Focal Sopra N°1 Bookshelf & Center Speaker Review: Looks that Kill!

Focal Sopra N°1 Bookshelf Speaker Introduction

On the many occasions that I have heard Focal speakers, I have always been left impressed by the sound, but I never thought I would get some in for review to spend serious time with them. Perhaps the reason is that Focal is a European brand, and I have just spent a lot more time with American, British, and Japanese brands than European manufacturers. Hopefully, that can now change, and this review will start a trend for dealing with European brands. Not only do I now have an opportunity to dig into some Focal speakers, but I have been sent some advanced high-end designs for review as well in the Sopra series.

Focal Sopra No1 Bookshelf Speaker YouTube Review

Today’s review will be covering the Sopra N°1 bookshelf speaker and Sopra Center speaker, Focal’s highest-end line next to the Utopia series. Both of these speakers cram cutting-edge loudspeaker engineering into an extremely attractive package. Needless to say, high-end performance combined with high-end looks often commands a high-end price tag, and, at nearly $10k for the bookshelf speaker pair and $4k for the center speaker, these do, but that doesn’t mean they aren’t a good value. If you want attention to detail in every facet of your sound system, with no compromises outside of the form factor itself, that takes some extreme engineering and manufacturing processes, and it isn’t inexpensive to do all of that. Such a product is priced high for a good reason, and the question that we have to ask when we have high-cost products in for review is that pricing justified by the caliber of the product? Let’s now take a close look at the Sopra speakers to get an answer…

Appearance

The Sopra No 1 arrived in a very tough cardboard box with thick polyurethane foam blocks providing a good cushion from shock and space from the box sides. Inside that, they were wrapped in a luxurious rayon drawstring sack to protect against moisture and scuffing. Once out of the sack, the speakers were revealed to be a stunningly beautiful design. The Sopra bookshelf speakers had a rounded enclosure with an angle at the portion continuing the tweeter. The tweeter’s housing was made from black brushed aluminum, and in the back, there was an aluminum wireframe protecting an opening (whose function we will describe in the ‘Design Analysis’ section). The main bulk of the cabinet was finished in a very fine gloss black with a slight scintillation that you might find in a luxury car finish. The Sopra bookshelf speakers were topped off with a glass piece with gently beveled edges.

The tweeter was protected by a built-in aluminum wireframe grille, but the woofers have a removable grille that is just a fabric-covered round plastic frame. However, the woofers look so gorgeous (as woofers go) that I wouldn’t dare hide them with a grille. The woofers are sunk fairly deep into the cabinet, and the cones have a marble look to them. They are encircled by a nice brushed aluminum trim ring. The Sopra center is mostly the same except it doesn’t have a separate chunk of the cabinet for the tweeter, nor does it have the Sopra bookshelf speaker’s tweeter ‘vent.’ It is a three-way design using the same kind of marble looking midrange cone as the bass drivers. The Sopra center has the midrange driver and tweeter set into a black brushed aluminum panel on the front baffle.

All in all, the Sopra speaker set has a truly high-end demeanor, both in looks and in feel. These are heavy for their size; the Sopra bookshelf speakers weigh nearly 42 lbs each. The build quality is clearly at a very high level. These speakers are drop-dead gorgeous and among the nicest I have dealt with yet. They are not cheap speakers, but, at least in feel and appearance, you really are getting your money’s worth. These speakers are manufactured in France, and there is pride in craftsmanship in every corner.

Design Analysis

Focal has packed a lot of technology into the Sopra speakers, and so we have a lot to unpack in our design analysis. The Sopra No 1 bookshelf is a two-way design using a 1” dome tweeter and 6.5” woofer, a very common design on the face of it, but the details -and there are many details- are what separates it from other bookshelf speakers of the same basic spec set. The Sopra Center is a three-way using a 1” dome tweeter, 3” midrange, and two 6.5” woofers. That is not an unusual spec set for a center speaker, but again, it is how Focal goes about achieving these specs that elevate the Sopra Center. These speakers take traditional loudspeaker designs and boost them to the nth degree.

Let’s start our discussion of the design of the Sopra speakers at the top with the tweeter. The Sopras use an inverted beryllium dome tweeter. Beryllium is a great material for a tweeter diaphragm for the reason that it is a very light metal (30% lighter than Aluminum) and extremely stiff (4 times stiffer than Aluminum) with good damping characteristics. Other metals such as aluminum and titanium being heavier and less stiff bend and flex in rapid motions more easily than beryllium. This means that cones made out of aluminum and titanium lose their uniform motion at lower frequency oscillations than beryllium. Or, to put it another way, aluminum and titanium cones will start to bend and flex at frequencies that beryllium is able to maintain its shape. In layman’s terms, beryllium is more “pistonic” over a wider frequency bandwidth than those other metals.

Beryllium’s ability to hold its shape for a greater frequency band is a big advantage for driver performance. When cones start to flex, this is called breakup, and it can have serious negative consequences for sound reproduction. What is normally seen when cones, domes, and other transducer diaphragms begin to break up is a very erratic frequency response: large spikes of upper-frequency resonance that can sound pretty bad. For soft materials like fabric domes, the breakup resonances can be mild, but as a result of that material’s softness, they usually do not play high frequencies nearly as well as stiffer metal domes. What can be had with beryllium is a driver that can play to relatively high frequencies without the intrusion of breakup.  

The reason beryllium is seldom used in loudspeakers despite being a superior diaphragm material is the expense of manufacturing it. In its unprocessed form, it is very toxic, so it takes special procedures to safely handle versus traditional diaphragm metals. Owners of speakers using beryllium do NOT have to be alarmed about its toxicity since once it is formed into a solid shape, it is no longer hazardous (unless you try to eat it). However, the safe manufacturing procedures make it far more expensive than other tweeter types. 

Focal uses an inverted dome rather than a typical convex dome because they claim it achieves a “better mechanical interface between the voice coil and dome, ensuring that all of the vibrational energy is transmitted into the dome and radiated as sound rather than partially lost as heat in the dome surround,” to quote Focal’s white paper. In other words, they claim it is more efficient. I don’t know that it really is more efficient, but I don’t think that Focal would just decide to do that without some reason to believe it is the better choice, so I think their claim is plausible. 

The Sopra No 1 bookshelf speakers house the tweeters in an unusual compartment which has the objective of eliminating backwave acoustic radiation from interfering with the movement of the tweeter dome. I have seen other manufacturers deal with the backwave radiation from a tweeter in a number of different ways, but Focal seems to have gone the furthest in addressing this problem. The acoustic output of the rear side of the tweeter is thrown into a specially shaped compartment that absorbs it. The backwave acoustic output is reduced so that it does not reflect back, hitting the tweeter dome, thereby causing unwanted motion -and thus sound - from the tweeter. Many manufacturers will just put some soft damping materials behind the tweeter diaphragm, but the efficacy of that is normally quite frequency-dependent. Focal has gone to extremes to rid the tweeter of acoustic interference from backwave radiation, but that is the kind of attention to detail one would expect at this price point. Details can be read in Focal’s Sopra white paper linked to above.  

Moving down to the woofers, the Sopras use Focal’s vaunted ‘W Sandwich’ cone composition. This cone material sandwiches structural foam with fiberglass tissue surfaces. It is an evolution of sandwich cones that Focal has been making since the 1980s. Focal claims it is very light and rigid but also has good damping characteristics compared to cones using a single material. Focal is not the only manufacturer making these types of layered cones in an effort to make something that is light, rigid, yet well-damped, but their solution of using structural foam does seem to be an inspired choice. 

Moving out from the cone to the surround, Focal uses the principles of a tuned mass dampener in the design of the surround. A tuned mass dampener is where a weight is attached to a heavier object with a spring, and the weight combined with the spring is tuned to counterbalance the resonant frequency of the attached object. Many structures use this mechanical principle to inhibit resonant frequencies from causing instability. Focal uses this principle in the surround design by adding circular beads of mass that line the surround which is specifically placed to neutralize the resonant frequencies of the surrounds. Resonances in the surround can affect the motion of the cone resulting in distortion. In their Sopra white paper, Focal has graphs illustrating the efficacy of their implementation of tuned mass damping by reducing distortion and extending the upper-frequency. They tested over 100 different prototypes to optimize the tuned mass damping in their surround design.

Focal has also gone to great lengths to reduce induction in the motor and is quite proud of the optimization done in the implementation of shorting rings toward that end. In loudspeaker motors, induction is an unintended current caused by the motion of the voice coil within the magnetic field. It can degrade the frequency response and cause nonlinear distortion. Shorting rings (also known as ‘Faraday Rings’) have an induced current that creates a magnetic field that helps to neutralize the effects of induction in the voice coil. Focal ran through many simulations of common implementations of shorting rings through sophisticated computer modeling and found the one that works best. In their white paper, they show a multitude of graphs that demonstrates the lower inductance of their designs as well as the improvements in frequency response linearity that it yields.

The cabinets for the Sopra speakers use what Focal calls the “Gamma Structure.” Diving into the literature, this is just a fancy term for practices that many other high-end loudspeaker manufacturers are doing as well. It indicates a combination of extensive internal bracing, thick front baffle, and curved side panels. Focal says that the front baffle on the Sopra speakers is 69mm thick (approx 2.7” thick). That is extremely thick, obviously, but given how deeply the woofer is set in the front baffle, it is plausible. Focal uses MDF for all wood components. While it might seem pedestrian to use MDF in a speaker at this price point instead of a more exotic material, one aspect of MDF that makes it such a great loudspeaker enclosure material is that it is tough while having good damping properties. A material that is too stiff can be more susceptible to resonances. Furthermore, MDF is thicker on the sides than the center, and this difference in density can also mitigate resonances. The heavy finish of the Sopras will no doubt contribute to this effect since it likely required many layers of lacquer to attain. The extensive use of MDF, as well as the aluminum and glass pieces, are pretty good assurance that the Sopra enclosures will be inert. The Sopra bookshelf speakers weigh nearly 42 lbs. each, even though they are not especially large, and that is evidence of the extraordinary level of build quality in them.

Both the Sopra No1 and Sopra Center are ported loudspeakers with slot ports on the back of each speaker. The port is built into the cabinet, at least as far as the panel extends, and there is a slight flaring on the outer edges. Both speakers include foam port plugs for those who want to seal the ports. Sealing the ports could help the speakers integrate with subwoofers better since ports can cause some odd phase behavior that isn’t as easy to match at the sub crossover point. Sealing the center speaker may also be a good idea if the center has to be placed in a more enclosed space where boundary gain can really bump up the bass levels. Elevated mid-bass can hurt speech intelligibility so it’s something to avoid in a center channel speaker. Outside of these circumstances though, I don’t see a good reason to seal the ports.

The Sopra No 1 Bookshelf speakers have their crossover frequency at 2.2 kHz, and the Sopra Center speaker has its crossovers at 500Hz and 2.2kHz. One nice thing about the Sopras is that Focal doesn’t give you the option of bi-amping or bi-wiring, so there is only one set of binding posts. The reason why that is good is that it would be absurd to bi-amp or bi-wire these speakers. A case can be made for bi-amping large speakers with a formidable bass section, but there are no practical gains to be made to bi-amp speakers in this product class. Focal could very easily have pandered to misguided audiophiles and included that, but they choose to be sensible about the inclusion of that feature. Most users are more likely to do more harm than good when bi-amping or bi-wiring speakers like these.

The Sopras have very heavy-duty binding posts. They are large five-way binding posts and have some big knobs to tighten the caps. I did encounter some small problems with these posts. The banana plug tips on my speaker wire were too small to fit in the banana plug holes for two different types of banana plugs that I had on hand. Furthermore, the cap knobs were so large that they couldn’t tighten the banana plugs when I inserted them into the cross hole because the banana plug base got in the way of the knob rotation. I would say users should just make it easy on themselves and use a bare wire connection. The Sopra speakers do not come with feet, but they do come with some small adhesive soft dimples that the user can choose to attach to the bottom if they don’t want the speakers to rest on a surface directly. There are three screw holes on the bottom of the Sopra bookshelf speakers, but they are intended for mounting on Focal’s stand that can be additionally purchased. 

Altogether, the Sopra No 1 bookshelf speakers and Sopra Center speaker have a level of build quality and immaculate attention to detail in every facet of design that is befitting their cost. Loudspeaker design is interesting and all, but it only serves the purpose of sound, so now it is time to give them a listen to hear what all this sophisticated design adds up to…

Listening Sessions

In my 24’ by 13’ (approximately) listening room, I set up the speakers with stand-off distances between the back wall and sidewall, and equal distance between speakers and listening position. I angled the speakers to face directly at the listening position. Listening distance from the speakers was about nine feet. Amplification and processing were handled by a Pioneer Elite SC-55. No room correction equalization was used. Subwoofers were not used unless otherwise noted.

Music Listening

Starting with an album that emphasizes vocals, I found a pristinely recorded folk music production in an album entitled ‘Bonny Light Horseman’ from a new group of the same name. Bonny Light Horsemen is comprised of three veteran musicians from rock, indie, and folk music who came together to perform some very old and simpler compositions. Much of the music performed on this album was written centuries ago, and Bonny Light Horseman keeps the simplicity intact but does update some of the lyrics to be more resonant in this modern era, but without losing the spirit of the original music. This production keeps the music on an intimate level with only a slight reverb suggesting a larger space. The vocals and instruments are beautifully recorded, and the separate performers are integrated wonderfully without getting lost in the mix in this masterful production.

The Sopra No 1 bookshelf speakers proved to be a fantastic match for ‘Bonny Light Horseman.’ The instruments and vocals especially were exquisitely detailed but without the excess treble that lesser loudspeakers use to create a sense of detail. On the Sopra speakers, the vocals of the leads were so well-defined that it was as if the performers were singing in my living room. They had a lifelike presence. The natural tonality was certainly aided by their sublime imaging. Through the speakers, it was easy to sense that the performances were all microphoned at a close distance and that the soundstage that was created was largely a matter of mixing choices. This didn’t lead to a natural soundstage across the width of the speakers but rather a centered performance that cohered in a space between the speakers. The effect accentuates the harmony of the players more than concrete positioning for each player. I would guess that suited this music more than trying to render a realistic stage. Nonetheless, the recording sounded fabulous, and I am eager to use it on future speaker reviews to see how well it would compare to the Sopras, which surely sets a high reference point.

For music on a grander scale, I found a marvelous recording of Igor Stravinsky’s ‘Persephone’, an opera written for ballet in 1934 about Zeus’s daughter of the album’s name. It is now considered one of Stravinsky’s greatest works, although it wasn’t that well-received at the time of its release. This is a varied work with many different musical elements that were considered uneven. However, it makes for a good demonstration of a sound system’s ability due to the sheer diversity of styles within the work. It has choral segments, vocal and instrumental solos, as well as complex orchestral passages. The recording I listened to was released on the PentaTone label in 2018 and was performed by the Finish National Opera led by Esa-Pekka Salonen and joined by lead tenor Andrew Staples and actress Pauline Cheviller. The recording has superb sound quality especially considering it is a live recording of the performance at a classical music festival. I streamed this from Qobuz at a 24-bit/96kHz rate.

On the Sopra speakers, it sounded as if I had the best seat in the house. It was as if I were sitting in a forward position but not so close where the choral and orchestral elements lose cohesion. Solo moments had clearly defined positions, and it was easy to distinguish the sections of the orchestra, yet the overall recording put the listener very much in the center of the concert hall. Orchestral and choral parts had a lush yet vivid sound, and the soloists were terrifically detailed even though it was evident that the performance was not recorded with close mic’ing. The Sopra speakers were able to give life to the louder moments while not losing any detail on the quieter moments. The bass ability was surprising for a mere bookshelf speaker, and I didn’t feel as if I had missed anything by not using a subwoofer. Perhaps I shouldn’t be so surprised that the Sopra’s were so capable given the level of technology, build quality, and cost. However, I was nonetheless impressed by the big sound that I received from such modestly sized speakers. I am sure that classical music fans would be very happy with a pair of Sopra bookshelf speakers, especially those who don’t have room for tower speakers or subwoofers.   

Going back to something more tightly focused on a singular human voice, Ghalia Benali’s ‘Romeo and Leila’ is a simple and uncluttered recording of a female vocalist backed by a handful of instruments. This 2006 release puts Ghalia’s voice front and center with one or two layers of instruments supporting her. This recording, sung in Arabic, tells an autobiographical story of Ghalia in terms of established myths such as Rubaiyat of Omar Khayyam. However, since I don’t understand Arabic, it could be a recipe for an egg-salad sandwich for all I know, but if it is, it is the most beautifully narrated recipe that I have heard. Ghalia’s range and dexterity are magnificently displayed on this recording, much more so than other recordings that she is featured on since there is not a big instrumental section to mask her voice. This allows for a more detailed exhibition of Ghalia’s talent and also makes ‘Romeo and Leila’ a good album to demo for a sound system. 

On the Sopra speakers, Ghalia’s singing was presented with an uncanny realism whether she was whispering, shouting, celebrating, or lamenting. Her delicate voice was anchored at dead center in the soundstage with no ambiguity. Similarly, the instruments accompanied her with well-defined placement. Nothing sounded unnatural or colored in any discernible way. I could only imagine that this is what this recording is intended to sound like. The Sopra speakers add or subtract nothing and only recreate what was present in the signal. If you want to hear the musical performance as though you are in the same room as the performers, these speakers are a great choice. ‘Romeo and Leila’ was a mesmerizing listening experience on the Sopra speakers, and that is a common occurrence when you combine tremendous musical talent with expert sound recording and a high-fidelity sound system.

Taking a radically different turn, I decided to listen to something bombastic that would push these speakers quite a bit harder. Towards this end, one nifty soundtrack that I found on Qobuz was Carpenter Brut’s score for the 2019 science fiction movie ‘Blood Machines.’ “Blood Machines’ is a very strange but colorful and energetic film that is perfectly accompanied by a similarly colorful and energetic music score. The music is all electronic and has a retro vibe, clearly taking influence from 80’s synth scores from the likes of John Carpenter’s scores for his own movies (doubtlessly the homage in the ‘Carpenter Brut’ stage name) or Goblin’s scores for Dario Argento’s horror films. This score is an epic, pulsating, kaleidoscopic tour de force; it is bass-heavy, atmospheric, and has a relentless and memorable arpeggiated sequence at its core that demands to be played loud.

I cranked the volume up to see what the Sopra No. 1 bookshelf speakers could handle. The first thing that I noticed is just how capable these speakers are in bass frequencies. The ‘Blood Machines’ score has a lot of bass, and these bookshelf speakers with their seemingly modest 6.5” woofers were handling it all just fine. It could be that I was pushing these speakers right up to their limits and was just a hair away from over-driving them, but I was listening as loud as I was comfortable with and the Sopra speakers didn’t seem to mind at all. The inclusion of a subwoofer might have given the lowest octave a bit more punch, but the Sopras didn’t sound like they needed any help. This bass was satisfyingly loud and punchy. Along with their superlative bass performance, I never heard a hint of compression, distortion, or anything to suggest that the speakers were outside of their comfort zone. The ‘Blood Machines’ score has a lot going on but the sound was never muddy or confused; in fact, this was as good a presentation as I have ever heard (memo to self: listen to this album at least once more on the Sopras before returning them). On the ‘Blood Machines’ score, the Sopras proved that though they look elegant and refined, they could rock hard when commanded. Maybe it is more than just serendipity that Carpenter Brut’s music sounded so good on the Sopras since he is a French artist being replayed on French-made speakers, but I think the case is rather that these speakers will make any good recording sound terrific.

Movie Watching

One movie I finally had a chance to see was Christopher Nolan’s recent science fiction opus ‘Tenet.’ Tenet is a complicated movie about time travel, and I won’t say more than that so as not to spoil the plot developments for those who haven’t seen it. As with other major Hollywood tentpole movies, ‘Tenet’ is filled with large action set pieces and a massive orchestral score, so, with the Blu-ray disc in hand, I figured it would be a good chance to show off the Sopra’s chops with something that had a very wide dynamic range. I also decided to use certain segments with the subwoofer active versus the speakers running full range, to see how much a sub could bring to material that was sure to have plentiful deep bass. Along with other Christopher Nolan productions, ‘Tenet’ has been criticized for having unintelligible dialogue due to the loudness of the music and effects noises. Would the Sopra speakers be able to save speech intelligibility in a Christopher Nolan movie? I decided to find out.

After watching the movie, I was quite impressed with the Sopras’ performance, although they weren’t able to completely make all the dialogue decipherable. For example, in scenes where the characters were talking through respirator masks, it could be difficult to understand what they were saying at times, but I don’t think that any sound system could have made that intelligible. On the other hand, in action scenes where music and effects sounds can drown out the dialogue, I didn’t have a problem following what the characters were saying. I watched the movie at a loud level, and I never felt as though the speakers were strained, so they seemed to handle the dynamics very well. Gunshots, explosions, and car crashes all had liveliness, and the music score had that big-screen feel one would hope for in such an epic movie. As for bass, the speakers did very well on their own, but they don’t fully capture the lowest reaches nor do they have the visceral punch that subwoofers can provide. With a -6dB point of 41Hz, that was as expected. However, these bookshelf speakers were able to sound a lot larger than they were. In an upscale living room that doesn’t have room for a subwoofer, it would still be very easy to enjoy big Hollywood movies, even if earthquake scenes might not be as lifelike were a subwoofer in use. It’s worth noting that since these speakers are quite adept at bass on their own, a higher-performing subwoofer with serious extension down to 20Hz should be used to accompany them, or else the sub might not add enough to be worth it.  

A Blu-ray disc set that I had had for some time but hadn’t got around to watching was ‘Twin Peaks: The Return.’ One of my all-time favorite television shows is the original ‘Twin Peaks,’ so I was very excited about the return of ‘Twin Peaks,’ but the ‘Return’ series is 18 episodes and each an hour-long, which is quite a time commitment these days. Nonetheless, I carved out some space in my schedule, turned off my phone, and spent 1,030 minutes watching ‘Twin Peaks: The Return’ since I had the Sopras in house and used this review as an excuse to finally watch this series under the rationalization that I was “working on a project.” However, it would be a good test of the Sopra Center’s ability to reproduce speech since ‘The Return’ would doubtlessly be heavy in dialogue, and it would also be great to hear Angelo Badalamenti’s always wonderful score through the Sopra bookshelf speakers. And so, back I went to David Lynch’s fascinating logging-based township.

‘Twin Peaks: The Return’ turned out to be a more sonically immersive experience than I expected, and I was glad to have had such capable speakers to enjoy it with. It really does benefit from a high-fidelity sound system, more so than most shows. Each episode ends with a live musical performance in the ‘Bang Bang Bar’ by a diverse line-up of distinguished musicians such as Rebecca Del Rio, Nine Inch Nails, Eddie Vedder, Julie Cruise (whom Twin Peaks fans will remember for doing the vocals from the original Twin Peaks music), and Moby, among others. Every performance was a delight to hear on the Sopras. Furthermore, the sound design for the entire series was done by David Lynch himself, and sound plays a big role in establishing the peculiar atmosphere of ‘Twin Peaks: The Return.’ Large sections of the sound mix are just complex effects sounds mixed with music since much of it occurs in an abstract realm of dream logic. It all sounded fantastic on the Sopra speakers. Speech intelligibility was never a problem as well (except in the ‘Black Lodge’ where dialogue was recorded backward but replayed in reverse for an eerie effect). Badalamenti’s music sounded as great as ever, from the familiar plucks of the guitar in the main theme to the newer compositions, which was a mixture of jazz, dreamy 50’s-esque pop music, and electronic ambiance. Sound plays such an important role in ‘Twin Peaks: The Return’ that viewers would really be missing out without a truly good sound system, and I am happy to report that the Focal Sopras easily qualifies as components for just such a system.

Focal Sopra N°1 Bookshelf & Center Speaker Measurements Conclusion

 

The Focal Sopra No1 bookshelf speaker and Center were measured in free-air at a height of 7.5 feet at a 1-meter distance from the microphone, and the measurements were gated at a 10-millisecond delay. In this time window, some resolution is lost below 250 Hz and accuracy is completely lost below 110 Hz. Measurements have been smoothed at a 1/12 octave resolution.

 

The above graph shows the direct-axis frequency response and other curves that describe the speakers’ amplitude response in a number of ways. For more information about the meaning of these curves, please refer to our article Understanding Loudspeaker Measurements Part 1. The above-measured performance is superb. The No1 Sopra boasts a terrifically neutral response on and off-axis. A few interesting points of interest: there is a slight on-axis boost in the highest audible treble region. This might give the speaker a bit more “air” if listened to dead on-axis. Off-axis, the tweeter does begin to beam slightly past 10kHz as many dome tweeters do when not installed in a waveguide. On the Sopra No1s, this is surprisingly mild though since we see little evidence of that in the ‘Listening Window’ curve and mostly in the ‘Early Reflections’ curve. This means that the beaming doesn’t really affect dispersion much out to a 30-degree angle off-axis. We do see an ever-so-slight directivity error where the tweeter’s dispersion is just a hair wider than that of the woofer at the crossover point, but this is very unlikely to be audible. Most two-way bookshelf speakers with a 1” dome with no waveguide and 6.5” woofer have a bit more significant directivity mismatch than we see here. This directivity is as good as I have ever seen for a speaker of this design type. We only show this ‘spin-o-rama’ style graph for the Sopra No1 bookshelf speaker since we aren’t able to capture the full circumference of the Sopra Center’s vertical response which is needed for this graph.

The above graphs depict the Sopra No1 bookshelf speaker’s lateral responses out to 90 degrees in five-degree increments. More information about how to interpret these graphs can be read in this article: Understanding Loudspeaker Review Measurements Part II. One thing we can see more clearly in this graph is the width of the dispersion and specific responses per angle. We can see that the Sopra No1 is a very wide dispersion loudspeaker all the way out to 10kHz, and its off-axis response corresponds beautifully to its on-axis response. This speaker can be listened to at any angle in the entire front semicircle of the tweeter’s height and it will sound good. If you want to hear those extremely high frequencies above 15kHz, you should stay within a 25-degree angle of the tweeter. However, there isn’t much content in that frequency band. Furthermore, most male adults over 30 have some high-frequency loss in that region, and if you are a male adult over 55, you are unlikely to have any significant hearing left in that band at all. We can see from these graphs that the most neutral response seems to be from ten to fifteen degrees, but that is only because of the rise of the on-axis response of the tweeter past 15kHz. This speaker has a neutral enough response that it could easily be used as a studio monitor if you wanted to record music and be sure that your loudspeakers are giving a faithful reproduction of the recording. That is all the more impressive coming from a passive loudspeaker; most studio monitors use all kinds of DSP equalization to achieve a flat response, but the Sopra No1 has an intrinsically flat response. This is an exceptionally accurate loudspeaker.   

Moving on to the Sopra Center, we can see that it doesn’t present as pristine of a response as the No1 bookshelf speakers, but it isn’t at all bad. It is a somewhat ragged response but the small peaks and dips adhere to a generally neutral response. Like the No1 bookshelf speakers, the dispersion is quite wide. One minor problem is that all of the little peaks and dips of those waves occur at different frequencies as you move off-axis, so any equalization done to one frequency range may exacerbate some response flaw at another angle. This speaker wouldn’t take well to fine EQ’ing, although it is flat enough that you could do broad EQing over a wide range like a tone control. I think that the overall response is neutral enough that it doesn’t need any assistance from equalization, except perhaps in lower frequencies where room modes dominate.

One nice thing to see in a center speaker is the absence of cancellation lobes from the bass drivers. The bass drivers are crossed over to the midrange driver at a low enough frequency so that the horizontal response isn’t squeezed by phase cancellation of the woofers fighting each other off-axis. That gives these speakers a much wider angle of coverage than typical MTM center speakers (Audioholics has discussed the matter at length in these articles: Vertical vs Horizontal Center Speaker Designs, Vertical vs Horizontal Center Speaker Designs - An Alternate Perspective, and Center Channel Speaker Design Additional Considerations). That is a relief to me because I would consider the horizontal dispersion pattern of a typical MTM center speaker to be unacceptable in the Sopra Center’s price range.

 

The above polar map graphs show the same information that the preceding graphs do but depict it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, these polar maps use color to portray amplitude and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s behavior more easily. For more information about the meaning of these graphs, we again refer the reader to Understanding Loudspeaker Review Measurements Part II. The polar map of the Sopra No1 bookshelf speaker puts up a good showing here with some interesting features. The first thing we can see is that this is a very wide dispersion speaker with off-axis energy that doesn’t really drop off much even out to 70-degrees. The dispersion is fairly uniform out to 10kHz with very slight waist-banding around the crossover frequency at 2.2kHz. The shape of the tweeter’s beaming above 10kHz is, as was mentioned before, better than normal for a tweeter lacking a waveguide. Even out to 20kHz, you still get a solid response past a 20-degree angle. That is abnormally good for a dome tweeter. Most dome tweeters have a laser-like beam at that frequency where you would need to be right on-axis to be hit with any real acoustic energy at all.

 

The Sopra center has a similar dispersion pattern to the No1 bookshelf speakers but there are differences. There are some visible irregularities within the dispersion, but nothing too erratic. There are some slight V-shaped nulls that move outward as frequencies rise. I am not sure what that is due to, perhaps some kind of baffle diffraction? The treble begins to narrow at slightly lower frequencies than the No1 bookshelf speaker. On the whole, this polar map shows good behavior. This center speaker will cover a wide area with a full sound. Those sitting way off-axis may miss a bit of high treble, but I don’t think that will be a big deal. The vast majority of people who listen to a system with this speaker will be sitting within a 25-degrees of the on-axis angle where they will be met with a strong signal that exceeds the best of human hearing in high-frequency extension.

 

The above graph shows the Sopra No1 bookshelf speaker’s response behavior along its vertical axis where zero degrees is directly in front of the tweeter, negative degree values are below the tweeter, and positive degree values are above the tweeter.  It should be said here that the vertical response isn’t nearly as critical as the horizontal response, so an imperfect vertical dispersion is much less of a problem. We can see that the on-axis response is the place to be with this speaker, as expected, but plus or minus ten degrees doesn’t change the response much. Past ten degrees in either direction, we do see some significant nulls form from the woofer and tweeter falling out of phase with each other. These speakers are best listened to at tweeter height, but there is some tolerance before major errors creep in the vertical dispersion response. One interesting thing to see is how narrow the crossover nulls are, and that indicates that the Sopra No1’s are using fairly steep crossover filters. The good news about that is acoustic reflections from vertical surfaces won’t deviate too severely from the on-axis sound, and the more that the acoustic reflections resemble the direct sound from the speaker, the better it is for the overall sound heard in-room.   

 

The above graphs show the Sopra No1 bookshelf speaker’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide-open area). Again, we see a nicely flat response from the Sopra No1. Port output gains the user a stronger response down below 50Hz but doesn’t seem to offer that much more output at a nominal drive level. The real advantage is the restricted excursion that the driver sees around port tuning frequencies, which means that the sound it does output will be far more linear. Focal specifies a -6dB point of 41Hz, and that doesn’t seem to be the case here. It looks to me that it would be closer to 50Hz. Nonetheless, this speaker does have usable bass below 50Hz, and it should capture almost all of the bass in conventional acoustic music save for certain genres like pipe organ recordings.

 

The Sopra Center’s low-frequency response isn’t quite as neutral as the No1 bookshelf speakers. There seems to be a high-Q hump centered around 175Hz. The bass on the Sopra Center may be slightly thick, although I didn’t notice anything like that in my listening. As with the No1 bookshelf speakers, the port gives it a solid response down to 50Hz. Automated EQing systems like Audyssey or Dirac probably make the elevated bass a non-issue since they tend to equalize the low-frequency response quite heavily. There is a lot of bass here, so sealing the ports might not be a terrible idea if the speaker is being placed on a shelf and near a back wall or especially in an entertainment center cavity.

 

The above graphs show the electrical behavior of the Sopra No1 bookshelf speakers. Focal rates this as an 8-ohm nominal load with a 3.9 minima. From 10Hz to 22kHz, I didn’t measure anything as low as 3.9 ohms. The impedance does touch 5 ohms in the mid-bass region. Overall there is nothing to worry about here even for budget amps, not that anyone is going to drive some Focal Sopras with a budget amp. The dip in the saddle indicates that the port tuning frequency is about 55Hz, and the even levels of the peaks around the saddle indicate that the port’s tuning is a very good match for both the enclosure and driver.

The Sopra center is a tougher electrical load than the No1 bookshelf speaker. I measured an impedance minima of 4.1 ohms in the widely used mid-bass region, and it’s interesting to note that is where we saw a wide hump in the response. Outside of the mid-bass region, there isn’t anything that could even slightly tax any competently made amplifier. The dip in the saddle just above 50Hz is revealed to be the port tuning frequency. The taller height of the first saddle indicates that the resonant frequency of the enclosure is higher than that of the driver. A cheap amp might struggle with the mid-bass impedance and phase of this speaker if played at high levels, but again, any amp this speaker is likely to be paired with will not have any problem with this electrical load.

I measured the Sopra No1 bookshelf sensitivity to be 87.8dB for 2.83v at 1 meter. That is a very close match for Focal’s own spec of 88dB for those same conditions. That is a pretty healthy sensitivity for a bookshelf speaker of its design and low-frequency extension. I measured the Sopra Center sensitivity to be 90.1dB for 2.83v at 1 meter. Again, not far from Focal’s own spec of 92dB. These are not low-sensitivity speakers, and they will get plenty loud for most people’s tastes without running into their maximum rated power handling. It also makes the Sopra’s center impedance minima less of an issue if you were planning on running that $4,000 center speaker with a $200 AVR amp.

Conclusion

I found the Sopra speakers to be more than just living room jewelry as many high-end audio products can be. They actually have the audio performance to back up their opulent looks and extravagant build quality. With that being said, I will now go over some of the pluses and minuses of the Focal Sopra speakers, and, as usual, I will start with the minuses. Their chief “minus” isn’t really a minus so much as it is a reality of a speaker of this type; it is rather expensive. However, there is no way for a speaker of this build quality, craftsmanship, and performance to be cheap, so I can’t fairly hold that against the Sopras. Nonetheless, the pricing precludes them from consideration from a great many people who are putting together audio systems.

The second “minus” that I see is that the Center speaker doesn’t quite have the near-perfect performance that the No1 bookshelf speakers do. To be sure, the Sopra Center isn’t bad, but its accuracy does not match that of its bookshelf speaker counterparts. It does have higher sensitivity and higher power-handling. For those who have the vertical space to accommodate another Sopra No1 as a center, that would be the best match for a front-stage LCR. Still, the Sopra Center is good, and my guess is that the difference between using that or another No1 bookshelf speaker as a center speaker wouldn’t be very noticeable. It’s also worth noting that the No1 bookshelf speakers are heavier and more expensive than the center speaker, which is an unusual situation among speaker lines. I would say if you don’t need the extra dynamic range of the Sopra Center, see if you can use the No1 bookshelf as a center. On the other hand, if you want an LCR set with a very healthy amount of dynamic range, a trio of Sopra Centers would be pretty darn good; they could work as left and right speakers very well since they aren’t hampered by the traditional directional/radiation problems of many center speaker designs.

Those are the only aspects of the Sopras that I see as drawbacks, and with that out of the way, let’s now get into their pluses, which are many. Firstly, I am a person who values the audio performance of a speaker first and foremost, and the sound that the Sopras produce is outstanding. The No1 bookshelf speakers produce an on-axis response that is near perfect. Going out to off-axis angles, all that is lost is high-treble that most listeners are unlikely to be able to hear anyway, but the superbly flat response remains the same. If you want ruthless accuracy from a passive loudspeaker, you have it. It is not an easy feat to achieve in a passive loudspeaker but Focal has done it in a two-way bookshelf speaker. Not only is the response immaculate, but it is also achieved with solid extension down to 50Hz as well as above-average sensitivity and a very friendly electrical load. From a performance perspective alone, this is an outstanding design.

Past the performance, there is the sheer build quality and craftsmanship of the speakers. They have a truly high-end feel and look. The No1 bookshelf speakers in particular are like boulders; these things are far more solid and heavy than any other bookshelf speaker I have dealt with. With care in their use and storage, these can and should be heirloom speakers that will last for decades. Yeah, they are pricey speakers, but when you have to handle these in person, you can understand their pricing.

The styling of the Sopra speakers is also on par with the performance and build quality. I don’t think pictures quite do them justice. They look gorgeous. The fit and finish are spectacular; again, the best I have seen in a review product to date. The only person who would object to the appearance of these would object to the appearance of any speaker. The Sopras would fit in just fine even in the most luxurious interiors.

It’s difficult to imagine a higher-end bookshelf speaker than these unless they were made out of solid gold, however, Focal does have the Diablo Utopia Colour Evo speakers (that name is a mouthful) that are near twice the cost. I have no idea what they could do beyond what these Sopra speakers can do. If you are looking for a truly high-end bookshelf and center speakers but don’t want to take the risk of getting something that could end up having bizarre performance like some of the more exotic brands, the Sopras are a safe bet. Their performance, build quality, and aesthetics are all commensurate with each other: absolutely first-rate.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Appearance
Treble Extension
Treble Smoothness
Midrange Accuracy
Bass Extension
Bass Accuracy
Imaging
Dynamic Range
Fit and Finish
Performance
Value