KEF R Series with MAT white paper

[McFly]

No other manufacturers come close (iirc) to providing this level of data. Bravo

 

[exm]

Looks like R8 Meta frequency graph is missing, will that be added?

 

[fineMen]

No other manufacturers come close (iirc) to providing this level of data. Bravo

They are so good, we better find something to argue about.

The grille alters the frequency response severely with three (cavity) resonances / reflections. Why?

The shadow ring around the mit/treble unit seems to snap loose during transport regularly. People have a hard time to readjust it, as it takes lot of force which, slipping, destroys the speaker. A misaligned ring might cause up do 4dB of an alteration to the intended resposne. What is it about?

 

[NTK]

No other manufacturers come close (iirc) to providing this level of data. Bravo

Ascend Acoustics is providing full Klippel NFS Spinorama measurements. For example (measurements are in the measurement tab):

SIERRA-2EX V2 PAIR

Our New Benchmark Bookshelf Ribbon Speaker New Klippel NFS optimized version! Using high resolution 360-degree measurements generated by our Klippel NFS, we developed a new method of integrating our Sierra-2 RAAL ribbon with our EX woofer, greatly improving directivity and providing a more...

ascendacoustics.com

 

[JAJDACT]

Ascend Acoustics is providing full Klippel NFS Spinorama measurements. For example (measurements are in the measurement tab):

SIERRA-2EX V2 PAIR

Our New Benchmark Bookshelf Ribbon Speaker New Klippel NFS optimized version! Using high resolution 360-degree measurements generated by our Klippel NFS, we developed a new method of integrating our Sierra-2 RAAL ribbon with our EX woofer, greatly improving directivity and providing a more...

ascendacoustics.com

Yeah but for whatever reason (aesthetics,design maybe?) people aren't enamored with their speakers like they are with KEF's. When the Sierra LX was released people on here where asking for Amir to confirm Ascend's own Klippel data,like they weren't trustworthy. So far it seems like everyone is fawning over KEF's white pages.

 

[sarumbear]

Yeah but for whatever reason (aesthetics,design maybe?) people aren't enamored with their speakers like they are with KEF's. When the Sierra LX was released people on here where asking for Amir to confirm Ascend's own Klippel data,like they weren't trustworthy. So far it seems like everyone is fawning over KEF's white pages.

Maybe because KEF designs and manufactures all their drivers (and had been doing since inception) instead of buying from SEAS.

 

[Mario Sanchez]

It's all nice and dandy, and I love how the R6 Meta somehow doing away with the 7-8KHz DI dip present on the R3,5 and 7. There's just one gripe: can we have a rubber mallet packed into the box to deal with the shadow flare? My unit arrived with the ring about a milimeter out. It'd be lovely to have a mallet with the KEF logo on it as well...

 

[muad]

They are so good, we better find something to argue about.

The grille alters the frequency response severely with three (cavity) resonances / reflections. Why?

The shadow ring around the mit/treble unit seems to snap loose during transport regularly. People have a hard time to readjust it, as it takes lot of force which, slipping, destroys the speaker. A misaligned ring might cause up do 4dB of an alteration to the intended resposne. What is it about?

Interesting, I'm flip flopping between the R3 and the arendal 1961 towers, and I need to use them with grills on... Something something terrible toddlers.

Do you have any source of measurement showing the grill effects?

 

[fineMen]

Interesting, I'm flip flopping between the R3 and the arendal 1961 towers, and I need to use them with grills on... Something something terrible toddlers.

Do you have any source of measurement showing the grill effects?

Oh, sure!
green with grille
red w/o grille

Same e/q for best performance w/ grille attached. It looks so cute ... as always, watch the scaling!

 

[phoenixdogfan]

Hi folks, I'd like to share with you the white paper for the new KEF R Series with MAT (the newly released Meta models).

Big apologies for the delay we've had in publishing it, as I know some of you have been awaiting it since the market launch of the series. We've been a bit busy in R&D but I've made sure to include lots of interesting data and figures.

We've tried to go into as much detail as possible on the new technology in this iteration as well as adding new explanations on existing technology, so that you can have a global view of what we've achieved.

I sincerely hope you'll find it an interesting read and enjoy flicking through the pages.

I really do appreciate this. I own 4 LS 50's (2 Meta. 2 OG) and an HTC 3001 SE for my center, so I'm a big KEF fan. Look forward to seeing the new R series speakers being reviewed by either Amir and/or Erin in the near future. I'm sure the results will be stellar.

 

[phoenixdogfan]

Yeah but for whatever reason (aesthetics,design maybe?) people aren't enamored with their speakers like they are with KEF's. When the Sierra LX was released people on here where asking for Amir to confirm Ascend's own Klippel data,like they weren't trustworthy. So far it seems like everyone is fawning over KEF's white pages.

All Dave has to do is send a pair of Sierra LX's to Amir to confirm his own Klippel 2034. I, for one, would very much like to see the result of those measurements, and since the speaker is already a year old, I wonder what the hold up is. Would also like to see the GGNTKT M1's as well.

If these designers want to get full exposure for those designs, they need to get off the dime, and submit them for review and independent measurement.

 

[abdo123]

All Dave has to do is send a pair of Sierra LX's to Amir to confirm his own Klippel 2034.

I would do it for the exposure alone. the measurements will be the same anyway because it's a robot. we've seen this already many times.

 

[sarumbear]

I sincerely hope you'll find it an interesting read and enjoy flicking through the pages.

Many thanks for this. I have 3x Ci5160REFM-THX (LCR) plus 10x Ci3160RL-THX on my 7.2.7 system. I know Ci5 has Meta absorbers but what about Ci3?

 

[muad]

All Dave has to do is send a pair of Sierra LX's to Amir to confirm his own Klippel 2034. I, for one, would very much like to see the result of those measurements, and since the speaker is already a year old, I wonder what the hold up is. Would also like to see the GGNTKT M1's as well.

If these designers want to get full exposure for those designs, they need to get off the dime, and submit them for review and independent measurement.

I tried sending my LX to amir/Erin but ascend wouldn't let me send it directly to them. They said something about having to send it to the purchaser and that they knew I was sending it for review lol. Either way, I didn't like the tonal balance, too much upper mids for me. But the bass... Incredible.

Oh, sure!
green with grille
red w/o grille

Same e/q for best performance w/ grille attached. It looks so cute ... as always, watch the scaling!
View attachment 280267

Awesome thanks! I wonder about the audibility if the grill. How will it measure over the total listening area and affect the MLP response.K EFs have a great vertical polar, and love how I can walk around the living space with the sound barely changing.

 

[fineMen]

Awesome thanks! I wonder about the audibility if the grill. How will it measure over the total listening area and affect the MLP response.K EFs have a great vertical polar, and love how I can walk around the living space with the sound barely changing.

Good that you ask. The 7kHz dip is restricted to a quite narrow angle around 'on axis'. As usual the interference changes style with angle, filling in the 7k, opening up much lesser dips 'n peaks elsewhere in frequency like +/-3dB or so.

 

[muad]

Good that you ask. The 7kHz dip is restricted to a quite narrow angle around 'on axis'. As usual the interference changes style with angle, filling in the 7k, opening up much lesser dips 'n peaks elsewhere in frequency like +/-3dB or so.

So the EIR should remain relatively close to what it would be now?

It would be interesting to see a Klippel with and without the grill. I haven't seen that measurement performed on any speaker (,except the Linton, where it was designed to be used with the grill, but that's a special case where the grill acts like a waveguide.

 

[davidbosch]

Now that’s PERFECTION.

I was more focused on the polar patterns because you guys aimed at a flat response everywhere anyway.

Is there a reason why high frequencies are struggling (lobes) a bit in other models in the vertical radiation?

Hi @abdo123 , thanks for your question, you have an eagle eye. The dips that you can see at high frequency on the vertical directivity of the floorstanders and R3 either side of the listening window are actually artefacts from the interpolation method I'm using to generate the data in between vertical measurement angles for these graphs. This interpolated data doesn't make it into the Spinorama calculation though. In the R6 and R2 horizontal directivities you don't see this because the measurement resolution is much higher, even though the driver arrays are very similar to R7 and R5 (without the bottom baffle portion) respectively. There's some room for improvement in how we present this in the future.

 

[davidbosch]

Looks like R8 Meta frequency graph is missing, will that be added?

Hi @exm , I know, it looks a bit odd to see the empty page, we pondered this, but R8 Meta is a bit of an outlier in that it has primarily been designed to comply with the Dolby Atmos guideline, so mainly a strict directivity window, which is narrower, and the grille is part of what makes this possible. So it's hard to see if it makes sense to evaluate it by showing its Spinorama, where for normal stereo forward-facing speakers we'd be chasing a wide and smooth directivity and power response.

PS. I like your profile icon, when are you upgrading it to the Reference Meta Uni-Q?

 

[fineMen]

So the EIR should remain relatively close to what it would be now?

It would be interesting to see a Klippel with and without the grill. I haven't seen that measurement performed on any speaker (,except the Linton, where it was designed to be used with the grill, but that's a special case where the grill acts like a waveguide.

I like the grilles for the looks, because they remind me of 1950s something speaker aesthetics, especially when the R3 is seated on its sidewall. The dips in response don't bother me so much. To my tin ears the anyway excellent clearity and articulation is maintained.

 

[davidbosch]

They are so good, we better find something to argue about.

The grille alters the frequency response severely with three (cavity) resonances / reflections. Why?

The shadow ring around the mit/treble unit seems to snap loose during transport regularly. People have a hard time to readjust it, as it takes lot of force which, slipping, destroys the speaker. A misaligned ring might cause up do 4dB of an alteration to the intended resposne. What is it about?

Hi, that's right, some folk have encountered this issue after transportation under high temperature. Provided the rubber bungs holding the shadow flare ring are not damaged/warped by trying to push it in when the pegs are disengaged, the ring can slide back in and stay in place. The dip in the response around 1.2 kHz (reported on ASR somewhere) happens when the trim ring protrudes more than the gasket can seal and the cavity behind it is exposed. We changed this gasket in Meta and added a second gasket on the perimeter of the shadow flare trim ring to make the seal more robust.