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Focal SOLO6 ST6 Monitor Review

Rate this monitor speaker:

  • 1. Poor (headless panther)

    Votes: 2 0.8%
  • 2. Not terrible (postman panther)

    Votes: 43 18.2%
  • 3. Fine (happy panther)

    Votes: 149 63.1%
  • 4. Great (golfing panther)

    Votes: 42 17.8%

  • Total voters
    236
I heard the previous generation
I feel the Beryllium tweeter has a unique sound , very different from Neumann and Genelec .
What do you mean by "unique" sound ? Can you explain your more precisely and objectively what differences does it make ?
And which type of sound do you prefer ? the Genelec/Neumann or the Focal.
As for me, I always appreciated quite a lot the sound of all the Genelecs i've heard (didn't listened to Neumam yet), but I appreciated very much too theSM9 Focal monitor, and the previous generation of their Twin 6.

Difficult to be sure which one I would have in my home. For sheer neutralty and flexibility, Genelec or Neumann come first, but for good looks and quality performance in a domestic perspective, Focal come first.
 
Let's just be honest. Where a previously established brand moves some production/manufacture to China, it is done for monetary reasons. People in the original country lose their jobs, livelihood, factories become derelict and sometimes entire town/areas economies can collapse. It's not pretty.

I'd rather buy a Focal made in France. That's just me.

Just consider all the classic British HiFi brands that have been sucked up into conglomerates and are now just badges. I look at the back of my UK made speakers and wonder what happened to those world class factories and their hard working employees when their company was 'aquired'.

I just bought a new Kitchenaid stand mixer and it's proudly still made in the USA. Why? Because it's built the way I like stuff to be built, in a 100+ year old company employing Americans in Greenville Ohio.

My money, my choice.
Spot on, John. Eventually if we don’t change our buying habits, we will kill our own industries. It's a race to the bottom. Happy to see the latest Buchardt anniversary speaker being built in Denmark. Genelec and Neumann, what great companies. Speaking of great sound, your Kitchenaid too is examplary. It’s our super solid bread-and-butter darling in the kitchen.
 
What do you mean by "unique" sound ? Can you explain your more precisely and objectively what differences does it make ?
And which type of sound do you prefer ? the Genelec/Neumann or the Focal.
As for me, I always appreciated quite a lot the sound of all the Genelecs i've heard (didn't listened to Neumam yet), but I appreciated very much too theSM9 Focal monitor, and the previous generation of their Twin 6.

Difficult to be sure which one I would have in my home. For sheer neutralty and flexibility, Genelec or Neumann come first, but for good looks and quality performance in a domestic perspective, Focal come first.
It's hard to describe
It's like it's hyper detailed or something compared to the Neumann and Genelecs
The highs sound super sharp, like a knife in your ear( in a positive way)
The Neumanns sound dark compares to it
Genelecs just sound neutral , you don't noticed the highs sticking out at all
 
It is a good monitor but not as good as the Neumann KH 150. The KH 150 really set a new standard which is very hard for any other monitor to live up to.
 
It's hard to describe
It's like it's hyper detailed or something compared to the Neumann and Genelecs
The highs sound super sharp, like a knife in your ear( in a positive way)
The Neumanns sound dark compares to it
Genelecs just sound neutral , you don't noticed the highs sticking out at all
That is because the Neumann frequency response curve is flat and does not color the sound.
 
It's hard to describe
It's like it's hyper detailed or something compared to the Neumann and Genelecs
The highs sound super sharp, like a knife in your ear( in a positive way)
The Neumanns sound dark compares to it
Genelecs just sound neutral , you don't noticed the highs sticking out at all
I mean... This is pretty obvious that there's a huge amount of excess presence and treble in room. That's not a beryllium thing, that's a Focal thing.

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That is because the Neumann frequency response curve is flat and does not color the sound.
Not... really. It's more the off-axis behavior that's doing it here. Neumann has pretty narrow controlled dispersion once they become directional, just as a general rule - the widest is the KH310, and it's only got a beamwidth of about 55 degrees. The others are much narrower. Genelec trends slightly wider, about 55-60 degrees, so they trend a little bit brighter in room.
 
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I never found the Focal pro monitors I've listened to (the SM9 and the Twin 6 V1) ear bleeding nor even too bright, compared to many hifi speakers, including some Focal ones. "Sharp" and precise, yes, but not in a caricatural way. Maybe the new generation is less neutral in the high medium/low treble than the previous ones ? If so, that wouldn't be an improvement, better find an old used one (for price too, of course).

The Genelecs are not bright too, and the dispersion of The Ones is particularly coherent from 400 hz or so to the extreme treble. I partularly appreciate this, it gives a very natural reproduction and the sweet spot is indeed larger compared to usual near or midfield monitors, and obvious advantage of a coaxial driver done right.

I never listened to any Neumann yet, I shoud do it, I know. They're obviously very good, ultra neutral and with very little distorsion and a wide FR in the low end for their size, but they're focused on pure monotoring/post production, they're working tools by excellence (Genelecs too, but they're probably a bit more versatile and make slowly their way in domestic use). I also know people who find the Neumanns a bit too dull and narrow for pure listening pleasure, and others who love them, including for pleasure. I have to make my own opinion.
 
Somehow it looks significantly uglier and cheaper than Solo 6 Be. Same goes for new Alpha (Evo?) as well IMO.
No doubts that sound is great especially if AudioQuest wires are used
 
I know Genelec and Neumann are the standard around here, but I've always eyed the Focals for their more "designed" looks. So it's good to see they perform well.
 
I know Genelec and Neumann are the standard around here, but I've always eyed the Focals for their more "designed" looks. So it's good to see they perform well.
It is, back before I made my purchase decision a few years ago I struggled between the shape 50 vs 8030C since I really liked focal’s design look and their driver looks! Ended up buying for standard and no regret but absolutely be happy if they are close in performance. But sadly it seems the old solo 6 be performs better in terms of directivity and predicted in room response than this new model..

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IMG_5817.png
 
It's like it's hyper detailed or something compared to the Neumann and Genelecs
The highs sound super sharp, like a knife in your ear( in a positive way)
I mean... This is pretty obvious that there's a huge amount of excess presence and treble in room. That's not a beryllium thing, that's a Focal thing.
We can even easily determine what in detail is responsible for the very wide radiation of the Solo6 ST6 in the 4-9 kHz range.

For this purpose, we compare a "normal" convex dome, a concave/inverse dome and a concave/inverse dome with an additional "step" in the baffle by simulating the tweeters in an infinite baffle. It's always the exact same dome with identical TSP only difference is convex or concave mounting.

Sketches (side view) of simulated "ideal" (no break-up resonances) tweeters (last one with "step" in the baffle. Roughly like the Solo6 ST6)
1687477170059.png 1687477184389.png 1687477195989.png

Now we compare the resulting normalized FR from 0°-80° (10° steps):
1687477915510.png 1687477929565.png 1687477945048.png
It can be seen that the inverse dome radiates slightly less broadly than the "normal" convex dome.
To significantly widen the radiation of the Focal inverse dome, the "step" was integrated into the baffle.
1687478265834.png
This simple "flat waveguide" is all it takes to allow a wide radiation up to 9-10khz.

How dramatic the differences in the radiation are, can also be seen very well if you compare the sound pressure level sonograms at 7kHz without and with "baffle step waveguide":
1687587382528.png 1687587407918.png

For comparison with reality, here are the normalized horizontal frequency response measurements (0°, 20°,...80°) of the Solo6 ST6 from Amir's NFS:
1687479190339.png
Shows a very similar radiation pattern in the 4-10kHz range like our simple simulation with an ideal dome tweeter.
 
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I never found the Focal pro monitors I've listened to (the SM9 and the Twin 6 V1) ear bleeding nor even too bright, compared to many hifi speakers, including some Focal ones. "Sharp" and precise, yes, but not in a caricatural way. Maybe the new generation is less neutral in the high medium/low treble than the previous ones ? If so, that wouldn't be an improvement, better find an old used one (for price too, of course).

The Genelecs are not bright too, and the dispersion of The Ones is particularly coherent from 400 hz or so to the extreme treble. I partularly appreciate this, it gives a very natural reproduction and the sweet spot is indeed larger compared to usual near or midfield monitors, and obvious advantage of a coaxial driver done right.

I never listened to any Neumann yet, I shoud do it, I know. They're obviously very good, ultra neutral and with very little distorsion and a wide FR in the low end for their size, but they're focused on pure monotoring/post production, they're working tools by excellence (Genelecs too, but they're probably a bit more versatile and make slowly their way in domestic use). I also know people who find the Neumanns a bit too dull and narrow for pure listening pleasure, and others who love them, including for pleasure. I have to make my own opinion.

We can even easily determine what in detail is responsible for the very wide radiation of the Solo6 ST6 in the 4-9 kHz range.

For this purpose, we compare a "normal" convex dome, a concave/inverse dome and a concave/inverse dome with an additional "step" in the baffle by simulating the tweeters in an infinite baffle. It's always the exact same dome with identical TSP only difference is convex or concave mounting.

Sketches (side view) of simulated tweeters (last one with "step" in the baffle. Roughly like the Solo6 ST6)
View attachment 294276 View attachment 294277 View attachment 294278

Now we compare the resulting normalized FR from 0°-80° (10° steps):
View attachment 294281 View attachment 294282 View attachment 294283
It can be seen that the inverse dome radiates slightly less broadly than the "normal" convex dome.
To significantly widen the radiation of the Focal inverse dome, the "step" was integrated into the baffle.
View attachment 294288
This simple "flat waveguide" is all it takes to allow a wide radiation up to 9-10khz.

How dramatic the differences in the radiation are, can also be seen very well if you compare the sound pressure level sonograms at 7kHz without and with "baffle step waveguide":
View attachment 294289 View attachment 294290

For comparison with reality, here are the normalized horizontal frequency response measurements (0°, 20°,...80°) of the Solo6 ST6 from Amir's NFS:
View attachment 294299
Shows a very similar radiation pattern in the 4-10kHz range like our simple simulation with an ideal dome tweeter.
It's a coincidence Becaue I've watched this a few days ago
 
We can even easily determine what in detail is responsible for the very wide radiation of the Solo6 ST6 in the 4-9 kHz range.

For this purpose, we compare a "normal" convex dome, a concave/inverse dome and a concave/inverse dome with an additional "step" in the baffle by simulating the tweeters in an infinite baffle. It's always the exact same dome with identical TSP only difference is convex or concave mounting.

Sketches (side view) of simulated tweeters (last one with "step" in the baffle. Roughly like the Solo6 ST6)
View attachment 294276 View attachment 294277 View attachment 294278

Now we compare the resulting normalized FR from 0°-80° (10° steps):
View attachment 294281 View attachment 294282 View attachment 294283
It can be seen that the inverse dome radiates slightly less broadly than the "normal" convex dome.
To significantly widen the radiation of the Focal inverse dome, the "step" was integrated into the baffle.
View attachment 294288
This simple "flat waveguide" is all it takes to allow a wide radiation up to 9-10khz.

How dramatic the differences in the radiation are, can also be seen very well if you compare the sound pressure level sonograms at 7kHz without and with "baffle step waveguide":
View attachment 294289 View attachment 294290

For comparison with reality, here are the normalized horizontal frequency response measurements (0°, 20°,...80°) of the Solo6 ST6 from Amir's NFS:
View attachment 294299
Shows a very similar radiation pattern in the 4-10kHz range like our simple simulation with an ideal dome tweeter.
This somehow sounds to me like: it’s a almost perfect dome tweeter, but we invert it and compensate the radiation beamwidth so it now have a chewed up highs signature
 
Convex or concave dome doesn't mean anything, sorry for the supposed scientific graphs posted over here, a complex "demonstration" that doesn't demonstrate anything. I heard the SM9 with their Be tweeter and I can tell you this is a really super fine and good tweeter, with no harshness at all ! And the "waveguide" in the new Focal ST6 isn't really a waveguide, i don't think it makes that much an effect on sound response listened and measured at 0 degree, maybe just a little bit at 30 degrees (and moreover I find this sighly recessed tweeter position unesthetic).

So the explanation for the excess of level in the 3 to 5 Khz zone is elsewhere : most probably in the new filtering design and in increased resonance of the boomer compared to the older version. The real question is : was it designed on purpose to give a more flattering treble ? I have no doubt the Focal engineers and technicians can design a flat FR, state of the art monitor, so my guess is that this was made on purpose. Nowadays, a lot of professionnals like a littel flattering sound, espacally in the rock/pop.hip hop domain. this flashy bright sound fashion has polluted the pro sphere itself.

that's why, all in all, the older version seems better, expect maybe for dynamics, and its looks are simpler, I like it better.
I'm french, I have a great respect for Focal competence, but I can't see any real improvement in tems of accuracy in the new 6 series, it makes me feel disappointed.

So, my advice if you value accuracy and neutrality in sound and want a pair of good enginereed and good looking monitor: go for a pair of the good original Focal 6 Be and forget the new Focal ST6. Simpler more elegant looks (IMHO), more even FR and of course a lot cheaper if you buy them thru a discounted old stock or good second hand.
 
And the "waveguide" in the new Focal ST6 isn't really a waveguide, i don't think it makes that much an effect on sound response listened and measured at 0 degree, maybe just a little bit at 30 degrees (and moreover I find this sighly recessed tweeter position unesthetic).
How we label the recessed position of the tweeter is not relevant, what matters is the effect on the radiation of the loudspeaker - because of the effect I would simplistically call it "flat WG".

If you don't design loudspeakers that often, you might think that such a small step on the baffle has no influence on the radiation/directivity or on-axis FR of the loudspeaker, but even such small "obstacles" influence the radiation by interference. Even protruding screws influence the radiation.

The effects on the on-axis frequency response, as with all WG/Horns, are usually greatest there. Here is the comparison of the on-axis FR of a inverse 1'' dome on an infinite baffle, once with and without the "flat WG" (in the simulation the WG has a circular shape with a 4mm step, in the ST6 the vertical radiation is slightly different due to the non-circular shape and I don't know the exact dimesions, hence the slight deviantions in the simulation):
1687510269301.png

In the range 3-9kHz the directivity changes from evenly increasing to constant.
1687511334802.png
Because of the "flat WG" the directivity is almost constant in the range 3-9kHz. If now additionally the on-axis dip, caused by the "flat WG", is corrected (to flat) by EQ, it comes to a clearly sound power increase in this frequency range - this is exactly what Amir's measurements show.


So the explanation for the excess of level in the 3 to 5 Khz zone is elsewhere : most probably in the new filtering design and in increased resonance of the boomer compared to the older version.
The crossover frequency should be in the range of 2.3-2.5kHz for the Solo6 ST6. Around this frequency range, the radiation/directivity of the speaker can be influenced by the filter. But already above 4kHz, with a fourth order filter, the radiation/directivity is almost no longer influenced by the filter.
1687512500141.png


The real question is : was it designed on purpose to give a more flattering treble ?
This is definitely a deliberate design and not the first time Focal has used a tweeter in a recessed position ("flat WG").
Whether this leads to a particularly flattering sound in the highs is something everyone has to decide for themselves.
 
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It is possible this flat "sort of" WG has more impact than I thought, your simulation seems relevant on that point.

As for the filtering, I don't follow you completely. If you look the measurments by Amir, the boost starts just at 3 Khz, so a 2,2 or 2,5 Khz/ 4th order filter is just below the boosted region, so I think the response in the 3/4 khz can be influenced by a filter designed to produce some boost, which a simulation can't predict as well as a directivity simulation. And this is approximately the same frequency region where measurements show a strong and curious resonance of the woofer, this adding to a global boost in FR.

I follow you completely when you assume this is a deliberate design. This was my guess , too.
Of couse, in the end all is a matter of personal taste, I will never blame someone who prefer a slightly "bright" speaker, but as for me, the older and flatter design suits me better, I am somehow an old fashioned european guy.
 
As for the filtering, I don't follow you completely. If you look the measurments by Amir, the boost starts just at 3 Khz, so a 2,2 or 2,5 Khz/ 4th order filter is just below the boosted region, so I think the response in the 3/4 khz can be influenced by a filter designed to produce some boost, which a simulation can't predict as well as a directivity simulation. And this is approximately the same frequency region where measurements show a strong and curious resonance of the woofer, this adding to a global boost in FR.
The widening of the radiation in the range 1.5-4kHz is mainly caused by edge diffraction.
This is of course not included in my simulation of the tweeter on infinite baffle (To take this into account, a simulation of the drivers in the cabinet would have to be performed - I don't have the time for this effort at the moment).

The tweeter interacts more with the side edges of the cabinet than the woofer, where the cone acts as a WG at these frequencies ("woofer beaming").

The crossover frequency determines whether the widening in the radiation is stronger (low crossover frequency, radiation in the range 1.5-4kHz is dominated by the tweeter) or weaker (high crossover frequency, radiation in this range is dominated by the woofer).
Of course, the filter itself cannot change the directivity of the drivers in the speaker cabinet, only their interaction.

Here I have roughly drawn the frequency ranges in Amir's horizontal measurements of the Solo6 ST6, where the various effects (edge diffraction, "flat WG") are probably dominant.
Once in the normal frequency response graph and once in the frequency response graph normalized to the on-axis frequency response (there you can see the effects better):
1687530385345.png 1687530412873.png
 
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