KEF Blade Meta One

14 hours ago, steve59 said:

I think that KEF attempts to add nothing to the process is the reason so many find them dull. When I bought my R105/3's my buddies gave me grief because they all owned Klipsch and loved the boom and tizz. Personally I couldn't care what somebody spends their own money on, and I appreciate being afforded the same courtesy.

Sorry, I don't understand your post.

16 minutes ago, semente said:

 

Sorry, I don't understand your post.

None of it or anything specific?

3 hours ago, Confused said:

I recall experimenting with the positioning of my Blades. (Original Blade) Measuring with REW it was clear that I had a modest "null" at about 120Hz. Moving the speakers nearer to the front wall seemed to have little influence on the overall frequency response, but it did fill this null a little.

 

So I thought to myself, OK - as an experiment, why not try going right back to the 225mm minimum specified by KEF? Yes, it did help with the null, according to the measurements at least, but some things started to sound a little odd, this I could not live with. It was not long before the speakers were moved much further into the room. So 225mm / 9" did not work for me in my room, what was interesting though is that I could move the Blades only a little further into the room, the "odd sound" disappeared and things started to sound pretty decent again. Obviously this is all very room dependant, but I think for some you could get reasonable results much closer to the front wall than you might expect.

Are you using EQ?

I have the back of my Reference 3s some 200mm from the wall and added a low-shelf compensation filter. That way I have managed to avoid a broadish cancellation dip centred at around 125 Hz.

This diagram by Neumann indicates that the worst position for the woofer is distanced between 0.80m and 2.00m (bottom left table) from the front wall (it also shows the advantage of using subwoofers in minimising SBIR effects):

2 minutes ago, steve59 said:

None of it or anything specific?

I understand the part about your friends preferring Klipschs but not the first sentence.

Just about every review I've read of kef products, especially the Raymond Cooke days reading 'while KEF speaker xxx measures excellent I find them a bit dull and uninvolving'.  When I bought mine friends would mock me for not buying klipsch like they have. My conclusion was simply you earn your money you get to do whatever you want with it.  The boom and tizz was what I came away thinking about my demo of a pair of Lascala's.

I've just come back from the UK Hi-Fi Show Live at Ascot. I learned a lot!

Klipsch and Blades were on my speaker short list.

I was thinking horns because I have my Linn Klimax Twins nicely set up for vertical bi-amp my Snell Type A III, but the Twins struggle with the 12" Snell woofers. I thought high-sensitivity speakers might solve the problem (i.e. the hassle and disruption of having to trade-up power amps since I want to optimise funds for turntable and speakers).

I heard the Klipsch Cornwalls. Wasn't impressed. "Dull" is a word I would not not use! I saw the rest of the Klipsch range on "static display" i.e. not hooked up. I was underwhelmed by build quality. They looked like cheap furniture.

In the KEF room the Blades were out but not hooked up. They looked elegant and smart. I wasn't taken with the upmarket KEFs playing - can't recall model (plenty of folks sat listening tho'). I still need to hear the Blades. Probably they weren't hooked up because new models tend to get touted at Shows. Blades present similar amp power problem. Linn Solos would work (more W), but Twins won't cut it.

[Incidentally Tannoy sounded rubbish. That only leaves JBL for horns. I heard the baby brother of 4367 - and thought not better than my Snells. The speaker that impressed me most was Wilson Watt Puppy - stand out experience. Unlikely I'll stretch myself to those because of the amp implications. Would they work with Kaluga or other Class D? I might end up with ATC Active at this rate.]

I thought big Klipsch would come across aesthetically as grand. They didn't to me.

fwiw. Just Show chat.

2 hours ago, Iving said:

I've just come back from the UK Hi-Fi Show Live at Ascot. I learned a lot!

Klipsch and Blades were on my speaker short list.

I was thinking horns because I have my Linn Klimax Twins nicely set up for vertical bi-amp my Snell Type A III, but the Twins struggle with the 12" Snell woofers. I thought high-sensitivity speakers might solve the problem (i.e. the hassle and disruption of having to trade-up power amps since I want to optimise funds for turntable and speakers).

I heard the Klipsch Cornwalls. Wasn't impressed. "Dull" is a word I would not not use! I saw the rest of the Klipsch range on "static display" i.e. not hooked up. I was underwhelmed by build quality. They looked like cheap furniture.

In the KEF room the Blades were out but not hooked up. They looked elegant and smart. I wasn't taken with the upmarket KEFs playing - can't recall model (plenty of folks sat listening tho'). I still need to hear the Blades. Probably they weren't hooked up because new models tend to get touted at Shows. Blades present similar amp power problem. Linn Solos would work (more W), but Twins won't cut it.

[Incidentally Tannoy sounded rubbish. That only leaves JBL for horns. I heard the baby brother of 4367 - and thought not better than my Snells. The speaker that impressed me most was Wilson Watt Puppy - stand out experience. Unlikely I'll stretch myself to those because of the amp implications. Would they work with Kaluga or other Class D? I might end up with ATC Active at this rate.]

I thought big Klipsch would come across aesthetically as grand. They didn't to me.

fwiw. Just Show chat.

You can't really assess sound quality at hi-fi shows.

The best thing to do is to choose a couple of dealers who stock speakers from your shortlist and arrange a few demos, preferably at home if possible.

3 hours ago, semente said:

This diagram by Neumann indicates that the worst position for the woofer is distanced between 0.80m and 2.00m (bottom left table) from the front wall (it also shows the advantage of using subwoofers in minimising SBIR effects):

This diagram predicts results from a speaker which emits sound only from its front surface.  This is not the case for the Blades which emit bass from the sides as well as the rear-directed ports.  

8 minutes ago, Kal Rubinson said:

This diagram predicts results from a speaker which emits sound only from its front surface.  This is not the case for the Blades which emit bass from the sides as well as the rear-directed ports.  

Below 80Hz the speaker acts roughly as an omni sound source, that includes ports and side woofers.

Above 80Hz the port output has dropped significantly (and they can be plugged).

You do have the back-to-back woofers operating as omnis for most of their operating range, which goes up to 300Hz.

I think that the principle still applies but happy to be corrected.

https://www.stereophile.com/content/kef-blade-two-meta-loudspeaker-measurements

9 minutes ago, Kal Rubinson said:

This diagram predicts results from a speaker which emits sound only from its front surface.  This is not the case for the Blades which emit bass from the sides as well as the rear-directed ports.  

Maybe you can ask Jack Oclee-Brown at A S R.

2 minutes ago, semente said:

 

Below 80Hz the speaker acts as an omni, that includes ports and side woofers.

Above 80Hz the ports are no longer operating.

You do have the back-to-back woofers operating as omnis for most of their operating range, which goes up to 300Hz.

I think that the principle still applies but happy to be corrected.

Agreed.  The ports are down about 10dB at 80Hz but not completely out and the side-mounted woofers are crossed over at about 400Hz.

9 hours ago, Kal Rubinson said:

This diagram predicts results from a speaker which emits sound only from its front surface.  This is not the case for the Blades which emit bass from the sides as well as the rear-directed ports.  

As wavelengths are pretty long below 400Hz and the speaker is rather slim, you can expect everything in the bass and lower midrange to be more or less omnidirectional so it does not really matter much where the exact source is located.

9 hours ago, semente said:

Below 80Hz the speaker acts roughly as an omni sound source, that includes ports and side woofers.

Would rather say, below 400Hz we have something close to an omnidirectional source if you look at the 4pi energy. Moving up in frequency, still at 1K directivity has narrowed only a bit which is seemingly a sideeffect of high x-over frequency, moderate filter slopes, side-mounted woofers and comparably tiny midrange in a non-existent baffle (that's the whole concept of Blade). I was rather surprised seeing the side woofers going up to 600Hz before reaching the -10dB point which is a thing most loudspeaker designers would avoid under any condition.

So we can expect significant amount of indirect sound in the room below 1K while above 1K the off-axis energy is dropping rapidly the higher you go. This does not mean it will be sounding like that in every room, but it is safe to say the performance is very much depending on room and positioning, much more than with other speakers.

3 hours ago, Arindal said:

 

As wavelengths are pretty long below 400Hz and the speaker is rather slim, you can expect everything in the bass and lower midrange to be more or less omnidirectional so it does not really matter much where the exact source is located.

 

 

Would rather say, below 400Hz we have something close to an omnidirectional source if you look at the 4pi energy. Moving up in frequency, still at 1K directivity has narrowed only a bit which is seemingly a sideeffect of high x-over frequency, moderate filter slopes, side-mounted woofers and comparably tiny midrange in a non-existent baffle (that's the whole concept of Blade). I was rather surprised seeing the side woofers going up to 600Hz before reaching the -10dB point which is a thing most loudspeaker designers would avoid under any condition.

 

So we can expect significant amount of indirect sound in the room below 1K while above 1K the off-axis energy is dropping rapidly the higher you go. This does not mean it will be sounding like that in every room, but it is safe to say the performance is very much depending on room and positioning, much more than with other speakers.

 

 

The change in directivity knee seems to be at around 200Hz

45°,60°&75°

https://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=1540:nrc-measurements-kef-blade-two-loudspeakers&catid=77:loudspeaker-measurements&Itemid=153

3 hours ago, Arindal said:

I was rather surprised seeing the side woofers going up to 600Hz before reaching the -10dB point which is a thing most loudspeaker designers would avoid under any condition.

 

So we can expect significant amount of indirect sound in the room below 1K

There’s a cancellation dip to the sides of the speaker centred around 450Hz so that significant amount is unlikely.

It’s certainly not visible in JA’s in-room response plot posted earlier.

43 minutes ago, semente said:

The change in directivity knee seems to be at around 200Hz

This is the frequency band in which directional effects of the woofers´ size and positioning (there are 4 of them) would come into play, but this is not contradicting the fact that overall it is pretty close to omnidirectional below 400Hz. 

The graph is showing another interesting thing which corresponds with the impression of ´dull´, midrange-heavy reflections and reverb: There is little to no directional effect in the midrange between 600 (this is where the woofers are sufficiently attenuated so midrange is dominating) and 1,500Hz with off-axis level dropping significantly between 1,500 and 4,000Hz (due to directional effects of the midrange plus waveguides). Note that we are talking about frequency response under 60 and 75deg which is corresponding pretty accurately with the tonal balance of the side wall reflections and having a significant influence on how the indirect sound field is perceived.

That is a very good explanation for the fact that these speakers sound very differently in different rooms, particularly depending on reflexiveness of and distance to the sidewalls, absorption in the midrange region as well as listening distance. 

41 minutes ago, semente said:

There’s a cancellation dip to the sides of the speaker centred around 450Hz so that significant amount is unlikely.

That is to be expected as the wavelength is equalling 75cm in this case making it pretty likely that dips around 450Hz are the result of a cancellation from the woofer duo of the other side of the loudspeaker and the added distance as well as cancellation between midrange and woofers.

Both phenomena are a reason why I mentioned loudspeaker designers would usually avoid such constellation (or choose a much lower x-over frequency). On the other hand such cancellation effects usually affect only a very narrow range both frequency- and angle-wise so they do not really help for significant directivity index and would not be visible in any in-room measurement.

19 hours ago, semente said:

Are you using EQ?

Currently, I am using convolution filters created using Focus Fidelity Filter designer.

Although for clarity, at the time I performed the "9 inches from the wall" experiment, as mentioned in an earlier post, I was not using any kind of EQ or room correction.