MartinLogan Motion 15i vs. Monoprice Monolith THX-265B

MartinLogan Motion 15i Bookshelf Speaker Monoprice Monolith THX-265B Bookshelf Speakers
$900 $800
Dimensions (H × W × D)
11.40” × 6.80” × 9.50”
290mm × 173mm × 241mm
15.40” × 9.70” × 11.40”
391mm × 246mm × 290mm
Power Type
Passive Passive
Frequency Response
60-25,000 Hz 65-24,000 Hz

Key Takeaways

TLDR Summary: In the quest for audiophile nirvana within compact spaces, the MartinLogan Motion 15i and Monoprice Monolith THX-265B present intriguing choices. The Motion 15i dazzles with its Folded Motion tweeter, offering crisp, detailed highs and a warm midrange, wrapped in a luxurious design. Conversely, the THX-265B, a stoic performer, leans on THX certification for a sound that punches with precision and authority—ideal for movies and dynamic music. Ultimately, choosing between them hinges on personal taste—whether one prefers the nuanced, airy sonics of MartinLogan or the Monoprice's robust, theater-like experience. Both are sterling examples of modern audio engineering made accessible.

Speaker Comparison

The pursuit of audio perfection is a journey that leads many an audiophile down a path of endless equipment comparisons, seeking that elusive blend of clarity, depth, and resonance that can bring their favorite compositions to life. Two contenders in the realm of high-fidelity bookshelf speakers are the MartinLogan Motion 15i and the Monoprice Monolith THX-265B. Each with their own set of aural philosophies, these speakers offer distinct approaches to sound reproduction, yet they cater to the discerning ears of the audiophile community.

Design Philosophy and Build Quality

MartinLogan is a brand synonymous with elegance and precision, and the Motion 15i is no exception. The slender lines and sleek, high-gloss finish speak to an aesthetic that's as much about visual harmony as it is about sonic accuracy. In contrast, the Monoprice Monolith THX-265B presents a more utilitarian appearance, with a no-frills approach that prioritizes function over form. That said, both speakers flaunt a robust build quality, with the Motion 15i's wood-veneer panels and the Monolith's dense MDF construction providing a solid, resonance-free foundation for their acoustic endeavors.

MartinLogan Motion 15i Bookshelf Speaker
MartinLogan Motion 15i arrow (at

Sound Signature and Performance

The Motion 15i dazzles with its Folded Motion tweeter, a unique and proprietary design that delivers lightning-fast transient response and a beautifully extended, yet never piercing, high end. This tweeter's ability to articulate the subtlest of details with breathtaking clarity gives the Motion 15i an almost electrostatic-like quality, minus the bulk and complexity. On the other hand, the Monolith THX-265B, with its THX certification, is a powerhouse designed to deliver a cinematic experience. The controlled directivity and a dome tweeter ensure an expansive soundstage and a focused audio dispersion that can fill a room without becoming overbearing.

When it comes to bass, the Monolith THX-265B flexes its muscles with a larger woofer and a sealed enclosure that provides tight, impactful low frequencies. Music and movies alike gain a sense of weight and presence that can be felt as much as heard. The MartinLogan Motion 15i, while not quite as commanding in the lower register, offers a well-balanced and nuanced bass response that complements the midrange and treble without overwhelming them. The result is a cohesive and articulate sound that excels with vocal performances and acoustic instruments.

Imaging and Soundstage

Imaging is where the Motion 15i truly shines. The precision of its Folded Motion tweeter, combined with the articulate midrange driver, creates a holographic soundstage that allows each instrument and vocal to occupy its own distinct space. This uncanny ability to pinpoint the location of sound sources within a recording gives listeners the sensation of being amidst the musicians, an experience that is as immersive as it is impressive. The Monolith THX-265B, while offering a wide and deep soundstage, prioritizes an even in-room response, creating a more uniform listening experience that excels with movies and gaming, where that expansive, all-encompassing sound is paramount.

Compatibility with amplifiers is a key consideration for any speaker. The MartinLogan Motion 15i, with its efficient design and moderate impedance, plays well with a wide range of amplifiers, from modestly powered integrated amps to more robust separates. The Monoprice Monolith THX-265B is equally accommodating, though its THX certification means it shines brightest when paired with THX-certified amplifiers and receivers, ensuring that the audio chain meets stringent performance standards for a truly theater-like experience.

Value and Target Audience

Value is often in the eye of the beholder, especially in the realm of high-fidelity audio. The Motion 15i appeals to the purist who values acoustic authenticity and the kind of nuanced sound that reveals the emotional intent behind every note. Despite its higher price point, it is an investment in a pure and refined audio experience. Conversely, the Monoprice Monolith THX-265B offers an excellent price-to-performance ratio, targeting the enthusiast looking for versatility in both music and home theater settings without breaking the bank.

Ultimately, the choice between the MartinLogan Motion 15i and the Monoprice Monolith THX-265B comes down to personal preference and intended use. The Motion 15i is a masterpiece of sound artistry, perfect for the intimate listening session where every detail is savored. The Monolith, with its THX clout, is a workhorse designed to bring the thrills of the cinema into the home. Both speakers are commendable, each a testament to their manufacturers' dedication to sonic excellence.

For the music lover and the movie buff alike, the journey doesn't end with the perfect speaker—it begins there. Whether it's the MartinLogan Motion 15i's enchanting clarity or the Monoprice Monolith THX-265B's robust dynamism, the quest for the ultimate sonic experience is a personal voyage. One thing remains certain: both speakers are capable of captivating the ears and hearts of audiophiles, offering two distinct paths to audio nirvana.

Check Current Prices:

MartinLogan Motion 15i Bookshelf Speaker
MartinLogan Motion 15i Bookshelf Speaker
Monoprice Monolith THX-265B Bookshelf Speakers
Monoprice Monolith THX-265B Bookshelf Speakers

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Disclaimer: the speaker data listed on this website are correct to the best of our knowledge, but we do not guarantee the accuracy of the data. Please double-check any measurements with the manufacturer before making a final purchasing decision.