Sonner Audio Legato Unum Loudspeaker | REVIEW

sonner audio legato unum

The story begins with my coverage of the Sonner Audio (website) Legato Unum at hi-fi shows, and what I found accompanying the brand. Touring the hi-fi show circus circuit I often found myself face-to-face with many of the audio industry’s most interesting characters. The bulk of them are pleasant and interesting people. A select few are extraordinarily engaging and charming. Gunny Surya, the President of Sonner Audio, easily fits into all of those aforementioned descriptions. If you care to explore our past show coverage of Sonner Audio loudspeakers, those articles can be found here, here, here, and here.

Words and Photos by Eric Franklin Shook

I feel very comfortable around people like Gunny Surya. His personality is not an act. The idea of him having a facade seems totally unfathomable. There is no artifice with him. Whether it’s the genuine passion he expresses for his company, or the earnest way he treats others with the same respect often reserved for long-time friends and family. It’s these little actions and details that collectively tell the same story: Gunny is true to himself and to those around him. He cares about what’s really important in life and so he guides Sonner Audio with that same truth and honesty.

Sonner Audio is celebrating their fifth year anniversary in 2020 , and doing so with many industry awards and accolades under their belt. The company may be only five years old, but the industrial design and electrical engineering team have been building loudspeakers for over twenty-five years. What the future holds for Sonner Audio is yet to be written, but my money is on brand growth and domination. Sonner Audio makes exciting products that surely will continue to gather awards and devoted customers along the way.

sonner audio legato unum

The Sonner Audio Legato Unum

The Sonner Audio Legato Unum is a stand-mount loudspeaker that stands apart in a crowded field of able bodied competitors in the $5K range at just $4,750 USD. As anyone who’s ever built and sold loudspeakers in that competitive price category knows, creating a standout product in that market can be harder than putting grill marks on a microwaved steak. But, somehow I think Gunny and Sonner Audio have done exactly that.

The Legato Unum is an American made two-way ported loudspeaker, and the smallest of Sonner Audio’s entry level Legato series. It features a 1-inch ring radiator tweeter, a 5.5-inch coated paper cone woofer, and a point-to-point wired fourth-order Linkwitz-Riley crossover. At the heart of it all, the Legato Unum is a just scaled-back version of the Sonner Audio’s higher-end Allegro Unum which itself retails for $12K (including stands). The more affordable Legato Unum benefits from Allegro’s time aligned cabinet, crossover design topology, and monocoque curved rear panel.

All of Sonner Audio’s speaker models are designed around a Low Energy Storage concept and Driver Time Alignment design. The inherent strength of the curved speaker cabinet used for the Legato Unum (shared with Allegro) is how it provides a rigid structure that reduces internal standing waves and releases sound energy quickly without adding or subtracting from the original amplified signal.

The front baffle of the Legato Unum is built at an angle to incorporate a time alignment design. The angle is calculated during computer modeling and validated with many listening tests. This approach results in a stable and precise imaging soundstage that plays larger than expected. The black front face-plate functions as the tweeter’s acoustic lens, and indeed sounds better when installed. The speaker also comes with an acoustically transparent grill that can be magnetically mounted on top of the leather faceplate.

sonner audio legato unum

Loudspeaker Setup

I don’t need to tell you that the Sonner Audio Legato Unum loudspeakers prefer to be pulled off the back wall. Most speakers need that to exhibit with better depth and imaging in the sound-stage. It’s true here with the Legato Unum. I also don’t need to tell you that loudspeaker toe-in had an effect of tightening up the center image. With most speakers that is a known attribute. It’s not needed with the Legato Unum in my experience, but your mileage may vary. What I do need to tell you about is the stands.

The Sonner Audio Legato Unum is a stand-mount loudspeaker. Which means you need stands, at which point Sonner Audio offers a veneer matched set that retails for $1,120 USD. That sounds like quite the outlay for a pair of speaker stands, but I implore you to take them seriously as my experience using them yielded substantial improvements to the Legato Unum’s performance.

When the speakers first arrived, they arrived without stands. During the shipping process there were a few delays. The first two boxes to arrive were the Sonner Audio Legato Unum speakers. It would be another six days of waiting before the Sonner Audio stands were delivered. Wait for them, I did not. The stand-mount monitors were placed on a pair of 24-inch solid metal stands that I had borrowed from fellow Part-Time Audiophile contributor Nan Pincus. There they stayed while I listened for the following six days.

Once the Sonner-designed 27″ stands arrived I switched over for a comparison. Immediately it became clear why the listening height of these loudspeakers was so important. When I had the Sonner Audio designed stands in the system, everything came together in the sound. The mass coupling of these heavy wooden stands offered much more in stabilizing the image plane and ensuring the cleanest bass possible when compared to the 24” metal stand.

sonner audio legato unum
Christopher Livengood positioning the Sonner Audio Legato Unum

On The Road

It’s not uncommon for me to take a review sample out on the road to gather extra performance data using different rooms and systems for comparisons. First in this journey, it was fellow Part-Time Audiophile contributor Dave McNair’s home system where I was able to establish a new appreciation for what the Sonner Audio Legato Unum speakers could do against upstream componentry. Second was my visit to Christopher Livengood’s hi-fi store Ember Audio + Design where Chris and myself discovered how well the Legato Unum performed in a well treated large exhibit space.

Dave McNair’s home is an exciting place to listen to music. Dave’s system is in a state of constant change with new review samples coming and going almost monthly. Once I arrived, Dave had the Dynaudio Special Forty monitors set up for us to establish a baseline sound for monitor sized sound. Listening to a few tracks it was easy to see why Dave purchased the Special Forty for his personal system. Great bass, and smooth top end.

When switching over to the Sonner Audio Legato Unum, the differences were quite strong. The top-end of the Legato Unum to my ears were much more open and detailed. Mid-bass was crispier, while giving away ultimate depth in response to the Special Forty. Character wise, the Special Forty was a warmer sound, while the more detailed Legato Unum exhibited more neutrality.

From there we switched in the highly regarded and loved Qln Prestige Three towers which should, in their retail cost and generous cabinetry, be an outright shoe-in to best the Sonner Audio Legato Unum loudspeakers. But the Legato Unums held their own, only giving way to the larger Prestige Three in the larger cabinet’s obvious bass extension and having a slightly less smooth presentation of the treble when compared to the Prestige Three’s tweeter. It’s here where I am delighted to find the Legato Unum punching well above its weight class.

sonner audio legato unum
Christopher Livengood listening to the Sonner Audio Legato Unum

My next adventure took me to Ember Audio + Design, where Christopher Livengood and I installed the Sonner Audio Legato Unum into the listening room’s main system and resigned ourselves to a comfortable hour of plunging through various records and streaming tracks. The Legato Unum monitors never once seemed outpaced by the dimensions of the room, doing well to produce a clean sense of scale and imaging, with unexpected success in bass quantity and control when attached to the Naim Supernait 3. The way the Naim had a grip on this relatively small monitor was duly impressive.

The Sound of the Sonner Audio Legato Unum

The Sonner Audio Legato Unum speakers deliver a level of detail that is hard to find elsewhere, producing a realistic and focused musical soundstage with ghost-like imaging. They can, however, verge on being a bit energetic in the top of the frequency range, but the resulting communicative factor is so appealing and smooth that other monitors by comparison sounds either weak-willed or too shouty. Mid-bass textures on the Legato Unum are to die for. Cello strings specifically have a grit to their sound that is hyper-realistic and magnified. Imagine the feeling of sixty-grit sandpaper between your fingers, now place the sandpaper to your lips. It can almost become too much sensory information, but more likely you’ll find it as addictive as I did.

In my listening spaces, the Sonner Audio Legato Unum had a way of presenting bass in this taught and deep-reaching manner that comes unexpectedly. Bass is powerful, dynamic, and clean for a monitor of this size or even larger. Though we’re just talking about the bass quantity here, it’s really more about the musical information provided throughout the frequency bandwidth that allows the bass note quality in the Legato Unum to fully render the instruments. The mid-bass drivers of the Legato Unum produce something that feels lifelike as percussion instruments are presented with the due crack and snap of a freshly picked green bean.

My single caveat with the Sonner Audio Legato Unum is this: when paired with exceptionally bright electronics the upper-frequency response can become a bit out of balance and thus go over the edge. When paired with amplification from the neutral territory of class-A/B, on down to those syrupy warm and gooey class-A tube electronics, it’s all smooth sailing. Pairing the Legato Unum’s with Naim amplification specifically, the balance was revelatory. Paired with the more refined class-D offerings was also quite thrilling and nothing to be avoided.

sonner audio legato unum

“You took the ‘shrooms, and yet it’s I who feel the high.”

These beautiful speakers ride the upper edges of detail so adeptly, that it demands a strange comparison. If the Sonner Audio Legato Unum speakers were a hallucinogenic drug experience, they would be a micro-dose of Psilocybin mushrooms. Like a small dose of the magic mushroom, the Legato Unum forces you to observe things differently.

Colors are now more vibrant and the musical texture is abundantly more exposed. For what may feel like the first time, you can now see and hear the music. Soon after, you begin to think that maybe you never were truly alive until now, and this thought leaves you feeling a bit melancholy. You are in touch with all of your emotions, because now every musical performance has its meaning, beauty, and richness magnified.

With the Sonner Audio Legato Unum familiar songs jump out at you with new information, causing you to either fall in love with them again, or to confront your past experiences. You eventually come to grips with the knowledge that the music you hold so dearly was in fact hiding something all this time—its soul in detail. You now feel satisfied with equal measures of love and heartbreak. Can you really have one without the other?

sonner audio legato unum


My main system’s floor-standing loudspeakers feature four dynamic drivers each, the largest of which being a 10-inch woofer that extends bass down into the high 20 Hz region. With that, I’ve often wondered if I could ever find the same level of enjoyment from my system if I were forced to scale down to a two-way stand-mount monitor.

With the arrival of the Sonner Audio Legato Unum, I’ve reached peak metanoia. Not only could I find myself wholly satisfied with the two-way stand-mount as the main loudspeaker in my reference system, I could further say that it would be an improvement.

Several loudspeakers have the gift of detail. What’s special with the Sonner Audio Legato Unum is the clean and sophisticated way in which they present each region of the music with coherence, complete detail and composure.

The Sonner Audio Legato Unum’s will grab your mind, your attention, your heart; something several speakers on the market—even the most detailed ones—often can’t and won’t do. The Legato Unum speakers excel at breathing honesty and life back into the music.

Often my well of metaphors runs dry, and the stash of ten dollar words I approached this avocation with were spent quickly in my first year of reporting. To now fall back on the old-and-tired reviewer’s figure-of-speech—”highly recommended“—just feels icky. So without shame, I’ll leave you with that which a great audio writer I know once said, and said pretty good, “They are not on your shortlist, they are your shortlist.”

David, your check is in the mail.

The Sonner Audio Legato Umum takes home our coveted Editors’ Choice award, and still come highly recommended.

Sonner Audio Legato Unum

Retail: $4,750 pair USD

Stands: 27-inch pair $1,120 USD

Tweeter: 1” Ring Radiator

Woofer: 5.5” Coated Paper Cone

Design: 2-way Ported, Crossover Frequency at 2.5 kHz,

Sensitivity: 87.5 dB

Nominal Impedance: 8 Ohm

Minimum Impedance: 5 Ohm

Frequency Range: 43 – 23k Hz.

Speaker Dimension without stand: 8.27” Width x 12.6” Height x 17.75” Depth

Speaker Dimension with stand: 8.27” Width x 40” Height x 17.75” Depth

Sonner Audio:

sonner audio legato unum

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