These are seriously agile speakers. They’re swift and light-footed enough to keep up with the most cluttered, rhythmically awkward tracks we could think of, and articulate enough to make sense of them. Factor in the impressive levels of clarity and fluidity, and you get an accomplished performance that feels naturally energetic.

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. This tweak increases audible bandwidth without sacrificing details and minimizes distortion to an unprecedented level while increasing efficiency and the tweeter's already lightning-fast response time. The result—superior realism and alarming specificity is aurally astounding, and only by MartinLogan.

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. An added benefit of aluminum is its outstanding thermal conduction capability which allows cones to serve as efficient heat sinks for voice coils.

To deliver accuracy in the critical midrange, mid-frequency drivers feature a specially engineered "stiff" suspension. Stiffening the suspension (the spider and surround) raises the driver's resonant frequency and optimizes its performance to achieve a natural roll-off and inherently operate within an ideal range for a mid-frequency reproduction (as opposed to a comparably sized woofer).

Martin Logan 15i Reviews and Specifications :

The Audiophile Man review

What HiFi review

 

Manufacturer's Specifications are subject to change without notice

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)