Is the KEF brand slipping in quality recently?

[ridikas]

The title says it all. KEF has made some of my all time favorite speakers. Their Reference, Blade, and Muon speakers sound and measure incredible. They are some of the best speakers in the world, at any price.

But, companies like KEF, Revel, Dynaudio, Polk Audio, B&W, NHT, PSB, etc. should have wonderfully built, engineered, and performing speakers in the $1000-$2000 market.

KEF has two good lines of budget speakers, the new R series and the somewhat new Q series. Just as an example, the Q series is priced competitively with the Revel Concerta line and the R series is the equivalent to the Revel Performa series.

Here is the rather troubling recent KEF trend:

KEF Q900 - KEF Q900 loudspeaker Measurements | Stereophile.com
KEF Q900 and Q100 - KEF Q900 Speaker System HT Labs Measures | Home Theater
KEF R500 - NRC Measurements: KEF R500
KEF R300 - KEF R300 Speaker System HT Labs Measures | Home Theater

These are speaker lines that range from $550pr. - $5000pr.

Looking at the Q900 towers, one can see that KEF used a hard cone midrange/mid-woofer driver, with the typical cone break-up and all they did in the crossover was to use a first order electrical. Which virtually has zero effect in controlling the cone's breakup.

The SPL might be acceptable for an extremely budget speaker, but the distortion would be through the roof, once this region is excited.

All of a sudden, the archaic Revel Concerta line is on another league in performance.

Same goes for for the R series versus the Performa. The Performa line measures impeccably.

This is coming from a huge fan of KEF, please do a little bit more engineering

 

[AcuDefTechGuy]

The listening window on the R500 is +1dB, -2dB; distortion above 200Hz is about zero @ 90 and 95 dB; off-axis doesn't look too bad.

The Q900’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +2.25/–0.65 decibels from 200 hertz to 10 kilohertz.

What do you see wrong?

The R300’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +1.03/–3.07 decibels from 200 hertz to 10 kilohertz.

Not great, but not too bad.

Remember, measurement isn't everything. Must consider measurement error by humans. As long as they are not + 4dB/ -4dB or worse.

You think the Revel F12 is better than the Q900?

Personally, I would take the F12 over the Q900, but I don't think they are that much different in quality.

In the end, if they sound great, with FR about +/- 3dB, so what?

 

[ridikas]

Hi Acu, yeah the SPL and off-axis response is quite decent on even the lower end KEFs, but I think you might be over simplifying the measurements.

The break-up mode in the KEF Q900 at around 8000Hz is completely not suppressed by the crossover. It's even visible in the SPL graph. Once this region is excited by music, the distortion will literally be through the roof. It will sound harsh and unnatural, even though the overall SPL is fairly flat.

These sorts of things are usually missing from most tests and in this case it's a complete eye opener.

Now I'm not sure how the break-ups are dealt with in the R series, because we simply don't have enough test data. Soundstage measures THD. I wish they would use Kippel, or Zaph's style of distortion data.

But even so, the Soundstage clearly shows that the R500s are +/-3dB, which is not comparable to the similarly priced Revel Performa speakers.

I cannot completely write off the R series until more data is available.

I can state with certainty that the Q series should sound pretty horrendous, because of extremely high distortion in at least the upper midrange due to major uncontrolled cone break-up. The Revel F12s have no break-ups whatsoever and they have an SPL of +/-2dB, or so. With an extremely good off-axis response.

I've heard the F12s and the Q300s, but at different locations and with a big time difference apart. The F12s sounded great, but could not compare to the Performa line. I did not care for the Q300s.

I'm not here to bash KEF, they are one of my favorite speaker manufacturers in the world. I'm just disappointed in their new budget and midline products.

Polk Audio, NHT, Revel are all ahead of the game, at least as of this year.

 

[canelli]

The q300 is nice speaker, but the r100 is much better. The r300 is in another league.

I was going to try the lower to mid range Revel speakers until the regional rep said they were older and suggested going something else.

 

[ridikas]

Revel has a whole new line coming out in December 2012, the Performa3.

 

[AcuDefTechGuy]

Hi Acu, yeah the SPL and off-axis response is quite decent on even the lower end KEFs, but I think you might be over simplifying the measurements.

The break-up mode in the KEF Q900 at around 8000Hz is completely not suppressed by the crossover. It's even visible in the SPL graph. Once this region is excited by music, the distortion will literally be through the roof. It will sound harsh and unnatural, even though the overall SPL is fairly flat.

These sorts of things are usually missing from most tests and in this case it's a complete eye opener.

Now I'm not sure how the break-ups are dealt with in the R series, because we simply don't have enough test data. Soundstage measures THD. I wish they would use Kippel, or Zaph's style of distortion data.

But even so, the Soundstage clearly shows that the R500s are +/-3dB, which is not comparable to the similarly priced Revel Performa speakers.

I cannot completely write off the R series until more data is available.

I can state with certainty that the Q series should sound pretty horrendous, because of extremely high distortion in at least the upper midrange due to major uncontrolled cone break-up. The Revel F12s have no break-ups whatsoever and they have an SPL of +/-2dB, or so. With an extremely good off-axis response.

I've heard the F12s and the Q300s, but at different locations and with a big time difference apart. The F12s sounded great, but could not compare to the Performa line. I did not care for the Q300s.

I'm not here to bash KEF, they are one of my favorite speaker manufacturers in the world. I'm just disappointed in their new budget and midline products.

Polk Audio, NHT, Revel are all ahead of the game, at least as of this year.

Are measurements of Polk or NHT on Stereophile and NRC any better than KEF?

I mean Polk? Really?

I know the Absolute Zero measured better than any speaker in the world in Home Theater Magazine, but the Stereophile and NRC measurements of NHT were not as great.

 

[ridikas]

Well yeah, these Polks ($1500pr. retail) destroy the KEF Q and R series and measure significantly better in every respect: Polk LS<I>i</I>M703 loudspeaker Measurements | Stereophile.com

Plus the Polks use real wood veneers, thick MDF curved cabinets which are extensively braced, Vifa XT25 tweeters which have state of the art distortion performance and feature motors with copper covered pole caps, etc.

Polk is one of the biggest speaker manufacturers in the world. They own multiple anechoic chambers and feature world class acoustical engineering. I'm not sure why a lot of people dismiss them.

 

[AcuDefTechGuy]

Well yeah, these Polks ($1500pr. retail) destroy the KEF Q and R series and measure significantly better in every respect: Polk LS<I>i</I>M703 loudspeaker Measurements | Stereophile.com

Plus the Polks use real wood veneers, thick MDF curved cabinets which are extensively braced, Vifa XT25 tweeters which have state of the art distortion performance and feature motors with copper covered pole caps, etc.

Polk is one of the biggest speaker manufacturers in the world. They own multiple anechoic chambers and feature world class acoustical engineering. I'm not sure why a lot of people dismiss them.

Damn. I better eat my words about Polk.

Damn.

 

[ridikas]

Polk has done a very nice job recently. The entire LSiM700 series is very well engineered and executed: LSiM | Polk Audio®

I had a chance to listen to the towers and the bookshelfs and was genuinely surprised. I love how a true 3-way speaker sounds. There are not that many well engineered 3-way bookshelfs out there. The Polks retail for $1500pr., but ABT Electronics had them on sale for $960pr. This is just an insanely good deal.

Very non fatiguing, smooth sound, with great horizontal off-axis response. I haven't seen any distortion measurements, but from what I heard during the demo, they must compete with the big boys. Built like tanks as well.

They blow away any similarly priced Focal towers, which ABT also carries. They're also better than the Dynaudio DM and Excite series, the Revel Concerta, B&W CM, NHT Classic, and Paradigm Studio in my opinion.

I would be curious to directly compare these Polks with KEF R, PSB Synchrony, and the new Revel Performa3 line.

 

[djreef]

Damn. I better eat my words about Polk.

Damn.

I've been running LSi Polks in my HT rigs for years. I love the way they translate dialog.

DJ

 

[Audioholics]

Here's what we thought of the KEF R700 speakers:

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I don't think KEF is slipping, so much as expanding their range to include a wider presentation of products.