close relation to MartinLogan’s legendary ultra-high-end electrostatic loudspeakers. The desire to transmute that level of performance into a more traditional loudspeaker at a more affordable price drove the initial design imperatives that created the Motion Series.

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.

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. The drivers themselves are as much a part of a Vojtko crossover as are capacitors and resistors. Before the design of any crossover begins, drivers are carefully selected or designed to operate within a very intentional frequency range and with precise and predictable performance parameters. Vojtko crossovers are always built from high-quality parts, and care is taken to avoid overly complex topologies—a straightforward objective due to the careful selection of woofers and tweeters. The final (and most critical) aspect of a Vojtko Crossover is that final voicing is conducted in a space that is indicative of a real-world environment. This pragmatic approach allows MartinLogan speakers to sound their best in real-world rooms.

Modern Curves and Luxurious Finish

After refining the perfecting the acoustic details, MartinLogan designers focused on elegant yet understated styling that complements flat-panel televisions and other high-end components. To achieve this, we gave compact Motion bookshelf and center channel speakers a flawless gloss black finish and compact, slender enclosures. Subtle curves, along with MartinLogan’s signature perforated grille, add to the elegant and timeless look.