Worth taking a look at posts on 13 Oct onwards on this thread from the archive - https://forums.naimaudio.com/topic.php?p=51&oid=22544475921141560&coid=159503632588889
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For clarity, Iām the provider of the Exakt filters mentioned in the article in the OP.
First, some clarifications:
The filters in the article are for SBL Mk1s. To get there, the speakers need to be physically measured and added to Linnās database - this permits 2 things - the use of SPACE in v1 or v2 and forms the basis upon which Exakt filters can be built.
Exakt filters need electrical measurements of the drive units, some T-S calculations and the ability to upload these into the Linn Exakt design tool, along with a starting point for the crossover points & slopes and attenuation of the tweeter.
From there, listening helps to determine the best crossover roll-off frequencies and the steepness of the slopes, along with a more precise value for tweeter attenutation. This activity takes between 15 and 30 iterations - this includes overshooting the sweetspots and then working back to them.
There are no Linn āpre-setsā the filters are designed from scratch based on the electrical measurements of the speakers and lots of evolution and listening. The basics of the electrical measurements are not changed during the design process as they define the behaviours of the drive units themselves and sort out the in-driver phase distortion. The change / listen / change process is about the crossover points, slopes and relative volume levels of the drivers. Step filters are also added for baffle step anomilies when required. A geometric calculation based on an average distance listening position also permits drivers to be better time-aligned.
To use the filters the system needs to have a Linn DS, DSM or System Hub with an Exakt output (Majik, Akurate and Klimax versions are available) and an Exaktbox - Akurate and Klimax versions are available without amps, an Akurate version is available with amps built in (an earlier iteration is available in Majik form and a used example is the most cost effective way into Exakt as it includes enough DACs and amplifiers to power 2 to 4 way speakers). The DSM or System Hub is a streamer and pre-amp and can accept analogue and digital source inputs. Outputs from Exaktboxes are single-ended phono and XLR balanced at Akurate level and balanced at Klimax level.
If using a non-amplified Exaktbox, the choice of power amps is entirely down to the system owner. In the article in the OP, the power amps are 250 chrome bumper.
Note that SPACE v1 and (currently in Beta) v2 are available for Exakt systems including the SBL and other filters not provided by Linn - changes such as these are independent of the Exakt filters - they donāt need to be re-written.
Pretty much any passive speaker can have Exakt filters designed for it - most need physical modifications to by-pass the passive crossover and possibly add more terminals to the connection panel, but the older Naim speakers such as SBL and SL2 donāt need physical modifications as theyāre already designed for easy conversion to active.
The gentleman who wrote the linked article is happy to have visitors to have a listen - heās in the Birmingham area.
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For more clarity, Iām the guest contributor in the OPs link 
As I said in the article, if you thought going from passive to active with a SNAXO was a big stepā¦ from SNAXO to Exakt is like having seven league boots on! Really, itās that good.
The beauty of using an Exaktbox is that you can use whatever power amps you like. Before going down this route, I had a (non Exakt) demo at a dealers of a Linn ADSM Kat into a Naim 250 vs Akurate 2200 into Kudos S20As. To me the Linn power amp laid everything out before you as though dissected on the table with great precision, whereas the Naim 250 give me a musical performance, with the spotlight on whoever in the band was taking the lead at a moment in time.
So for me, to be able to use Exakt technology with a pair of Naim 250s is a match made in heaven.
If anyone would like a listen (@yorkshireman or anyone else) and I can demonstrate passive vs Exakt Aktiv, just get in touch. Iām in West Midlands, 10 minutes from J5 or J7 M6
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SO v2 supports all speakers that are supported in v1. Including the SBLs.
SOv2 is fully operational on analogue output DS and DSM products and is in beta for Exakt DS and DSM.
Yes I use SOV2 on DSM analogue out for my passive Spendors and they sound superb and, hopefully if nothing breaks, will last me until the end of my days. I thought SOV2 was a nice improvement on SOV1. I didnāt realise SOV2 supported SBLs so thanks for putting me right on that.
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Hi Gidders, can you flag this post and send a message to Richard Dane about passing your contact details onto me.
The flag button is at the bottom of the page just bellow: This topic will close 2 months after the last reply.
Thanks
Yes I did thank you. I will be contacting you shortly.
Quite a way with words:
āIMO, the Linn Exakt system is the best looking system Iāve seen and it is superb in terms of sound quality, but it is not NAIM and doesnāt sound like a Naim system. I wouldnāt try to answer which sounds better as I think both are fantastic. And then there is Chord Electronics.ā
Just surfing the web and entered Naim active system.
Happy holidays to all!
Enjoy Your Music, The Why.
Allante93!
PS. Like many on this forum, Iāve resided with Naim & Linn. Chord may sound fantastic, but itās not easy on the eyes. 
JMHO!
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A Big Thank You to gidders for inviting me to have a listen to his active system last Saturday using a Linn Exaktbox digital crossover into two Naim 250ās, SBLās, a Linn digital streamer and a Itok, Troika LP12.
A Top Chap and a credit to the Naim forum. Very knowledgable and helpful.
We started by listening to his SBLās with the Naim SBL passive crossovers and then listened to the same two tracks using the Linn digital crossover.
The Linn Exactbox digital crossover allowed him to slightly tone down the forward nature of the SBLās.
He also added a two driver sub unit which subtly extended the bass of the SBLās and they definitely benefited from the addition as anybody who has had SBLās will know they have good bass but do benefit from just a little more in the very low frequency that they canāt quite achieve, the sub was turned on and off to hear the subtle difference that there addition made.
The first half was all digital music which was either held on an external hard drive or streamed through his Linn digital streamer.
All sounded fantastic, very detailed with great separation between instruments and vocals but remaining musical without being too analytical.
We also listened to some vinyl on his Itok, Troika LP12 and also did some direct comparisons between digital and analogue vinyl music.
We also discussed the systemās power supply which was a separate mains spur.
The Linn Exactbox digital crossover could be controlled and finely adjusted using a computer program which meant that new adjustments or pre saved filters could be selected in real time.
My overall impression was that the system sounded fantastic and that it was very well balanced and I left very impressed by what he had managed to achieve by carefully selecting a few excellent key components.
The music choices were all excellent and I came away with a few new tracks to listen to and a few new albums to buy.
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@Yorkshireman Glad you enjoyed the demo & found it useful. Donāt hesitate to get in touch again if I can help further.
@Allante93 " ā¦ Linn Exakt system is the best looking system Iāve seen and it is superb in terms of sound quality, but it is not NAIM and doesnāt sound like a Naim systemā¦"
Iād agree with you if you use an all Linn system with Linn power amps, & I guess, like you find the Linn sound a bit analytical compared with the Naim sound. If you have a read of the article linked on the original post youāll see that I was previously active with a SNAXO/Supercap. The beauty of the Exaktbox is that you can use it with any power amps. I use 2 x Olive 250s with my SBLs which enables the system to retain much of the Naim sound with the sense of speed, fun &, for me, musical enjoyment (oh & Exaktbox Aktiv trounces SNAXO active IMHO 
)
The other benefit of the Exaktbox is the potential to run any speakers Aktiv. Linn themselves offer Exakt filters for a number of speakers other than thier own, but if you speakers are not on their list, like my SBLs arenāt speakerfilters can create filters them for you as he did for my SBLs
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yeah, seems Naim dropped the ball on whole digital crossover thing.Guess they concentrate on passive these days.
I must clarify a point here.
SOv2 is in the pipeline for filters designed by speakerfilters, but Linn hasnāt got around to it just yet.
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