MartinLogan Discrete Cinema Soundbar 75 – 3-Channel Passive Soundbar for 75" TVs

The MartinLogan Discrete Cinema Soundbar 75 is a premium three-channel passive LCR soundbar engineered for 75-inch-class televisions, combining true discrete left, center, and right channels in an ultra-slim aluminum enclosure. Unlike an all-in-one powered soundbar, each channel is driven independently by an AV receiver or amplifier, creating a genuine front soundstage for high-performance home theater. MartinLogan, Ltd.

Inside its 65.4-inch-wide, 2.37-inch-deep cabinet, MartinLogan uses a 13-driver architecture consisting of three Gen2 Folded Motion® Tweeters and ten 4-inch Woven Fiberglass Unibody midrange/bass drivers. With 93 dB sensitivity, 100Hz–25kHz ±3dB response, 4-ohm impedance, and 20–210 watts recommended amplifier power, the Soundbar 75 delivers substantial cinema output without the visual footprint of separate front speakers. MartinLogan, Ltd.

True Discrete Left, Center & Right Channels

The Soundbar 75 is fundamentally different from a conventional soundbar. It contains three electrically discrete speaker channels—left, center, and right—within one enclosure and requires external amplification. MartinLogan, Ltd.

That architecture preserves real channel separation. Dialogue is reproduced through a dedicated center channel while the independent left and right channels create the width, imaging, music, and effects expected from a traditional LCR speaker system.

Add a subwoofer, surrounds, and height channels, and the Soundbar 75 can become the front stage of a full 5.1, 7.1, Dolby Atmos, or DTS:X home theater while maintaining an exceptionally clean installation.

13-Driver Architecture

The Discrete Cinema Soundbar 75 uses:

3 × Gen2 Folded Motion® Tweeters
10 × 4" Woven Fiberglass Unibody midrange/bass drivers

MartinLogan specifically increases driver density as screen size increases across the Motion Discrete Cinema range. The Soundbar 75 expands both the left/right sections and center-channel woofer complement compared with the 65-inch model, providing greater acoustic capability for a larger display and room. MartinLogan, Ltd.

This is MartinLogan's Acoustic Scale concept: the speaker isn't simply made wider to visually match a larger television—the acoustic system itself is scaled with the screen.

Gen2 Folded Motion® Tweeters

Each of the three channels receives its own 1" × 1.4" Gen2 Folded Motion Tweeter (FMT) with a 5.25" × 1.75" folded diaphragm and dedicated Folded Motion Waveguide. MartinLogan, Ltd.

The folded diaphragm moves air by squeezing it through its folds rather than operating like a conventional dome tweeter. The architecture provides a large effective radiating area from a compact assembly, making it particularly well suited to the Soundbar 75's shallow enclosure.

90° × 90° Folded Motion Waveguide

MartinLogan pairs each Gen2 FMT with a Folded Motion Waveguide engineered for 90° horizontal × 90° vertical dispersion. MartinLogan, Ltd.

Controlled dispersion helps maintain consistent high-frequency coverage across the listening area while reducing unnecessary acoustic energy outside the intended listening window—particularly useful in modern living rooms with large displays and reflective surfaces.

Ten 4" Woven Fiberglass Drivers

The Soundbar 75 employs ten 4-inch Woven Fiberglass Unibody cones, each using a 1.5-inch high-temperature voice coil. MartinLogan, Ltd.

Woven fiberglass combines low mass with high rigidity, helping the compact drivers maintain controlled piston behavior during demanding movie soundtracks. The larger driver complement also gives the 75-inch model the cone area required to create a front soundstage with greater scale and dynamic capability than a typical low-profile soundbar.

100Hz–25kHz Frequency Response

MartinLogan specifies the Soundbar 75 at 100Hz–25,000Hz ±3dB. Rather than compromising the enclosure by attempting to extract deep bass from a cabinet only 2.37 inches deep, the design concentrates its available volume and driver capability on the critical midrange and high-frequency spectrum. MartinLogan, Ltd.

MartinLogan recommends completing the system with at least one high-performance subwoofer. This lets the Soundbar 75 handle dialogue, imaging, detail, and cinematic dynamics while a dedicated subwoofer reproduces the demanding low-frequency effects channel and deep bass. MartinLogan

93dB Sensitivity & Up to 210W Recommended Power

At 93dB sensitivity at 2.83V/1m, the Soundbar 75 is relatively efficient for a low-profile passive loudspeaker system.

Its nominal impedance is 4 ohms, with MartinLogan specifying compatibility with amplifiers rated for 4-, 6-, or 8-ohm loudspeakers. Recommended amplifier power is 20–210 watts. MartinLogan, Ltd.

This provides considerable flexibility when building the system around a premium AV receiver or separate multichannel amplification.

2.5-Way Crossover

The Soundbar 75 uses a 2.5-way crossover architecture, allowing MartinLogan to control how its multiple midrange/bass drivers operate across the frequency spectrum rather than simply running every driver identically. MartinLogan, Ltd.

That becomes particularly important with ten 4-inch drivers distributed across three channels, where crossover behavior, driver interaction, dispersion, and acoustic summation all influence the final soundstage.

Sealed Extruded-Aluminum Enclosure

The entire 13-driver system is housed in a rigid sealed aluminum cabinet.

MartinLogan uses extruded aluminum to achieve two objectives: its structural rigidity helps suppress cabinet flex and resonance, while its strength permits thinner walls than conventional MDF. Thinner walls preserve more internal air volume for the drivers without increasing the exterior depth. MartinLogan

The result is a cabinet measuring only 4.76 inches high and 2.37 inches deep.

Designed for 75" TVs

At 65.4 inches wide, the Discrete Cinema Soundbar 75 is proportioned specifically for 75-inch-class televisions. MartinLogan, Ltd.

Rather than placing a short conventional soundbar beneath a large screen, its width and acoustic architecture create a front soundstage more appropriately scaled to the image. Curved endcaps soften the visual transition between speaker and wall while maintaining the clean geometry of a modern flat-panel installation. MartinLogan

Wall Mount Included

A low-profile wall-mounting system is included, allowing the Soundbar 75 to sit close to the wall beneath the display. MartinLogan also incorporates cable-management provisions to help conceal speaker wiring. MartinLogan

Your September 2026 MartinLogan dealer sheet likewise identifies the Soundbar 75 as a three-channel low-profile passive soundbar with the wall mount included. Motion Discrete Cinema - USR51 …

Optional TV Mounting System

MartinLogan offers a dedicated Low Profile Speaker TV Mount Kit compatible with the Soundbar 75 as well as the Soundbar 65, Soundbar 85, LCR5, LCR7, and LCR9. Motion Discrete Cinema - USR51 …

This allows the speaker to mount with the television rather than independently to the wall—particularly valuable with articulating TV mounts because the front soundstage can remain physically aligned with the display as it moves.

Tool-Free Speaker Connections

Motion Discrete Cinema speakers use a removable tool-free speaker-wire connector. The installer can terminate the speaker wiring before hanging the soundbar, with tension levers securing the conductors without requiring a screwdriver. The completed connector then plugs into the rear of the speaker. MartinLogan

For a 65.4-inch-wide speaker mounted tightly beneath a television, that is a meaningful installation advantage and helps preserve the clean appearance the series is designed to achieve.

Technical Specifications

These are MartinLogan's current published specifications. MartinLogan, Ltd.

Shipping Specifications

Your September 25, 2026 MartinLogan sheet separately lists 69.1" × 8.9" × 6.1" shipping dimensions and 21 lb shipping weight. Motion Discrete Cinema - USR51 …

I would keep those strictly as Shopify shipping data rather than mixing them into the customer-facing product dimensions.

MartinLogan Discrete Cinema Soundbar 75 at The Grid HiFi

The Discrete Cinema Soundbar 75 is designed for systems where the visual simplicity of a soundbar is desirable but the performance limitations of a conventional powered soundbar are not. Its three discrete channels, 13-driver architecture, Gen2 Folded Motion tweeters, external amplification, and 2.37-inch depth make it a compelling front-stage solution for premium 75-inch TV installations.

The Grid HiFi can build the complete system around it with the appropriate AV receiver or processor, amplification, subwoofer, surrounds, Dolby Atmos channels, television, mounting, concealed wiring, Control4 automation, networking, and professional calibration.

For an especially streamlined installation, MartinLogan's USR51 ultra-slim 5.1 receiver provides 50 watts per channel, Anthem Room Correction (ARC), HDMI eARC, wireless streaming, and control integration. Motion Discrete Cinema - USR51 …

Building a high-performance theater around a 75-inch TV? Call The Grid HiFi at (713) 218-8120 for expert system design, matching, and installation.