Motion 15i Speakers From Martin Logan 

28th February 2020

Including a Folded Motion tweeter, Paul Rigby reviews the Motion 15i stand-mounted speakers

A relatively small speaker, the essence of the entire design boils down to its Folded Motion tweeter technology. This thin-film transducer design crimps light-weight film into an accordion-like structure. The idea being that you can squeeze more surface area into a smaller physical space.

Spanning 2.6 x 3.6cm, the Folded Motion tweeters incorporate neodymium iron boron (NIB) rare-earth magnets, with field strengths, “…almost 20 times those of conventional magnet materials,” said the company.

Motion 15i Speakers From Martin Logan 

Under that is an aluminium coned mid/bass driver spanning 13cm. This is a custom built unit. Notice the concave dust cap design. That’s there to add strength to the cone. 

Tripping off the tongue with gay abandon is the Vojtkotm crossover that uses polypropylene and low-DF electrolytic capacitors, custom wound inductors and thermal and current protection.

Mid/bass unit with concave dust cap

During listening, I toed in the speakers so that each channel skimmed the outer ear. So, for example I positioned the left channel speaker’s tweeter pointing at or ever so slightly outside the left ear.

Strictly speaking, these are 5 Ohm speakers but they’re compatible with 4 Ohm – 8 Ohm amplifiers, so don’t be concerned about that.

Motion 15i Speakers From Martin Logan 

Spanning 290 x 173 x 238.25mm and weighing in at 5.4kg, the speakers provide custom 5-way binding posts and can handle amplifiers from 20W-200W.

Presented in Gloss Black, Matte White and Red Walnut, the rear-ported speakers also offer a wholly admirable 92db in sensitivity. 


I began with Nat ‘King’ Cole’s Thanks to You from the album, Love (Capitol). The first, rather brief, first impression was how easy (in relative terms, at least) the Motion 15i speakers were to drive. I had to lower the pre-amp’s gain by a couple of notches right from the off. 

The most long-lasting impression I had in those first few seconds was two things.

Firstly, the huge amount of space that the speakers were creating in and around the stereo image. The Cole vocal was a case in point. There was so much air infusing the Cole delivery that his performance appeared effortless and full of enthusiasm.

The air and space ventured right across the soundstage from this central point, providing plenty of room for detail to roam.

Motion 15i Speakers From Martin Logan 

On that point, the Cole vocal was brimming with detail. The midrange insight was just superb via the Motion 15i speakers. There was a sense on texture, lucidity and, above all, focus that really cut to the core of the vocal delivery here. Cole’s voice was packed with a focused texture that tracked the tiny changes across his vocal chords with no problems at all.


That focus was also notable in terms of the later trumpet solo where the precision of the instrument combined easily and effectively with the human aspect. There was no doubt that a human was playing the thing, that there were micro-faults in and around the performance that only added to the organic nature of the solo and that there was real emotion to be had, even during a cursory listen.

Bass, in terms of heft and mass, was good. Nothing more than you might expect from a speaker cabinet of this size. Again, though, the focus from the 15i speakers meant that heaps of low frequency information was forthcoming and what bass was available was delivered with impact and strength. 

Treble was a joy here, that tweeter had a large part in the creation of the air and space in and around the upper frequencies while the cymbal hits were quite ethereal in nature. 

I then turned to Thin Lizzy’s Having a Good Time from the LP, Chinatown (reissued via Back on Black).

And the result? Glorious! Truly lovely. In a word? Layers. Lots of them. This rock effort provided a delicate, detail-infused acoustic guitar with metallic filigree emerging from it. Underneath that? A chopping electric guitar (from Mr Snowy White, no less), bass was next door and under that? Percussion. Tonally spot on and realistic and the Phil Lynott lead vocal? Detached, singing in his own space, allowed to express himself without interference from other frequencies, every nuance of his delivery spotted and absorbed by the ear. The Motion 15i speakers also plugged into the emotion of the overall track so it was very easy to tap the foot and nod the head here. The production quality of this pressing is pretty good but the boxes seemed to enhance that basic quality. Never a bad thing.

I then turned to CD and Leo Kottke’s sublime acoustic guitar work on Regards From Chuck Pink (Private Music). This sort of sound source is both simple and complex, at least for a set of speakers because the plucked guitar strings are quite complex in sound terms when plucked. They produce a host of minor sonic fractures that spin off in all directions and it takes a pretty capable hi-fi system to track them all. 

The 15i speakers did just that. Kottke, a true student of the John Fahey style of craftsmanship, manipulated his guitar in a host of imaginative ways producing an orchestral suite of sounds. Each were tracked well, retaining both form and structure and without losing control and resorting to a messy smearing, skidding action in order to keep up. The inherent focus meant that detail was delivered to the ear intact, while excellent instrumental separation also means that the shy percussion lying at the rear of the mix could also be heard.  


The ability of the 15i speakers to remain naturally open, spacious and airy in the midrange without the designers having to resort to hardware tricks, such as pinching and brightening to retain a focus and enhance detail, meant that the Motion 15i  speakers sounded more expensive than they really were. The detail and clarity allowed a bucket load of information to reach the ear with no effort at all while bass precision and power was retained.  Offering a neutral presentation, the Martin Logan 15i speakers will provide an ideal fit for any musical genre and any hifi chain. Buy with confidence. 


Price: £795

Tel: 01767 686300


GOOD: low noise, balanced output, airy mids, open treble, focus

BAD: nothing


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