Radiant Acoustics Clarity 66 Speaker Review

[Robbo99999]

I get that it's a really good speaker when it comes to distortion, but the directivity is not that great and it's really expensive, and then you've got the upwards tilt of the frequency response albeit you could fix that with some parametric linear tone control filters (63Hz Q0.5 / 632Hz Q0.5 / 6324Hz Q0.5). Yes, so I didn't give it the highest vote.

EDIT 28/7: ah, so the review has now been updated to make it clear the price is per pair, well that makes it better - I think I'd say they're still a bit expensive, but a lot more sensible now.

 

[Lars Risbo]

note that diffraction and directivity are two sides of the same coin

 

[Gremlins]

You're just not the market niche.

If said audiophile owns a 10k esoteric amp they really like, well, changing their mind is like trying to convince someone to change their political party.

I think a manufacturer over the long term probably would do well to target both markets as there is money to be made in both niches. As long as they can have better performance in their niche than the other manufacturer, they will do ok. There is still money to be made in this style of speaker if they can do it better than the competition.

Yes and no
I know some audiophiles going genelec or neuman and no more expensive hifi brands speakers or accuphase amps for example.

it take years to some going that path, and to some folks even more , to purchase clever in this hobby and it does happen that some subjective people finally become objective , thanks to this site for example

 

[amirm]

The general market for active speakers in hi-fi is indeed, quite a bit smaller. However, the market size portion among the people who care about this technology, i.e. us, , is a lot bigger. To wit, we can't get enough supply of Ascilab C8C to meet demand. Technical enthusiasts who would understand the value of Purifi driver and implementation of 66, would surely also value active design.

This speaker with active DSP and amplification can have perfect on-axis response and more refinement. And would then justify its cost. Keep the added cost to $1K to $2K and it would be a stronger offering.

 

[capslock]

66 and 6.2 share the same waveguide with the fins

Now that I've found a better picture of the 6.2, I can see it too. Do they share the same AMT driver, too? Any reason the 66 uses the aluminum cone and the 6.2 the paper cone? The aluminum cone has lower distortion, so maybe it is about the intended sound of the 6.2?

 

[capslock]

This isn't a BR. It's a MLTL - quarter-wave transmission line enclosure with a port.

Is it? The marketing materials seem to tell a different story. The description at Radiant makes it seem like it is a regular BR just with a special port optimized to lower turbulence. At Hifi Klubben which I believe is also owned by Lyngdorff both the description and the specs clearly state it is BR while also waxing about the custom port.

 

[Michael Kohler]

Maybe just maybe reliability and modularity (and not just performance alone) are still the concerns to people spending their money.

Yes. Perhaps that’s the case. But is the fear of active electronics failing justified? I can share my own experience from the last 25 years: three pairs of semi-active Martin Logan speakers, six active subwoofers from KEF and Martin Logan, and one pair of active speakers from Nubert—a German manufacturer. In that time, I experienced only one failure: the ICEpower amplifier module in one of the Martin Logans stopped working. That was the extent of it. So, is the fear justified?

 

[capslock]

This will make hard times, to some amplifiers. As well as the area near 60Hz (phase). EPDR would show it even more clearly.

View attachment 547498

Interesting. Seems to imply this is the impedance of the AMT once the high pass crossover is flat. But why use a low impedance AMT. Even an 8 R AMT would probably be too hot for these low efficiency woofers. Or if you spec a low impedance AMT, drive it with some series resistance to keep power compression low. Or is this the result of a rather low impedance tweeter pad?

 

[raindance]

WOOH! Idea picked up from Monitor Audio!

Vivid do it this way also.

 

[Wolfram98]

Well, for this price a Revel Salon2 was a clear contender, too bad it was discontinued.
Wonder how they fare against these 66.

 

[Lars Risbo]

Interesting. Seems to imply this is the impedance of the AMT once the high pass crossover is flat. But why use a low impedance AMT. Even an 8 R AMT would probably be too hot for these low efficiency woofers. Or if you spec a low impedance AMT, drive it with some series resistance to keep power compression low. Or is this the result of a rather low impedance tweeter pad?

The AMT has just barely enough sensitivity. The waveguide with coherer (aka the fins) spreads the energy which lowers the on axis sensitivity. We basically run the tweeter filter straight through at high frequencies. This is also reflected in the impedance drooping.

 

[Lars Risbo]

Is it? The marketing materials seem to tell a different story. The description at Radiant makes it seem like it is a regular BR just with a special port optimized to lower turbulence. At Hifi Klubben which I believe is also owned by Lyngdorff both the description and the specs clearly state it is BR while also waxing about the custom port.

A BR and TL box loading are just two points in a continuum of solutions. The 66 box is tall and slim and acts as a damped transmission line. I even think we mentioned this in one of the videos. the port is placed away from the woofers which helps remove midrange leakage (the line damps high frequencies). A nice side effect is that the box (aka line) becomes part of the port which can be made shorter for the same tubing frequency compared to a more cubic box. And yes, this is often called an MLTL. Again, it’s all just shades of grey where you trade off damping of higher order parasitic modes

 

[Universal Cereal Bus]

However, the market size portion among the people who care about this technology, i.e. us, , is a lot bigger.

This is the "Moneyball" effect spreading to various corners of society.

 

[eliash]

This will make hard times, to some amplifiers. As well as the area near 60Hz (phase). EPDR would show it even more clearly.

View attachment 547498

My T+A R-Series A1500 power amp would probably cope with that impedance (doubled high current emitter follower output stage + 300KHz power BW)

 

[JPA]

Not bad, but for $10k not good enough.

 

[Curvature]

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

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.

 

[markk]

A BR and TL box loading are just two points in a continuum of solutions. The 66 box is tall and slim and acts as a damped transmission line. I even think we mentioned this in one of the videos. the port is placed away from the woofers which helps remove midrange leakage (the line damps high frequencies). A nice side effect is that the box (aka line) becomes part of the port which can be made shorter for the same tubing frequency compared to a more cubic box. And yes, this is often called an MLTL. Again, it’s all just shades of grey where you trade off damping of higher order parasitic modes

When I hear "MLTL" I always think of something designed with Martin King's MLTL software. Yes, I know transmission line speakers and their theory have been around way, way before he started his site. I tend to think of MLTLs as a more unique solution to the general concept of BR that has clear advantages. I've built a few, heard a few, and found the bass in a box designed this way to be very respectable, better in general than the average ported system.

My. personal preference is for sealed, especially for active, but MLTL designs in a passive system, done right sound very good indeed.

 

[markk]

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.

10% =-20
1% = -40
0.1%=-60

There is a bit of conversion in the head, but it's pretty common to use percentages as well. You don't have to worry about -80 or -100 because, well, no one's speakers are that good. That's DAC and amp stuff!!!

 

[amirm]

Well, for this price a Revel Salon2 was a clear contender, too bad it was discontinued.
Wonder how they fare against these 66.

Revel Salon 2 list price was around $22K. The end of life sale got it down much lower but that was not its normal cost.

 

[amirm]

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.

Sure. Here is AI conversion: