Endgame passive bookshelf shootout: KEF Reference 1 Meta vs. Ascilab S6B

[Jiraya369]

you wont hear much except for the slightly deeper bass on the S6B and the wider horizontal dispersion, meaning a wider soundstage. That's basically it. The coaxial nature of the Ref 1 Meta means if you move your head like 40 degrees below the reference axis, you can still get a good sound, not the same thing for the Ascilab but due to the low crossover you can go quite low and still get a great sound, and vertical dispersion is top notch on both.

Get whichever is cheapest, is easiest to place and most importantly looks best. Endgame is a mindset, if you get something which looks genuinely good to you, then you're done.

Make sure to budget in some subs and measurement mics

 

[kharan]

I appreciate the response. Thanks for pointing the different test methods out.

at my small room at 2m listening distance and speaker next to wall at moderate listening levels I consider the S6B a full range speaker which for me means, besides output, also reasonably low distortion in the bass. For me it is really amazing that the S6B is able to pull that off at that size and I really like the idea of having a tiny ,,full range“ speaker.

The KEF is great until 40hz but then distortion rises. I plan on using one subwoofer to correct for front wall dip via Dirac art but plan to keep the speakers as much full range as possible. Maybe I let the sub aid below 40 hz or so.

I considered the Genelecs too and would be fine with the active nature given Genelecs reliability, but the look of it somehow bugs me too much.

The purify woofer and the bass extension is the main reason which keeps me pausing from buying the KEF. That driver truly is something special and a level above the KEF‘s woofer.

would you care to explain why exactly you liked the wide high frequency radiation?

It would be nice within this year. I don’t mind waiting for the S6B availability. At least the KEFs are sometimes avaible at the used market which shrinks the price difference at least somewhat.

Given that you mentioned a small room and 2 metres of listening distance, either of those speakers are going to be plenty enough. We don't hear distortion well at low frequencies, for example I recall that -10 dB or 30% distortion is about the threshold for 30 Hz. And if you want superb bass, you're going to need subs to deal with room nodes anyway. For music listening at normal volumes, both are going to provide more than enough bass in good enough quality. The same goes for the other distortion measurements, everything is low enough to not raise above the threshold of audibility. If your room is less than 15 sqm, there's absolutely nothing to worry about.

To a large extent, you should base your choice on how the appearance of each speaker makes you feel and how they integrate in your space than how they "sound". Without hearing them, both of them are just different flavours of "very good" with the S6B having a bit more presence and attack due to its wide bump in those frequencies. But given that both speakers have excellent directivity, you could always change that with EQ afterwards.

If you can find room for a floor stander, the C8T is your best bet considering that your side walls are almost certainly closer than you would like and reducing side walls reflections is probably the best upgrade you could do.

 

[Chromatischism]

Isn't VECO going to be for active speakers only?

This is basically the same thing as the servo that Brian pioneered at Rythmik many years ago. His system does not use any DSP; it is entirely analog and real-time. But yes, it works with the amplifier so it will not be found in a passive speaker.

The KEF version appears to be taking some extra steps. I'll need to watch the video again after I've waken up a bit to understand it better.

But notably this only works at low frequencies, which is why in the video the KEF engineers talk about the effects on bass.

 

[Ktacos]

If the choice is between a well designed speaker with purifi drivers, and well designed speaker without purifi drivers, I would pick the speaker using purifi every time. The bass distortion is like 10db lower on the ascilab. I would also pay attention to the difference in how cleanly the off axis response fades between these speakers. I'd argue the cabinet edge diffraction artifacts are much cleaner on the ascilab. Granted, all my speaker are square boxes with no roundovers, and they still sound incredible, but I do find speakers that take effort to minimize edge diffraction sound smoother and have an easier time developing a good phantom center.

Can't really go wrong with either speaker.

(not like it matters but if I were buying, ascilab, because it's visually more interesting to me. I absolutely cannot stand this trend of the look of KEF's concave woofers with surrounds hidden behind a ring. A couple other brands are doing it and they all just look like the same speaker to me).

 

[kharan]

If the choice is between a well designed speaker with purifi drivers, and well designed speaker without purifi drivers, I would pick the speaker using purifi every time. The bass distortion is like 10db lower on the ascilab. I would also pay attention to the difference in how cleanly the off axis response fades between these speakers. I'd argue the cabinet edge diffraction artifacts are much cleaner on the ascilab. Granted, all my speaker are square boxes with no roundovers, and they still sound incredible, but I do find speakers that take effort to minimize edge diffraction sound smoother and have an easier time developing a good phantom center.

Can't really go wrong with either speaker.

(not like it matters but if I were buying, ascilab, because it's visually more interesting to me. I absolutely cannot stand this trend of the look of KEF's concave woofers with surrounds hidden behind a ring. A couple other brands are doing it and they all just look like the same speaker to me).

Lol, and here I am wishing Ascilab had concave woofers and inward facing surrounds for a cleaner look.

Actually, looks wise, I prefer the looks of the Purifi fibre woofers than that of the Purifi aluminium driver.

 

[Purité Audio]

I don’t have KEFs REF1 but I have Asci’s A6B ( Purifi ) and their S6B ( all Purifi, and 2x 8” Passive Radiators ) are arriving soon.
Keith

 

[willverduzco]

Between those 2 I would choose the amazing bass extension of the Purifi woofer in the AsciLab speakers. But honestly owning my Sointuva AWG I am pretty happy with it, and I don't feel like missing out on the Purifi tweeter.

Sound power linearity is second to none.

March Audio Sointuva AWG Bookshelf Speaker Review

March Audio Sointuva AWG

www.erinsaudiocorner.com

Seconding this recommendation. I auditioned the Reference 1 Meta at the same time that I purchased my Sointuva AWG, and I preferred the overall character of the Sointuva AWG due to its significantly better bass response and better linearity. The overall tonal balance is truly second to none.

 

[Goldhamster916]

you wont hear much except for the slightly deeper bass on the S6B and the wider horizontal dispersion, meaning a wider soundstage. That's basically it. The coaxial nature of the Ref 1 Meta means if you move your head like 40 degrees below the reference axis, you can still get a good sound, not the same thing for the Ascilab but due to the low crossover you can go quite low and still get a great sound, and vertical dispersion is top notch on both.

Get whichever is cheapest, is easiest to place and most importantly looks best. Endgame is a mindset, if you get something which looks genuinely good to you, then you're done.

Make sure to budget in some subs and measurement mics

i appreciate the advice.
I am already using dirac art and have a subwoofer whose main job will be to fill in nulls.

Given that you mentioned a small room and 2 metres of listening distance, either of those speakers are going to be plenty enough. We don't hear distortion well at low frequencies, for example I recall that -10 dB or 30% distortion is about the threshold for 30 Hz. And if you want superb bass, you're going to need subs to deal with room nodes anyway. For music listening at normal volumes, both are going to provide more than enough bass in good enough quality. The same goes for the other distortion measurements, everything is low enough to not raise above the threshold of audibility. If your room is less than 15 sqm, there's absolutely nothing to worry about.

To a large extent, you should base your choice on how the appearance of each speaker makes you feel and how they integrate in your space than how they "sound". Without hearing them, both of them are just different flavours of "very good" with the S6B having a bit more presence and attack due to its wide bump in those frequencies. But given that both speakers have excellent directivity, you could always change that with EQ afterwards.

If you can find room for a floor stander, the C8T is your best bet considering that your side walls are almost certainly closer than you would like and reducing side walls reflections is probably the best upgrade you could do.

i agree that both speakers are more than enough for my current room. However i am young and want the headroom if i ever move into a larger space. I do consider the C8T but bookshelf is prefered for ästhetic reasons.

If the choice is between a well designed speaker with purifi drivers, and well designed speaker without purifi drivers, I would pick the speaker using purifi every time. The bass distortion is like 10db lower on the ascilab. I would also pay attention to the difference in how cleanly the off axis response fades between these speakers. I'd argue the cabinet edge diffraction artifacts are much cleaner on the ascilab. Granted, all my speaker are square boxes with no roundovers, and they still sound incredible, but I do find speakers that take effort to minimize edge diffraction sound smoother and have an easier time developing a good phantom center.

Can't really go wrong with either speaker.

(not like it matters but if I were buying, ascilab, because it's visually more interesting to me. I absolutely cannot stand this trend of the look of KEF's concave woofers with surrounds hidden behind a ring. A couple other brands are doing it and they all just look like the same speaker to me).

yeah that purify driver is them main argument for the S6B over the KEF. Only downside is the modulated distortion due to the 2 way nature when playing very low at higher volume levels. I cant find any MD data for the reference 1 unfortunately.

The reference 1 has a ring around the driver which is acting as an extended wave guide of sorts. in combination wit the narrow baffle it hopefully avoids most diffraction effects horizontally and maybe some vertically at the top of the speaker.

I wonder if there is any benefit of having such a smooth low profile woofer cone and ring compared to the jaggy surround and rather peaky woofer centre of the purify driver. i personally am in the opposite camp and prefer the clean look of the reference 1 woofer implementation.

 

[Goldhamster916]

Seconding this recommendation. I auditioned the Reference 1 Meta at the same time that I purchased my Sointuva AWG, and I preferred the overall character of the Sointuva AWG due to its significantly better bass response and better linearity. The overall tonal balance is truly second to none.

good to know that you auditioned both and preferred the purify design. I think about getting the reference 1 used for a good price so i can resell it without a loss and then order a S6B from audiophonics once avaible and return it if i decide to go with the reference 1. Although i dont really like the idea of shipping multi thousands dollars speakers back and forth. apart from not having the money to have both simultaneously...

 

[Jonazkur]

Ascilab s6b is way better value. Less diffraction and better bass.

 

[phoenixdogfan]

You are leaving out the ASCI A6b. On measurement for measurement the A6b almost exactly replicates the performance envelope of the Reference 1 except it goes slightly lower in the bass. Anyone who wants to can look at Pierre's site and look at the two speakers' overlaid measurements. Everything from on axis, to listening window to reflections, to sound power and the two directivity measure are virtually identical copies of one another. Check it out.

And. really, the only significant difference between the A6b and the S6b is the wider horizontal dispersion of the S6b, particularly in the treble of the latter. That may or may not be something preferred by a given listener. It is, IMHO, a matter of taste and the size and reverberant nature of the room the speakers are playing in. And the wider dispersion in the high treble? Most listeners, particularly older audiophiles, won't even be able to hear it.

 

[AudioJester]

Seconding this recommendation. I auditioned the Reference 1 Meta at the same time that I purchased my Sointuva AWG, and I preferred the overall character of the Sointuva AWG due to its significantly better bass response and better linearity. The overall tonal balance is truly second to none.

The Purifi tweeter is audibly superior to the SB Acoustics, but you would only realise this comparing side by side.
March demonstrated this at audio shows in Aus last year, the difference was pronounced. Obviously anything Purifi comes at significant cost.
The S6B looks incredible

 

[Goldhamster916]

You are leaving out the ASCI A6b. On measurement for measurement the A6b almost exactly replicates the performance envelope of the Reference 1 except it goes slightly lower in the bass. Anyone who wants to can look at Pierre's site and look at the two speakers' overlaid measurements. Everything from on axis, to listening window to reflections, to sound power and the two directivity measure are virtually identical copies of one another. Check it out.

And. really, the only significant difference between the A6b and the S6b is the wider horizontal dispersion of the S6b, particularly in the treble of the latter. That may or may not be something preferred by a given listener. It is, IMHO, a matter of taste and the size and reverberant nature of the room the speakers are playing in. And the wider dispersion in the high treble? Most listeners, particularly older audiophiles, won't even be able to hear it.

I am willing to spend this kind of money and want it to be as good as possible even if the differences are rather minor.

 

[kharan]

The Purifi tweeter is audibly superior to the SB Acoustics, but you would only realise this comparing side by side.
March demonstrated this at audio shows in Aus last year, the difference was pronounced. Obviously anything Purifi comes at significant cost.
The S6B looks incredible

I've yet to see measures proving that any superiority that isn't due to a different directivity and that reaches thresholds of audibility at normal listening volume.

I am willing to spend this kind of money and want it to be as good as possible even if the differences are rather minor.

IMHO, the difference is somewhat larger that it would seem. I said the Purifi tweeter wasn't superior to the SB Acoustics one audibly, but it does allow some amount of design freedom that wasn't possible with the SB Acoustics. Ascilab managed to get wider directivity in the midrange from the Purifi driver waveguide combo that isn't there on the SB Acoustics driver and waveguide combo. IMHO that 60° directivity in the midrange is a noticeable change, can't say better or worse, but certainly noticeable. This usually contributes to a wider soundstage.

Then because it's wider in the midrange, this allow better integration with the midwoofer, there's less discontinuity there.

Another thing is that the SB has a slightly larger cabinet, 26L instead of 22L, with larger passive radiatiors. You just need to check the distortion figures between the S6B and the A6B, there's a very noticeable improvement.

 

[Matias]

Note that there are different SB Acoustics tweeters available: the one on Sointuva AWG is top in their line than the one used on A6B.

 

[Defi]

Honestly I don't know how a non-cardioid speaker could look better than the S6B measurements. I guess if you wanted to nitpick the vertical dispersion having some ups and downs, but the only vertical dispersion better than this i've seen is coaxials and I like that the S6B is narrower in that regard. I have been planning to get the C8C but I am sometimes tempted by the S6B.

 

[thunderchicken]

I was in that particular pickle and having experience with the LSX and Q1 Meta, I went with Ascend Acoustics’ Sierra LX. The wait for AsciLabs was going to be too long. Glad with my choice!

 

[Jonazkur]

Note that there are different SB Acoustics tweeters available: the one on Sointuva AWG is top in their line than the one used on A6B.

Imo the March Audio sointuvas tweeter narrows too quickly in the top end. The wg on that tweeter isnt optimal.

 

[Matias]

Imo the March Audio sointuvas tweeter narrows too quickly in the top end. The wg on that tweeter isnt optimal.

I gladly chose narrower highs dispersion to get the very best in room linearity. If someone else chooses the opposite, it's a preference thing. Like aesthetics, there is no right or wrong, just preferences.

 

[jonfitch]

Imo the March Audio sointuvas tweeter narrows too quickly in the top end. The wg on that tweeter isnt optimal.

I like that Ascilab, while they also use OEM drivers, do additional modifications like adding custom waveguides and acoustic lens to improve the performance. The Satori driver on the Sointuva would benefit from a custom acoustic lens on top of the tweeter to broaden the dispersion in the higher frequencies.