D'Appolito Style Coaxial vs Single Woofer (R2C vs R3)

[Sancus]

A lower pref rating than the R3 is expected because the R2C is sealed and has much less bass, clearly designed to be used in a HT with a sub. But that doesn't excuse the other issues.

Maybe the brightness above 4K is because it's designed for 10-20° off-axis listening, but there is still a lot of unevenness between 500hz-3K that is not present in the R3, and what's up with that crazy dip at 2K? According to their specs, the crossover is 2.9K.

It's always surprising to me how inconsistent the Uni-Q's performance is from speaker to speaker. It seems like you'd be better off turning an R3 on its side to use as a center than buying this. It'd look a bit lopsided I suppose if you want to center the Uni-Q, but that's it.

P.S. It remains a huge shame that we aren't getting dedicated posts for Erin's reviews anymore :/

 

[Ata]

Wow. I am totally disappointed. But also very glad that I didn't get this speaker (which I was about to do many times). Center channel speakers with a concentric driver shouldn't be that hard. At least for a company like KEF with so much experience and so many resources.

I share this (slight) disappointment, and now find it hard to shell LS50 Meta pair kind of money for a single R2c unit.

Back to the drawing board for a matching centre channel in my HT setup, I cannot help but gravitate towards one of Q150/Q350/LS50 (Meta). For the moment, I make do with my Sony A9G TV built-in centre "channel", which is far from ideal but better than a phantom centre.

Having said this, I would not rule out an issue with the specific unit being measured -- that would be more likely than KEF botching the job of providing a shorter and horizontal R5 in a sealed enclosure, and providing misleading measurements to their customers.

 

[Ata]

A lower pref rating than the R3 is expected because the R2C is sealed and has much less bass, clearly designed to be used in a HT with a sub. But that doesn't excuse the other issues.

Maybe the brightness above 4K is because it's designed for 10-20° off-axis listening, but there is still a lot of unevenness between 500hz-3K that is not present in the R3, and what's up with that crazy dip at 2K? According to their specs, the crossover is 2.9K.

The issues are squarely in the UniQ driver FR territory, and it is the same UniQ driver as the higher rated R3 and also LS50Meta. The cabinet appears top notch based on weight and price, should be heavily braced and lined. There is no port to worry about. The X-over should be similar if not the same as R3/R5, the frequencies are identical.

So really, not much left as an excuse for the wobbly FR results measured. Hence, my suspicion that the speaker (or driver) may have a hidden production/transport issue (detached lining, loose bracing, or something).

It's always surprising to me how inconsistent the Uni-Q's performance is from speaker to speaker. It seems like you'd be better off turning an R3 on its side to use as a center than buying this. It'd look a bit lopsided I suppose if you want to center the Uni-Q, but that's it.

I thought they are fairly consistent, generation to generation?

P.S. It remains a huge shame that we aren't getting dedicated posts for Erin's reviews anymore :/

Can't agree more.

 

[HooStat]

P.S. It remains a huge shame that we aren't getting dedicated posts for Erin's reviews anymore :/

Is this the new normal? I really liked the collaboration between the websites, as well as with other reviewers like @joentell

 

[Sancus]

Is this the new normal? I really liked the collaboration between the websites, as well as with other reviewers like @joentell

Yep, cause of this thread. I don't think it affects other reviewers, except as far as they might be displeased with the situation as well.

So really, not much left as an excuse for the wobbly FR results measured. Hence, my suspicion that the speaker (or driver) may have a hidden production/transport issue (detached lining, loose bracing, or something).

It's possible, but if so, doesn't say very much for Kef QC, unless it happened in shipping, but honestly, internal shipping damage like that is pretty unusual if things are packed properly.

I thought they are fairly consistent, generation to generation?

Well I expected this one to be near-identical to the R3 and it isn't. We've seen uneven midrange before on the Q350, and the LS50 Meta has it to a lesser extent. But the R3 is dead flat in the midrange(on both Erin's and Amir's reviews). And the treble brightness is an issue on the R3 as well just much less so. It seems like midrange/treble issues crop up randomly on the Uni-Q, and I thought that the higher priced/quality R-series would be free of them compared to the lower end, but that doesn't seem to be the case, which is moderately concerning.

Granted none of these speakers are THAT expensive, and I may be spoiled by the perfect matches-every-other-speaker response you get from individually factory-EQed actives. I don't think it's the end of the world, just kinda expected a bit better.

 

[Beave]

The issues are squarely in the UniQ driver FR territory, and it is the same UniQ driver as the higher rated R3 and also LS50Meta.

Minor correction: the UniQ driver in the LS50/LS50Meta is not the same as that used in the R3/R5/R7/R11. Just look at the surround, for one.

 

[Ata]

Minor correction: the UniQ driver in the LS50/LS50Meta is not the same as that used in the R3/R5/R7/R11. Just look at the surround, for one.

You are correct. LS50 is definitely not the same driver, it is Uni-Q gen11.

LS50 Meta driver is SP1772 (?) and is 5.25", whereas the Rxx coax drivers are 5" SP1753 with bigger shadow flare.

 

[a|F]

This is a timely thread, as I was been pondering the use of an R2C to pair with my R3's but have never been a fan of horizontal center channels. I'll stick with R3's across the front and have an extra unit for sale, in walnut color.

https://www.audiosciencereview.com/forum/index.php?threads/kef-r3-walnut-single-speaker.25693/

 

[KMO]

The R2C measurements there seem to differ so much from KEF's own, that I can't help but wonder whether the unit was faulty. Other speakers like the R3 and LS50 have had repeatable third-party measurements far closer to their white paper results.

(I'm in part suggesting this because I received one faulty LS50 Meta - since replaced under warranty, but it showed it can happen).

 

[KMO]

You are correct. LS50 is definitely not the same driver, it is Uni-Q gen11.

LS50 Meta driver is SP1772 (?) and is 5.25", whereas the Rxx coax drivers are 5" SP1753 with bigger shadow flare.

Midbass Uni-Qs like the LS50 (Meta) and R8a get the Z-Flex surround to cope with the extra excursion of going below 400Hz. They're also 130mm rather than 125mm.

The Uni-Q keeps getting incremental improvements, so the "generations" at this point are pretty much arbitrary lines where they choose one improvement to mark a new "generation."

I've gone through the white papers - it's a bit tricky to align because the 2018 R series paper mainly compares with the 2011 R series, and the LS50 Meta paper compares to the LS50. But:

The 2018 R series seems to have added the following over the LS50 Uni-Q:

• Reworked magnet system for both drivers - T-shape poles to increase and make more uniform flux density, improving linearity through excursion range
• Tweeter gap damper - eliminate resonances in the gap between the tweeter waveguide and midrange coil (this change marks the 12th generation)
• Improved spider design? But not mentioned in either LS50 or LS50 Meta papers. May be specific to midrange Uni-Q?

The LS50 Meta picks up from the 2018 R series, and adds:

• Metamaterial absorption technology - eliminates 600Hz-5kHz reflections from rear of tweeter
• 2.5x area tweeter duct to work with MAT, also reducing distortion from air pressure
• Redesigned tweeter gap damper - same function, but new design needed for new duct and MAT
• Stiffened waveguide and support - reducing colouration from 5kHz-15kHz

Also, more aluminium rings were added in the midrange magnet system to further improve linearity, beyond the reshaping of the poles, but not clear whether that happened in R series or LS50 Meta. Overall magnet changes reduce THD in the 700Hz-2.5kHz range significantly between LS50 and LS50 Meta.

And they're still calling it "12th generation" but "with Metamaterial Absorption Technology".

 

[HooStat]

Yep, cause of this thread. I don't think it affects other reviewers, except as far as they might be displeased with the situation as well.

Thanks for pointing that out. It is a shame because the result is in nobody's best interest. I believe both of them have the best of intentions and if they can't collaborate, we all lose out.

 

[hardisj]

Which is Better for Home Theater: (3) Kef R3 or (3) Kef R2c Center Channel speakers?