Radiant Acoustics Clarity 66 Speaker Review

[DanielT]

Nope

What exactly do you mean by “relatively high distortion”? Are you referring to distortion that is actually audible? And if so, at what listening level?

I can say that I have owned and listened to many very good speakers, both hi-fi and studio monitors, including some that are not particularly expensive. For example, the Elac Debut Reference DBR-62, which I recently listened, showed no audible distortion at normal listening levels in a typical living room, despite not necessarily having the very best measurements compared to some newer designs using state of thé rat woofers

Of course, having a speaker like the Radiant Acoustics Clarity 66 with even lower measured distortion is the icing on the cake, and it is certainly nice to have. Better measurements can bring benefits, especially at higher SPLs or in more demanding situations but rarely in daily use as some of us do, listening after work, decompress and enjoy good sound at home on a good set up


But at the end of the day, if the distortion is below the threshold of audibility in real-world listening conditions, then it is simply not something we hear. Measurements are important, but ultimately we listen to music, not graphs.

The asking 10k dollars surf on the selected woofers .. high expectations and you get what is gives : very very low distorsion. But low distorsion is already very low

I would have like to see the a fequency response slighly more linear , but i'm picky here

The ability to perceive or detect distortion is, to a large extent, a matter of practice. To practice and gradually improve, you need equipment with progressively lower levels of distortion. All I meant to say is that once you’ve gotten used to really low distortion, going back to the old way might feel a bit dull. I’ll leave aside the question of where the theoretical minimum audible distortion level lies—regardless of one's ability to detect it.

By the way, I’m not some extreme distortion-sniffing king capable of hearing the slightest trace of distortion; it was just an observation based on principle.

Edit:
Quote from another thread,#66:


Anyone who has embraced the use of truly low-distortion speakers knows what this means - going from around 0.3-0.5% THD in the midrange and treble to around 0.05-0.1% THD clearly reduces a grittiness that you don't always be aware of before the switch. A warning should be issued here, as there is no going back after hearing what it should sound like.

It is also interesting that deliberately rather "dirty" popular music recordings also sound cleaner, or perhaps rather more distinct, even though the raw sound even increases, i.e. that the listener hears exactly the distortion that was intended. The difference can sometimes be strikingly large even here, which probably surprises many
_________
Technical consultant in acoustics and audio technology

A Broad Discussion of Speakers with Major Audio Luminaries

I’m curious about what, if anything at all, frequency response leaves out in telling us how loudspeaker will sound. As I understand you’ve written that most things that matter will show up in the frequency response - including driver or cabinet colorations due to resonances (please correct me...

www.audiosciencereview.com

 

[henz]

I’m not a fan of subs, so I would definitely pick the larger speaker. I don’t claim I’m typical or representative of any trend, but four subs is certainly not domestically acceptable! However, in a dedicated room you can try whatever you like.

Having sold hi-fi in a shop for +7 years prior to me joining Nordic Hi-Fi, I can tell you that shockingly few customers consider or even want subs. At least in Scandinavia!

 

[dfuller]

Nope

What exactly do you mean by “relatively high distortion”? Are you referring to distortion that is actually audible? And if so, at what listening level?

I can say that I have owned and listened to many very good speakers, both hi-fi and studio monitors, including some that are not particularly expensive. For example, the Elac Debut Reference DBR-62, which I recently listened, showed no audible distortion at normal listening levels in a typical living room, despite not necessarily having the very best measurements compared to some newer designs using state of thé rat woofers

Of course, having a speaker like the Radiant Acoustics Clarity 66 with even lower measured distortion is the icing on the cake, and it is certainly nice to have. Better measurements can bring benefits, especially at higher SPLs or in more demanding situations but rarely in daily use as some of us do, listening after work, decompress and enjoy good sound at home on a good set up


But at the end of the day, if the distortion is below the threshold of audibility in real-world listening conditions, then it is simply not something we hear. Measurements are important, but ultimately we listen to music, not graphs.

The asking 10k dollars surf on the selected woofers .. high expectations and you get what is gives : very very low distorsion. But low distorsion is already very low

I would have like to see the a fequency response slighly more linear , but i'm picky here

I personally am a big fan of extremely low distortion - things sound "more real" that way. I would also keep in mind that Amir's distortion measurements are not true anechoic and actually are a bit higher than others in the LF region.

I would say this is a little better wrt distortion than the free-field measurements I've seen of other midfields, but it's a lot better than any 2x6.5" towers. That's where Purifi seems to have really managed something incredible, this is matching or beating 10" woofer class speakers.

Consider the KH420, from Neumann's measurements:

We can see that at 95dB free-field it's hanging on juuuuust below 3% down to about 30hz or a bit lower. And this is really good performance. But it's a big speaker with a 10" class woofer.

The Clarity 66 beats this out pretty handily, not reaching 3% at all until about 35hz and considerably lower above that. That's what makes Purifi special, IMO.

 

[Lars Risbo]

Even stays below 3% down to 30Hz at 101dB according to my measurements. There is a video review with blinded comparison of the 66 vs 6.2 plus subs. the subs win on raw SPL but the 66 solo was preferred for sound quality in the bass.

 

[Coltr@ne]

The problem is solved elegantly by a simple passive LCR circuit. But yes, theoretically it might be solved as well by a digital amplifier with very sophisticated current and voltage feedback circuitry.

It's not really a practical solution. I mean, Purifi is recommending this as the best solution. You know, Bruno Putzeys...he didn't step in to advocate for a digital amp with sophisticated programmable current and voltage feedback circuitry to develop a frequency dependent high impedance on the output terminals.

So I concede your point but will still just solve the problem equally and more cheaply with an LCR trap.

I suppose there's nothing stopping you from putting the LCR network in a multi-amplified speaker as well. Or not

 

[markk]

I suppose there's nothing stopping you from putting the LCR network in a multi-amplified speaker as well. Or not

No this is absolutely fine, the hybrid approach. No reason you can't go dsp-->amp-->passive series LCR-->drive unit. As long as the driver looks back and sees a higher impedance first in the form of that passive network, doesn't matter what's driving it upstream of that.


Even if you're building an active system, you might still want to look at the drivers FR curve and use a passive LCR in series with the driver to minimize the distortion component as necessary if you have a significant resonance within a couple octaves of the passband.

 

[Marc v E]

Even stays below 3% down to 30Hz at 101dB according to my measurements. There is a video review with blinded comparison of the 66 vs 6.2 plus subs. the subs win on raw SPL but the 66 solo was preferred for sound quality in the bass.

(Post corrected. Quoted someone else accidentaly)

Do you mean this one?

If so, yes I can hear a clarity in the 66 even through headphones. But, if I'm not mistaken I can hear that the standmounts sound kind of muffled due to close proximity to the sides of the passive radiator. It's mentioned by themselves too at 6:30, so I'm not the only one. Imo it sounds as if the subs and speakers integration could be better than what I hear there. Anyway, I will listen to them in person to hear what they can do.

 

[Nopiano]

Having sold hi-fi in a shop for +7 years prior to me joining Nordic Hi-Fi, I can tell you that shockingly few customers consider or even want subs. At least in Scandinavia!

My experience too, though my hifi retail days were 1973-1986 and only on Saturdays. It’s challenging enough to wire a stereo neatly, without subs scattered around!

 

[Nopiano]

I personally am a big fan of extremely low distortion - things sound "more real" that way.

It’s interesting that in amplifiers, Nelson Pass and Dan d’Agostino are two designers who deliberately permit some distortion to improve the subjective sound of their products. (Source: Hifi News reviews of their designs*)

*Illustrative quote from XA30.8 power amp review, lab report - “Versus frequency this same gentle increase in THD with increasing output is maintained [see Graph 2, below]. From 0.0029-0.009% at 100mW/8ohm to 0.058-1.26% at 50W/8ohm (all 20Hz-20kHz) this colour, favoured by many audiophiles, is seemingly a hallmark of Nelson Pass’s proven complementary, current feedback power amp topology.”

 

[amirm]

Visual bias aside, and I am not minimizing how important that is in our perception of sound, are you saying there is a relation on how big the sound is with how big the enclosure is.

For obvious reasons. The tweeter on Salon 2 is near 6 feet off the ground. The Genelec is good 2 to 3 feet lower than it so projects a smaller (vertical) image. You can to extremes and listen to 7 or 8 foot tall speakers as I have at shows. You have signers that now seem to be the size of monsters!

 

[amirm]

Not saying it is not so, I don’t know, but I find it surprising.

I should say that second hand, a Neumann 80DSP which I think projects a very small image, was found to be the opposite in blind tests a member performed a while back. So it may very well be influenced by the visuals.

 

[amirm]

How's this?

It is still wrong. The room was lit with warm lighting and was at night time, producing very different tonality than reality in proper lighting. Indeed I played around with Hue and Color Temp but could not come close to reality.

Basically speaker is different shades of black.

 

[amirm]

I can say that I have owned and listened to many very good speakers, both hi-fi and studio monitors, including some that are not particularly expensive. For example, the Elac Debut Reference DBR-62, which I recently listened, showed no audible distortion at normal listening levels in a typical living room, despite not necessarily having the very best measurements compared to some newer designs using state of thé rat woofers

Throw my sub-bass track at them and they will definitely sound distorted. Not so with Clarity 66. You have to use the right content to detect such things.

 

[dfuller]

Do you mean this one?

I mean the one measured in this thread. The floor stander.

It’s interesting that in amplifiers, Nelson Pass and Dan d’Agostino are two designers who deliberately permit some distortion to improve the subjective sound of their products. (Source: Hifi News reviews of their designs*)

*Illustrative quote from XA30.8 power amp review, lab report - “Versus frequency this same gentle increase in THD with increasing output is maintained [see Graph 2, below]. From 0.0029-0.009% at 100mW/8ohm to 0.058-1.26% at 50W/8ohm (all 20Hz-20kHz) this colour, favoured by many audiophiles, is seemingly a hallmark of Nelson Pass’s proven complementary, current feedback power amp topology.”

I found that review and read through it; the distortion behavior rising pretty much linearly with output until clipping is indicative of a low feedback, very rudimentary design. Generally speaking these will sound "louder" sooner because of how our brains interpret sound - which is to say, more harmonics = higher perceived loudness - and that might be the subjective reason for preference.

 

[Marc v E]

No, I mean the one measured in this thread. The floor stander.

Sorry, quoted you accidentaly. Corrected now.

 

[Gremlins]

Throw my sub-bass track at them and they will definitely sound distorted. Not so with Clarity 66. You have to use the right content to detect such things.

Agree , but at what listening levels? Because i do sometimes listen to heavy bass titles and in my listening levels in my living room, i canot detect distorsion, never. Neither did some buddies do.

Why not if some guys crank up volume to madness listening levels distorsion will be audible but in normal volume levels ( which i believe 99% of us do) , distorsion is not a subiect, regardless of good speaker we are listening to.
I do know a guy that will crank up volume to madness levels, but that only because he wants yo show he has 250w amps ... Pass that, average listening levels are around 75-85db ..

 

[Gremlins]

I personally am a big fan of extremely low distortion - things sound "more real" that way. I would also keep in mind that Amir's distortion measurements are not true anechoic and actually are a bit higher than others in the LF region.

I would say this is a little better wrt distortion than the free-field measurements I've seen of other midfields, but it's a lot better than any 2x6.5" towers. That's where Purifi seems to have really managed something incredible, this is matching or beating 10" woofer class speakers.

Consider the KH420, from Neumann's measurements:

View attachment 547733

We can see that at 95dB free-field it's hanging on juuuuust below 3% down to about 30hz or a bit lower. And this is really good performance. But it's a big speaker with a 10" class woofer.

The Clarity 66 beats this out pretty handily, not reaching 3% at all until about 35hz and considerably lower above that. That's what makes Purifi special, IMO.

95db... That's deth people levels of listening .. thats loud in a living room
And even though some would listen at these levels , mixed in music is inaudible

 

[bmc0]

sophisticated programmable current and voltage feedback circuitry

It doesn't need to be programmable if the amp is purpose-built. In the case of an active loudspeaker with integrated amps, an amp with mixed-mode feedback is likely to be the cheaper solution if production numbers are high. As you say, however, it isn't a particularly accessible or cost-effective option for the DIYer.

I suppose there's nothing stopping you from putting the LCR network in a multi-amplified speaker as well.

This is what I did for my main speakers. Passive networks to balance sensitivity (minimizes noise) and raise driving impedance where useful (minimizes distortion), and digital filters for the rest. More info here.

 

[Cogito]

Which other speaker is better, at the same price?

Just a few comparable speakers (Also cheaper):

Revel Performa F226Be ($8,470/Pair)
KEF R11 Meta ($7,000/pair)
Martin Logan Masterpiece Classic ESL9 ($7,500/Pair)
Sonus Faber Sonetto V G2 ($7,000/Pair)
MoFi Sourcepoint 10 ($8,000/Pair)
Monitor Audio Gold 500 6G ($8,300/Pair)
Magnepan MG-3.7i ($8,800/Pair)

All from well respected and established companies with international dealer support and that have been around long before Radiant Acoustic's inception (2022). Don't get me wrong, the Clarity 66 speakers are very nice, but IMHO don't demand the $10k asking price.

​

 

[amirm]

Agree , but at what listening levels?

At almost any level. Typical speaker will play the notes softly and distorted. Better speakers play them at modest level but still some distortion. Only the best can play them at reasonably loud levels.