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Focal Sopra N°1 Bookshelf & Center Speaker Measurements Conclusion



No1 outdoor testing

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.

Sopra No1 Spin O Rama 

The No1 Sopra boasts a terrifically neutral response on and off-axis.

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.

Sopra No1 3D waterfall response

Sopra No1 2D waterfall response

This is an exceptionally accurate loudspeaker. 

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.   

Focal center 3D waterfall response

Focal center 2D waterfall response

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.

Sopra No1 Polar Map 

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.

Focal Sopra Center polar map 

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.

Sopra No1 3D waterfall vertical response 

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.   

Sopra No1 Low Frequency Response 

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.

Sopra Center Low Frequency Response 

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.

Sopra No1 Impedance 

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.

Sopra Center Impedance

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.


sopra no1 singleI 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.

From a performance perspective alone, this is an outstanding design.

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.

No1 and centerThose 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.

focal logo 2

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

  • StarStarStarStarStar — Excellent
  • StarStarStarStar — Very Good
  • StarStarStar — Good
  • StarStar — Fair
  • Star — Poor
Build QualityStarStarStarStarStar
Treble ExtensionStarStarStarStarStar
Treble SmoothnessStarStarStarStarStar
Midrange AccuracyStarStarStarStarStar
Bass ExtensionStarStarStarStar
Bass AccuracyStarStarStarStarStar
Dynamic RangeStarStarStarStar
Fit and FinishStarStarStarStarStar
About the author:

James Larson is Audioholics' primary loudspeaker and subwoofer reviewer on account of his deep knowledge of loudspeaker functioning and performance and also his overall enthusiasm toward moving the state of audio science forward.

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Recent Forum Posts:

MrMustard posts on July 19, 2021 17:37
Food for thoughts.
For the bi-amping, I just relied on the fact that both my amplifiers have the same gain (28dB).
However I agree with you since I recently bought a NAD M28 and it's great.
I still own my old Accuphase A-30, so I decided to keep on after trying both set-ups (perhaps just for a subtle touch of richness in the higher frequecies).
For the heat dissipation of class A amp, considering I live in canada, and mostly listen to music in colder temperature, it's not really an issue.
ryanosaur posts on July 15, 2021 19:36
MrMustard, post: 1494307, member: 96350
As far as I'm concerned, and if It was not for how you support them, I would buy a pair of Sopra centers. You get a 3-way pair with more base extension for 2k$ less. I don't get how they come up with their pricing.
I kindly disagree with the bi-amping option. Here's an examle; I use a good class D amp. for my woofer and a high end-low power pure class A amp. for my midrange & tweeter. That's where you can optimize such a set-up
I would not be too keen on spreading 6 Mid woofers out on the horizontal plane across my front wall, much less using Center Speakers with their limited F3 as mains. All of this points toward various performance concerns that just aren't worth the effort to deal with, IMO.
Not even trying to get into the Cost v. Performance conversation here, even though I feel strongly that high-quality, high-performance speakers can be had for less which will also function better in a room than risking a setup like that.
shadyJ posts on July 15, 2021 19:36
MrMustard, post: 1494307, member: 96350
As far as I'm concerned, and if It was not for how you support them, I would buy a pair of Sopra centers. You get a 3-way pair with more base extension for 2k$ less. I don't get how they come up with their pricing.
I kindly disagree with the bi-amping option. Here's an examle; I use a good class D amp. for my woofer and a high end-low power pure class A amp. for my midrange & tweeter. That's where you can optimize such a set-up
The Sopra Centers are not quite as overbuilt as the Sopra bookshelf speakers. The Sopra Centers do not have the aluminum compartment that eliminates the backwaves from the tweeter. The Center doesn't have the glass top either. The weight between the center and the bookshelf speaker is about the same. The center's only advantage is greater dynamic range owed to the three-way design and two woofers. In every other way, the Sopra No1 is the better speaker. Not to say the center is a bad speaker, it's a good speaker, and a front stage of three of them would be a nice setup indeed.

As for bi-amping, you are more likely to screw things up than improve anything. You would need some pretty careful measurements to level match the tweeter to the woofer. Do you have the measurement gear and expertise to do that? Do you know what that would look like as an in-room measurement? It might not be as obvious as you think. Also, Class A's advantages over Class D is long gone with the advent of newer class D topologies. No class A amp can match the accuracy of Benchmark's AHB2 or Purifi's modules. Class A's main advantage is savings on heating bills in colder climate living.
Hubbard32 posts on July 15, 2021 19:24
MrMustard, post: 1494307, member: 96350
As far as I'm concerned, and if It was not for how you support them, I would buy a pair of Sopra centers. You get a 3-way pair with more base extension for 2k$ less. I don't get how they come up with their pricing.
I kindly disagree with the bi-amping option. Here's an examle; I use a good class D amp. for my woofer and a high end-low power pure class A amp. for my midrange & tweeter. That's where you can optimize such a set-up
I'll admit, it would be interesting to hear three of the Sopra centers across the front to see what that sounds like..
If anyone ever takes this on, I'd love to know if the results were positive.
MrMustard posts on July 15, 2021 16:04
As far as I'm concerned, and if It was not for how you support them, I would buy a pair of Sopra centers. You get a 3-way pair with more base extension for 2k$ less. I don't get how they come up with their pricing.
I kindly disagree with the bi-amping option. Here's an examle; I use a good class D amp. for my woofer and a high end-low power pure class A amp. for my midrange & tweeter. That's where you can optimize such a set-up
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