Radiant Acoustics Clarity 66 Speaker Review

[beeface]

That would be my ideal speaker.

External electronics with one amp to control one drive, all orchestrated and controlled by an DSP.

JBL's M2 system is a good blueprint.

As a non-DIYer, it would be cool to see a similar, commercially available system based on MiniDSP, Purifi amps, Purifi drivers and optional subwoofers.
The MiniDSP could be preconfigured with basic crossover settings as a default starting point to make it less intimidating for customers.

 

[jhaider]

You can always make the amp+DSP external.

Agree. That (I phrased it “active with remote amplification”) is the way I think it should be for serious active speakers.

 

[Maiky76]

This is a review, listening tests and detailed measurements of the Radiant Acoustics Clarity 66 Purifi-based speaker. It was sent to me by the company and costs US $9998 (a pair).
View attachment 547408
My sample is in black (please don't mind the poor white balance) and looks quite elegant. It also comes in walnut and oak finishes. Despite its modest size this is one heavy speaker! It weighs in at 46 KG or 88 pounds. I felt every bit of it as I moved the darn thing around.

Back panel sports the largest port I have seen in a domestic speaker:
View attachment 547409
It is almost the same size of the woofers! Under load, it pumps out fair amount of air.

The only binding post configuration offered is banana jacks, giving the back a very flat and finished look. I suggest getting locking ones.

The main actor here is not one but two Purifi drivers which are known for their low distortion. Despite its size, speaker is 2-way which I much prefer to 2.5 way we typically see.

Radiant Acoustics Clarity 66 Measurements
Let's start with our anechoic CEA-2034 frequency response measurements:
View attachment 547410
Response is generally flat with some localized peaks and resonances. They are quite narrow though so should not be very audible. There is a slight tilt up as I have shown with the arrow. Tweeter does have some pronounced resonances and roll off before 20 kHz. I should note that its design created a complex soundfield which was not fully resolved off-axis with the number of points I used to measure. The fins in front of it are the likely culprit.

Early window response shows a dip around crossover frequency (2.4 kHz):
View attachment 547411

I will show the pinched vertical directivity which is the guilty party:
View attachment 547412

The sum total looks alright though:
View attachment 547413

Near-field response shows the issues mentioned regarding tweeter:
View attachment 547414

Junk coming out of the port is nicely controlled.

Horizontal directivity is not very even:
View attachment 547415
View attachment 547416

So some room dependency may exist.

Now we get to the main act: distortion, or I should say lack thereof:
View attachment 547417
Amazing how the graph at 86 dBSPL hugs the near zero line, even in deep bass!!! It still remains civil at 96 dBSPL. During the sweeps, I only heard some deep bass distortion at 101 dBSPL. Below it sounded very clean.
View attachment 547418
I don't think I have seen distortion this low at 86 dBSPL.

Our new measurement of low frequency distortion shows off this capability like nobody's business:
View attachment 547419

We are talking less than 1% distortion in bass frequencies at even 91 dBSPL!

Impedance is typical at minimum of 4 ohm:
View attachment 547420

Waterfall shows a couple of resonances:
View attachment 547421

The 300 to 500 Hz was visisible in on axis response.

Step response is clean but has some waviness toward the end:
View attachment 547422


Radiant Acoustics Clarity 66 Speaker Listening Tests
The first impression was how low the bass response went and importantly, how clean it was. I have never heard a speaker with a couple of small drivers reproduce my sub-bass tracks as if it was a walk in the park! It might be subjective bias but track after track seemed to have more bass than I remember with cleaner reproduction.

As for tilted up highs, my ears are plugged from mowing our dusty field. But I could not detect excessive treble response. I sensed speaker was activating some of my room modes which may have balanced the response out.

With the amplification I was using, I was not able to create audible distortion even at max volume. And this is a very large space with a single speaker.

Conclusions
What do you get when you have the designer of one of the most advanced woofers get involved in a full speaker design? Clarity 66. We are talking about a full range speaker with unheard of distortion levels, doing justice to its name in that region. Yes, it has kind of a cliff that sets in at 101 dBSPL but below that, it likely beats any speaker its size and by wide margin.

Rest of the measurements are good to very good. Slight imperfections are seen here and there which seem to bother the eye more than the ears. For me anyway.

Price is high but we are talking about a speaker produced in Denmark. With luxury fit and finish and robust build. Very robust build.

The Clarity 66 brings true innovation and outside of the box thinking to speaker design. Certainly a feather in the cap of our Danish friends!

I am happy to recommend the Radiant Acoustics Clarity 66.
-----------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Here is my take on the EQ.
Please report your findings, positive or negative!

For the score rational your journey starts here
Explanation for the sub score
The following EQs are “anechoic” EQs to get the speaker right before room integration.
If you able to implement these EQs you must add EQ at LF for room integration, that is usually not optional… see hints there.

The raw data with corrected ER and PIR:

Score no EQ: 5.2
With Sub: 7.1

Spinorama with no EQ:

• Not smooth poor vertical directivity
• a few resonances
• HF ragged
• Ascending LW

Directivity:

Better stay at tweeter height
Horizontally, better toe-in the speakers by 10/15deg and have the axis crossing in front of the listening location, might help dosing the upper range. Explanation here.

EQ design:
I have generated two EQs. The APO config files are attached.

• The first one, labelled, LW is targeted at making the LW flat
• The second, labelled Score, starts with the first one and adds the score as an optimization variable (here).
• The EQs are designed in the context of regular stereo use i.e. domestic environment, no warranty is provided for a near field use in a studio environment although the LW might be better suited for this purpose.
• One can model the EQ with Vituixcad by using the DSP "Generic" setting with 96000Hz sampling rate.
• Just Score EQ as it is essentially the same as LW

Score no EQ: 5.2
With Sub: 7.1

Score EQ Score: 6.6
with sub: 8.3

Radiant Acoustics 66 APO Score EQ 96000Hz
July282026-121718

Preamp: -3.00 dB

Filter 1: ON HPQ Fc 34.9 Hz Gain 0.00 dB Q 1.31
Filter 2: ON PK Fc 568.5 Hz Gain -2.06 dB Q 6.00
Filter 3: ON PK Fc 918.5 Hz Gain -2.29 dB Q 5.50
Filter 4: ON PK Fc 1000.1 Hz Gain 1.88 dB Q 0.88
Filter 5: ON PK Fc 1548.4 Hz Gain -0.31 dB Q 6.00
Filter 6: ON PK Fc 5612.9 Hz Gain -0.96 dB Q 2.97
Filter 7: ON PK Fc 6759.2 Hz Gain 2.12 dB Q 4.15
Filter 8: ON PK Fc 8207.1 Hz Gain -2.41 dB Q 4.94
Filter 9: ON PK Fc 10760.7 Hz Gain 2.33 dB Q 3.16
Filter 10: ON PK Fc 12152.6 Hz Gain -2.42 dB Q 3.07

Spinorama EQ Score

Zoom PIR-LW-ON

Regression - Tonal

Radar no EQ vs EQ score
Some improvements?

 

[pma]

Can you please show this graph using dB rather than %? The mental math of converting one to the other takes away from my pleasurable contemplation of the numbers.

….. better say in logarithmic Y scale rather than the linear used. To get more visible resolution at lower distortion level.

 

[Power Pop 23]

Thank you for this review,

Would you care to explain the reasons why?

Per Amir in post #10 of this thread.

2.5 ways make a huge mess around crossover region with a ton of waveforms interfering.

 

[capslock]

@Lars Risbo Thank you for explaining about the transmission line / bass port and the AMT crossover. Could you please elaborate on the choice of paper cone for the 6.2 vs aluminum for the 66 for the same waveguide and presumably the same AMT driver? Thanks

 

[pathtonowhere]

The horrible vertical dispersion would be a deal breaker for me. I wouldn't accept it for a 1k speaker, let alone a 10k speaker. I too think a 2.5 way configuration would have been much better. Yes, there are some disadvantages for the 2.5 way speakers too, but a 2 way with 2 woofers is really the worst of the worst. There's a reason the vast majority of 2 woofer speakers are 2.5 way, not 2 way.

 

[SigbergAudio]

These review threads are an interesting read as always. Apparently many find it expensive, I think it's pretty reasonable.

Also, I'm baffled that people don't think it measures well. No speaker is perfect of course, but surely this is a pretty well designed speaker?

 

[Gremlins]

Here is my take on the EQ.
Please report your findings, positive or negative!

For the score rational your journey starts here
Explanation for the sub score
The following EQs are “anechoic” EQs to get the speaker right before room integration.
If you able to implement these EQs you must add EQ at LF for room integration, that is usually not optional… see hints there.

The raw data with corrected ER and PIR:

Score no EQ: 5.2
With Sub: 7.1

Spinorama with no EQ:

• Not smooth poor vertical directivity
• a few resonances
• HF ragged
• Ascending LW

View attachment 547589
Directivity:

Better stay at tweeter height
Horizontally, better toe-in the speakers by 10/15deg and have the axis crossing in front of the listening location, might help dosing the upper range. Explanation here.
View attachment 547596View attachment 547603

EQ design:
I have generated two EQs. The APO config files are attached.

• The first one, labelled, LW is targeted at making the LW flat
• The second, labelled Score, starts with the first one and adds the score as an optimization variable (here).
• The EQs are designed in the context of regular stereo use i.e. domestic environment, no warranty is provided for a near field use in a studio environment although the LW might be better suited for this purpose.
• One can model the EQ with Vituixcad by using the DSP "Generic" setting with 96000Hz sampling rate.
• Just Score EQ as it is essentially the same as LW

View attachment 547594
Score no EQ: 5.2
With Sub: 7.1

Score EQ Score: 6.6
with sub: 8.3

Radiant Acoustics 66 APO Score EQ 96000Hz
July282026-121718

Preamp: -3.00 dB

Filter 1: ON HPQ Fc 34.9 Hz Gain 0.00 dB Q 1.31
Filter 2: ON PK Fc 568.5 Hz Gain -2.06 dB Q 6.00
Filter 3: ON PK Fc 918.5 Hz Gain -2.29 dB Q 5.50
Filter 4: ON PK Fc 1000.1 Hz Gain 1.88 dB Q 0.88
Filter 5: ON PK Fc 1548.4 Hz Gain -0.31 dB Q 6.00
Filter 6: ON PK Fc 5612.9 Hz Gain -0.96 dB Q 2.97
Filter 7: ON PK Fc 6759.2 Hz Gain 2.12 dB Q 4.15
Filter 8: ON PK Fc 8207.1 Hz Gain -2.41 dB Q 4.94
Filter 9: ON PK Fc 10760.7 Hz Gain 2.33 dB Q 3.16
Filter 10: ON PK Fc 12152.6 Hz Gain -2.42 dB Q 3.07

Spinorama EQ Score
View attachment 547590

Zoom PIR-LW-ON
View attachment 547593

Regression - Tonal
View attachment 547592

Radar no EQ vs EQ score
Some improvements?
View attachment 547591

Thanks
I just don't understand why the company doesn't design their xover right at first so that it score high directly?

 

[mv8]

would be nice but active speakers are sadly not an easy sell to the hifi market. they eliminate expensive cables and several other electronics boxes. somehow consumers don’t value all the electronics inside active speakers

As long as vinyl records are still in use, their enthusiasts will be resistant to putting DSP-equipped active speakers into a completely analog signal path. That’s why I think that in the high-end world, active systems with DSP won’t be popular for a long time to come. Only active systems with analog crossovers have gained some acceptance.

 

[markstein]

As long as vinyl records are still in use, their enthusiasts will be resistant to putting DSP-equipped active speakers into a completely analog signal path. That’s why I think that in the high-end world, active systems with DSP won’t be popular for a long time to come. Only active systems with analog crossovers have gained some acceptance.

I listen to vinyl through a Waxwing DSP phono pre, and the phono signal goes 100% digitally to my active loudspeakers which perform D/A conversion after their internal DSP. I might not be representative for the "high end" crowd though...

 

[Sjkrabbe]

Are we going to see reviews of the Clarity 4.2 and 6.2 here? They only have a single woofer and cost considerably less, enough for a high quality sub. There's still money wasted on those passive radiators. This is something Ascilab got right, offering a CB version.

The Clarity 6.2 might sport the same AMT and waveguide as the 66, the 4.2 has a smaller AMT with a mini waveguide.

edit: I take that back. The 66 has some vertical lamellae, sort of a linear version of the tangerine waveguide, that the 6.2 does not have,

Yeah - I hope to see those two speakers tested here by Amir, Through my work I had the VERY BIG pleasure to hear the putify prototype of the 6.2 before it came to be comercially available. Lars was showing it to me and some fellow soundengineers at DR - And I can easily claim that it was one of the best listening experiences I have ever had - And I have had MANY in my years of working in that field

 

[Lars Risbo]

@Lars Risbo Thank you for explaining about the transmission line / bass port and the AMT crossover. Could you please elaborate on the choice of paper cone for the 6.2 vs aluminum for the 66 for the same waveguide and presumably the same AMT driver? Thanks

the alu version has higher moving mass which enables more bass extension. Also, the alu version has even lower distortion but a higher Q cone break up around 5kHz. However, we handle that in the filter including suppressing the distortion rise from the peak (see https://purifi-audio.com/blog/app-notes-2/low-distortion-filter-for-ptt6-5x04-naa-11).

 

[Sjkrabbe]

I see that these use AMT tweeters. I remember hearing those many, many years ago and being very impressed; I didn't know they were still around. Just wondering about the bass-midrange: is it better to have 2 smallish wide-range drivers or larger bass and smaller mid? Is it just about having a nice, narrow cabinet? Anyway, I'd guess that these are hard to beat for £7k.

there is a lot of (mostly) european speaker maker that use AMTs: ADAM, FLUID, EVE, RADIANT, HEDD etc.

 

[Sjkrabbe]

As long as vinyl records are still in use, their enthusiasts will be resistant to putting DSP-equipped active speakers into a completely analog signal path. That’s why I think that in the high-end world, active systems with DSP won’t be popular for a long time to come. Only active systems with analog crossovers have gained some acceptance.

I use the Audient Oria Mini Room correction unit in my home setup - until further notice I keep my passive B&W 805 Matrixes. But I think - when someday I have to get new speakers - I will go for active ones - So I hope that Risbo and Radiant will get into the Active speaker market someday

 

[Enthusiastic Amateur]

That would be my ideal speaker.

External electronics with one amp to control one drive, all orchestrated and controlled by an DSP.

Yes.

Ideally the external DSP electronics would conform to a standard. So the manufacturer of the speaker only needs to provide a file with the DSP settings.

That way speaker manufacturers don't have to be electronics experts.

More importantly for us consumers, when part of the electronics stops working and there are no longer any repair options, we can simply buy another DSP box, or another multi-channel DAC, or another multi-channel amplifier. We won't have to throw away absolutely everything (both speakers, both DSP and both amps), the majority of which is still in perfect working order.

I speak from painful experience. I recently had to bin everything when the surface mount electronics of just one of a pair of excellent active studio monitors stopped working just three years after I bought them. (The manufacturer gave me a generous deal on replacements, but it still hurts me to throw good equipment away.)

For no added cost, users could use standards-compliant free software to edit a copy of the manufacturers DSP settings file to adjust the frequency response to their taste, or to their room.

 

[totti1965]

"We-want-more! We-want-more! We-want-more! We-want-more! We-want-more!
Speaker-Tests....."

... and not only by Erin!

 

[DanielT]

Thanks for this review, Amir. Speakers are the most interesting things you test, so this review is especially welcome.

Fascinatingly low distortion, and I agree with @Sigberg Audio on this point:

These review threads are an interesting read as always. Apparently many find it expensive, I think it's pretty reasonable.

Also, I'm baffled that people don't think it measures well. No speaker is perfect of course, but surely this is a pretty well designed speaker?

View attachment 547623

_____

I saw a comment asking why larger bass woofers aren't used. But for commercial reasons, not every speaker can feature massive 15- or 18-inch woofers. Not everyone wants those huge, wide speakers—three-way models with massive woofers. These days, I tend to view refrigerator-sized speakers more as DIY projects.

OT
Apart from a few high-end models from JBL and, say, Klipsch—correct me if I’m wrong—Cerwin-Vega is pretty much the only brand left selling big, beefy consumer speakers at prices the masses can afford.
(I’m excluding small, niche speaker manufacturers from this assessment.)
Okay, that might be a topic for another thread.

https://cerwinvega.com/collections/hi-fi-speakers-and-subs?srsltid=AfmBOooEzpicHuJsdFShjl839t79W-LvVrMZx9WMGqP0SNiQ5-RasNOg

 

[Penelinfi]

Some people seem to want a regular tower speaker design, with a "normal" wg dome tweeter . .

 

[MZKM]

Reserved