[ted_b]

Ahhh, thanks.  Good info.

[Rocket_Ronny]

Albireo:

Can you share how you are liking the Mini's over the Kef's, and vise versa?

Thanks,

Rocket_Ronny

[Albireo]

Albireo:

Can you share how you are liking the Mini's over the Kef's, and vise versa?

Thanks,

Rocket_Ronny

Apologies, I got the same question over PM right after your post and didn't realize they were from different people! I still have a long way to go before I can make any succinct conclusions regarding the KEF 201/2 vs the Minis, but suffice to say I feel lucky that I can keep both speakers. Right now I tend to make myself listen to the KEFs, whereas I find myself looking forward to listening to the Minis. Even that may be putting it too strongly though!

A few things jump out at me:

- The Minis -- like the NuForce S-9 prior to them and the S-1 desktop speakers -- just sound live. Naturally live, as opposed to having to imagine it. There is no other way to describe it. The immediacy of the music is -- just -- right -- there. It is addictive! This is not a comment on the frequency balance (which like the 201/2's is extremely neutral) but some combination of micro- and macro-dynamics, dispersion characteristics, and a complete ignorance that the sound is being produced by mechanical objects (see below comment on the KEFs' treble).

- The KEFs have superior (and more even) roll-off when listened far off-axis, but that is a double-edged sword: I can hear a better semblance of the on-axis SQ when sitting 90 degrees to the drivers, but that means the room then contributes more to the on-axis performance. In the 201/2's case, that means a bit of a treble lift (wow, duh!). On the flip side, the Minis will appear to have less (fake?) air if you're used to that sort of thing.

- The KEFs are the more transparent speaker by a hair -- although very hard to know whether this is a due to some slight frequency response difference -- but I simply can't shake the impression that I'm hearing a metal-dome tweeter. Kinda wish KEF had used something that moved the resonance a bit higher up (perhaps beryllium?). Nevertheless, the KEFs' treble is easily characterized as sweet, and as I mentioned I find the 201/2s the more detailed of the two. That's saying something, as those with SP Tech speakers will know!

- The Minis completely disappear as a sound source which is visually surprising considering how big the Minis are. Now, the 201/2s are pretty massive too (although the Minis seem to weigh twice as much!) but whereas the 201/2's center image moves with you as you move across the couch, the image on the Minis sticks better to the space between the speakers. It has to be said that the KEFs center image does move extremely linearly across the stage as you move to one side: I don't know which presentation is technically correct. In any case, the "sticky" center image can also be a mixed bag: when sitting directly across from one speaker the Mini's "center" image is geographically correct but somewhat less precise than the 201/2's. I think most people will be more impressed with the Mini's center image when listening off-axis, but careful listeners will likely have less nits to pick about the 201/2's "center" image since it maintains better image specificity and detail. In my case, because I don't use a center speaker (yet), when I sit on one side of the sofa it can be a bit bizarre to watch movies where voices are off to one side of the screen, so I side with the Minis on this one.

- The Minis have the deeper bass extension. I don't have my measurements handy, but it's quite clear. As far as I can tell the bass is equally tight (maybe even tighter in the Minis) so this directly contributes to an increased sense of "liveness".

Does that help? I could go on and on, but probably should listen and think a bit more before I shoot off something I might regret later!

[Rocket_Ronny]

Thanks Albireo for that detailed review.

It's nice to know that the Mini hangs with the best of them.

Rocket_Ronny

[mcullinan]

Nice write up! Very informative. Give us more when your ready.
Mike

btw I heard the full range KEFs, the Ref series and they sound awesome. My impression was that the tweeter sounded very natural. And the build quality was freaking unbelievable! I only spent about twenty minutes with them, but I was curious right away if the tweet would have a negative effect. From what Ive read you can adjust the high frequency on the back, yes?
Mike

[Double Ugly]

Great comments, Albireo.  Sounds like you're really getting a handle on the Minis.

In the 201/2's case, that means a bit of a treble lift (wow, duh!). On the flip side, the Minis will appear to have less (fake?) air if you're used to that sort of thing.

- The KEFs are the more transparent speaker by a hair -- although very hard to know whether this is a due to some slight frequency response difference -- but I simply can't shake the impression that I'm hearing a metal-dome tweeter. Kinda wish KEF had used something that moved the resonance a bit higher up (perhaps beryllium?). Nevertheless, the KEFs' treble is easily characterized as sweet, and as I mentioned I find the 201/2s the more detailed of the two. That's saying something, as those with SP Tech speakers will know!

The above got me to thinking ... "more transparent" & "more detailed" vs. "less (fake?) air"... and I wondered why.  A quick Google search turned up the following from the July '08 Stereophile:

"Fig.4 shows how these individual drive-unit responses sum in the farfield, averaged across a 30° horizontal window centered on the tweeter axis. The bass rolls off a little earlier than the port tuning frequency of 50Hz might suggest, and there is a slight boost in the top octave."


Could the "slight boost" explain it, at least in part?

Regardless, everything I've found make the KEFs out to be great speakers.  It's good to hear the Minis are keeping up with some of the best reviewed monitors currently available.

[ooheadsoo]

Interesting point, Jim.  A lift in the treble can easily be heard as "more" this and that.  This is not to say it is good or bad.  I have these $20 cheap single driver computer speakers at work that do an amazing Coltrane and Sonny Rollins, in a way that I can't get my SP Techs to do.

[mcullinan]

Double,
Is there a frequency graph on the Minis yet? Maybe we could do a comparison that way.
Mike

[Val]

It has to be said that the KEFs center image does move extremely linearly across the stage as you move to one side: I don't know which presentation is technically correct.

Then the Minis win easily. I believe the point of the stereophonic phantom image is to be reproduced between the speakers, detached from them and as lifelike as possible. Just imagine being at a live jazz session and moving to the corner of the bar.

Thanks for the insight.

[Double Ugly]

Double,
Is there a frequency graph on the Minis yet? Maybe we could do a comparison that way.
Mike

I haven't seen one.  The last graph I saw from SP Tech was of on my own speakers' response. 

Regardless, what I'd prefer to see is a *real* comparison wherein the same unbiased entity (Stereophile?) measured and posted the specifications for the Mini.  Same equipment, same unbiased testing personnel, same facility, etc., etc..  That's the only way we could know for sure.

Though I believe Bob is one of the most honest and forthright people I know, there will always be those who doubt a manufacturer's claims. 

[Albireo]

Nice write up! Very informative. Give us more when your ready.
Mike

btw I heard the full range KEFs, the Ref series and they sound awesome. My impression was that the tweeter sounded very natural. And the build quality was freaking unbelievable! I only spent about twenty minutes with them, but I was curious right away if the tweet would have a negative effect. From what Ive read you can adjust the high frequency on the back, yes?
Mike

The titanium tweeter on the KEF is easily the best of the type I've heard, but the berylliums take it that one step further. Something for the next iteration of the Reference series, hopefully! If it wasn't for the quicker treble roll-off in the Minis and subsequent impact on "air", I wouldn't hesitate to pronounce its silk-dome the superior transducer. As it is, both materials have their advantages and disadvantages.

Note that my listening room -- OK, OK, it's my living room and kitchen too! -- is a typical Boston brownstone's: high 9.5' ceilings for a relatively compact footprint (14.5' x 17'). It's a "good" room for an untreated space, but as I have spent most of my life living in much tighter and shorter quarters I had gotten used to a certain degree of reflected treble "air." In any event my new room scores in greater focus so I guess as an audiophile I can hardly complain, but one often likes what they are used to rather than what is more correct!

Going off memory again, I was astonished to see that my measurements confirmed exactly what JA reported in the Stereophile review of the KEF 201/2, namely that the tweeter switch changes the treble response by just fractions of a dB between maximum and minimum attenuation. Astonishingly though, even this is very audible. I don't know what's going on there, but KEF clearly knows speaker engineering! This is why I have some confidence in the accuracy of my measurements, and look forward to taking more soon.

Val: I'm still not sure which center image presentation is most correct from an engineering standpoint. Seems to me that a speaker with more limited treble dispersion will by default be able to keep the center image more stable as you move off-axis, but that isn't saying which way is more right or wrong! That is, with the KEFs you may give up a stable center image but you get more consistent frequency balance in other parts of the room. Conversely, while the limited dispersion in the Mini will cause the sound to seem like its passing through an open window when you move far off-axis, the center image remains more anchored.

By the way, I hope I haven't given the impression that the KEFs are somehow omni-directional when compared to the Minis! Both have tweeter waveguides -- the Minis to extend treble response and the KEFs to meld the tweeter's dispersion with that of its concentric midrange driver -- so even the KEF has stronger treble roll-off when compared to the competition. Together with the Revel Studio2/Salon2's tweeter waveguide (albeit a very shallow one) it is clear that top shops are catching on to what Bob already figured out ages ago!

[Albireo]

Double,
Is there a frequency graph on the Minis yet? Maybe we could do a comparison that way.
Mike

I actually did some REW curves once but need to dig them up. In any case I want to do a test with my TacT RCS 2.2XP as well as with my PC setup with a calibrated Earthworks M30 mic.

I seem to remember that the REW results showed the Minis having a broadly higher treble response by a nose, but the KEF peaked higher just past 10kHz. I also remember being quite surprised at how closely they measured. Seem to recall that the Minis were smoother in the treble, but the KEFs were flatter in the midrange and below. All this is contingent on doing a more rigorous test, but what is really needed is for the Mini to be tested by Stereophile, as Jim pointed out. Hopefully JA will still be around by the time SP Tech becomes broadly distributed!

[Wind Chaser]

Seems to me that a speaker with more limited treble dispersion will by default be able to keep the center image more stable as you move off-axis, but that isn't saying which way is more right or wrong!

I don't think so.... Having owned Acoustat's back in the early eighties, these speakers were no merely limited in treble dispersion, but extremely directional from top to bottom - and without a waveguide at that!  Yet they were known for being a "head in the vice" listening experience.  Any lateral movement of your head would cause the image to radically shift.  They were not the type of speaker that could fill a room with sound.  Having that degree of directionality, room interactions were kept to an absolute minimum.

[Albireo]

Seems to me that a speaker with more limited treble dispersion will by default be able to keep the center image more stable as you move off-axis, but that isn't saying which way is more right or wrong!

I don't think so.... Having owned Acoustat's back in the early eighties, these speakers were no merely limited in treble dispersion, but extremely directional from top to bottom - and without a waveguide at that!  Yet they were known for being a "head in the vice" listening experience.  Any lateral movement of your head would cause the image to radically shift.  They were not the type of speaker that could fill a room with sound.  Having that degree of directionality, room interactions were kept to an absolute minimum.

Perhaps my intuition only applies to point-source designs? I know what you are talking about, having owned a Maggie and listened extensively to Martin-Logans, but the dispersion patterns are completely different for those flat-panel speakers, fundamentally. Even the on-axis behavior is different!

[Wind Chaser]

Maggies aren't in the same class or category as electrostatics.  Also they have a much wider dispersion.

Extreme directionality, could it be something fundamental to electrostatic speakers?  Perhaps, after all when the Quad ESL 63 debuted it's claim to fame was it had a wide dispersion.  But on the few occasions I heard them I wasn't impressed.  Was it because the wider dispersion led to room interaction?

It seems marketing campaigns along with the critics of the time duped people into thinking the wider the dispersion the better.  Now we know that ain't true.

[miklorsmith]

VMPS still holds true to the "wide dispersion" ideal.

[Albireo]

Maggies aren't in the same class or category as electrostatics.  Also they have a much wider dispersion.

Extreme directionality, could it be something fundamental to electrostatic speakers?  Perhaps, after all when the Quad ESL 63 debuted it's claim to fame was it had a wide dispersion.  But on the few occasions I heard them I wasn't impressed.  Was it because the wider dispersion led to room interaction?

I think extreme directionality may be fundamental to (true) flat-panel speakers in general? The Quads are different because they are fundamentally a point-source design. Also, the Maggies have wider dispersion because the QR tweeter approaches line-source behavior, and of course the ribbons are line-sources to begin with. But I remember the midrange and below on my MG1.6 -- flat-panel in that range -- rolled off much faster than the QR tweeter, leaving the off-axis behavior brighter (too bright). Perhaps because of the tweeter's greater dispersion though, the MG1.6 had a pretty solid off-axis center image in my room, though I do remember it smeared more than the Mini's. Some people get really poor center images with their Maggies though. And Martin Logans, despite the curved panels, are a joke off-axis.

It seems marketing campaigns along with the critics of the time duped people into thinking the wider the dispersion the better.  Now we know that ain't true.

Amen to that!

[Albireo]

VMPS still holds true to the "wide dispersion" ideal.

So does Gallo with their CDT drivers. But you know, I can't remember what the center image was like with my Ref 3.1s. I do remember all I seemed to hear was the treble. It was just too audible over the rest of the speaker. Dispersion, shmersion.

Never heard VMPS, though I've always really wanted to! Anyone in Boston want to share them? I'll bring my Mini/KEFs over! Well, maybe in a couple weeks: I've got a visitor who will be quite unhappy if I don't spend 100% of my time with her!

Well, she is my fiancée ....

[rydenfan]

This has become a great thread! Albireo and I have carried on some conversation privately over this topic and I am thrilled to see others taking an interest as well. For those that do not know on my speaker search I am narrowed down to three choices: The Revel Studio 2's, The KEF Reference 205/2's, and the SP Tech Continuum 2.5's. So this topic hold great interest for me. I look forward to auditioning the SP Techs soon; likely a combination of RMAF and visting Ted's (thanks to his gracious offer).

[konut]

FWIW, the beauty if the SP Tech design is CONTROLLED dispersion. Not so wide that wall and ceiling reflections become problematic, and not so narrow that the "head in a vice" paradigm is dictated. With the control is an even frequency response throughout the angle of dispersion. This is what gives that stable center image. That, and the balanced power response in the transition from woofer to tweeter, is the genius of Bob's design. Its all in the geometry of the waveguide/horn and crossover. Those of us fortunate enough to haved owned, and auditioned, numerous speakers know how rare it is to experience a design that gets most everything just right.