MartinLogan Motion 15i vs. MartinLogan Motion 4i

MartinLogan Motion 15i Bookshelf Speaker MartinLogan Motion 4i Bookshelf Speakers
$900 $250
Dimensions (H × W × D)
11.40” × 6.80” × 9.50”
290mm × 173mm × 241mm
12.60” × 5.60” × 5.70”
320mm × 142mm × 145mm
Power Type
Passive Passive
Frequency Response
60-25,000 Hz 70-23,000 Hz
ASR Score
n/a 1.5
ASR Score w/Subwoofer
n/a 5.1

Key Takeaways

TLDR Summary: The MartinLogan Motion 15i and 4i bookshelf speakers embody the brand's commitment to audiophile-grade sound in compact forms. The 15i, a larger speaker, boasts a more substantial bass response and greater power handling, thanks to its 5.25-inch aluminum cone woofer, while the 4i, with its 4-inch woofer, is designed for smaller spaces. Both feature MartinLogan's signature Folded Motion tweeter for crisp, articulate highs. The choice between the two often comes down to room size and listener preference for bass depth and volume, with the 15i suiting more expansive sound stages and the 4i tailored for intimate listening experiences.

Speaker Comparison

When it comes to the high-fidelity sound experiences that audiophiles relentlessly pursue, few brands resonate with such clarity and passion as MartinLogan. Among their offerings, the Motion 15i and Motion 4i bookshelf speakers stand as testaments to the brand's commitment to auditory excellence. Yet, these siblings tell starkly different stories when dissected by the discerning ear. Shall we dive deeper into the nuances that set them apart?

Design and Build: Aesthetics and Structure

The Motion 15i speaker exudes a solidity and presence that's immediately apparent to both eyes and touch. With a larger cabinet compared to the Motion 4i, it boasts a more traditional bookshelf design. This bulk is not just for show; it allows for a more expansive soundstage and bass response. Conversely, the sleek and slim profile of the Motion 4i is designed for the modern minimalist, easily blending into tighter spaces without sacrificing the brand's signature aesthetics.

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

Drivers: The Heart of the Matter

At the heart of the Motion 15i lies a 5.25-inch aluminum cone woofer paired with MartinLogan's renowned Folded Motion tweeter, which delivers precise and nuanced highs. The Motion 4i, meanwhile, features a smaller 4-inch woofer but shares the same Folded Motion tweeter technology. This common thread in tweeter design ensures that both models maintain a familial sonic signature characterized by crisp, clear trebles.

Yet, it is in the woofer size that we find a divergence in performance. The Motion 15i's larger woofer cone inherently presents a wider surface area for sound wave propagation, yielding richer and fuller bass tones. This becomes particularly evident in the way the 15i handles complex basslines and the lower registers of the audio spectrum with more authority and depth.

MartinLogan Motion 4i Bookshelf Speakers
MartinLogan Motion 4i arrow (at

Performance: Unveiling the Sound

In a listening room, the Motion 15i's prowess fills the space with a warm and embracing sound. These speakers have a certain boldness, a readiness to take on orchestral sweeps and the layered textures of live recordings with equal poise and dynamism. The sound is multidimensional, almost palpable in its spatial rendering. On the flip side, the Motion 4i, not to be underestimated, delivers an impressively balanced and articulate performance, yet it has a tendency to exhibit a lighter touch, especially in the lower end.

When it comes to stereo imaging, both the Motion 15i and 4i display MartinLogan's dedication to an immersive listening experience. The soundstage presented by the Motion 15i is notably expansive, allowing for a more precise placement of instruments and vocals within the mix. The 4i, while more compact, still manages to create a holographic aural landscape that belies its smaller stature, although it falls slightly short of the larger 15i's enveloping embrace.

Power handling is another differentiator. The Motion 15i has a robustness that welcomes amplifiers of higher power, thriving on the extra energy to flex its acoustic muscles. On the other hand, the Motion 4i is less demanding, capable of performing admirably with more modest amplification. This makes the 4i a great contender for those with limited space and power considerations, while the 15i is the choice for listeners looking to explore the limits of their sonic landscapes.

In conclusion, choosing between the MartinLogan Motion 15i and Motion 4i bookshelf speakers is an exercise in understanding one's personal listening preferences and environmental constraints. The 15i's larger frame and more robust drivers deliver a powerful and expansive sound ideal for larger rooms or those seeking a more immersive experience. The 4i, with its compact design and precise sound reproduction, offers a solution for those with space limitations or a preference for a less imposing audio setup. Both are stellar performers in their own right, staying true to the MartinLogan legacy of crafting speakers that reveal the essence of music with every note played.

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MartinLogan Motion 15i Bookshelf Speaker
MartinLogan Motion 15i Bookshelf Speaker
MartinLogan Motion 4i Bookshelf Speakers
MartinLogan Motion 4i 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.