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One for the Isobarik Experts

Good Evening All,

As work seems to be picking up I'll make this post by way of waking the thread up. It is still my intention to go down the Exactbox route.

As will have been noted from elsewhere I've been using the Akurate DS/3 direct to the SNAXO 3-6/ Supercap for months now so the NAC52/ Supercap are on their way out.

I've been avoiding buying a Klimax DS/3 but gave up fighting it last Wednesday and now have it set up in place of the Akurate device. It didn't take much playing to remind me of what I heard down at Cymbiosis some while back. I will have to keep dreaming about an Organik device....

The purchase cost will be offset by the bits I'll be selling.

Isobariks are speakers that just keep giving - you just need to improve what you feed them with.

Was playing Hans Zimmer Time Inception Live track earlier - who spread all this stories about Isobariks not doing soundstage? The sound was appearing all the way from the left to right hand wall and reaching out some distance.

Regards

Richard
 
I'm a big fan of Isobariks too, once they're set up and driven actively they are simply unique and if you like what they do, there appears, to be no substitute or further improvement possible. However, they sound so good sometimes it makes you wonder what may be possible if you did try to improve them...As I guess you did.

I've heard the Akurate DS through my system and can report confidently that IMO it's not that good. It's a bit dated I guess. I've never heard the Klimax DS in my system so I can't say anything about that (other than it looks fabulous). If you're a digital only listener these days and don't require a lot of different inputs, try a simple DAC straight to the SNAXO and control volume by software. What I mean is: take out the preamp. This must be done with care so as not to put full volume through the system which WILL damage it. Taking out the preamp takes the SQ up another clear level IMHO. Streaming services can be done by a competent computer linked to an ipad/tablet that feeds the DAC over usb. You might miss Kazoo, I guess but I can recommend JRiver27. It's just a thought and will take your system in a completely different direction. But nowadays I can't see how a preamp can improve the signal, let alone be transparent.

I just had another browse of this thread and recalled you replaced the B139s with the TDL bass drivers. Now that that you've had them a while what is your overall impression of the bass presentation and was there anything you missed about the B139s?

I'm desperately trying to free up some time to fix my Aktiv crrossover which I deliberately damaged in a moment of madness. In case you're interested it's described here:

https://pinkfishmedia.net/forum/threads/linn-aktive-crossover-repair.254426/

I'm hoping I can repair it, I've just completed receiving a long list of spares (nearly £250 worth) for the marathon repair. I'm looking forward to firing up the Isobariks again. I'll have to open up the LK280 and have a look there too as that's what instigated my meltdown in the first place.


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nostromo said:
I'm a big fan of Isobariks too, once they're set up and driven actively they are simply unique and if you like what they do, there appears, to be no substitute or further improvement possible. However, they sound so good sometimes it makes you wonder what may be possible if you did try to improve them...As I guess you did.

I've heard the Akurate DS through my system and can report confidently that IMO it's not that good. It's a bit dated I guess. I've never heard the Klimax DS in my system so I can't say anything about that (other than it looks fabulous). If you're a digital only listener these days and don't require a lot of different inputs, try a simple DAC straight to the SNAXO and control volume by software. What I mean is: take out the preamp. This must be done with care so as not to put full volume through the system which WILL damage it. Taking out the preamp takes the SQ up another clear level IMHO. Streaming services can be done by a competent computer linked to an ipad/tablet that feeds the DAC over usb. You might miss Kazoo, I guess but I can recommend JRiver27. It's just a thought and will take your system in a completely different direction. But nowadays I can't see how a preamp can improve the signal, let alone be transparent.

I just had another browse of this thread and recalled you replaced the B139s with the TDL bass drivers. Now that that you've had them a while what is your overall impression of the bass presentation and was there anything you missed about the B139s?

I'm desperately trying to free up some time to fix my Aktiv crrossover which I deliberately damaged in a moment of madness. In case you're interested it's described here:

https://pinkfishmedia.net/forum/threads/linn-aktive-crossover-repair.254426/

I'm hoping I can repair it, I've just completed receiving a long list of spares (nearly £250 worth) for the marathon repair. I'm looking forward to firing up the Isobariks again. I'll have to open up the LK280 and have a look there too as that's what instigated my meltdown in the first place.


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Click to expand...

Just looked at that thread. I don't know what you've read about repair damaged PCB tracks like that but I have had to effect repairs to the desulphators I used to sell on many occasions.

Gently scraping the green 'masking' off the underlying track will give a more than suitable surface to solder to - ideally you then need to provide some 'mechanical' support to stop the wire moving. Life gets a little more difficult it they are plated through holes but insertion of a (glued) terminal pin can get around that.

I did start a thread on the Naim forum about bypassing that NAC52/ Supercap but, as you might expect, it bought up conflicting views on the merits or otherwise.

I have done months of listening and, to my ears, I prefer the streamer direct to the SNAXO 3-6/ Supercap.

I have only used the Keltic bass units so far. The problem in comparing is that I don't have a pair of 'stock' Isobariks to compare them against. As detailed previously in this thread having gone for a pair of the very late Kustone version of the Isobariks they do present a problem in changing out the B139's in that the IMF/ TDL drivers are much deeper (as are the new B139's from Falcon).

I think I can say quite confidently that these deeper chassis'd drivers will simply not fit these later cabinets. I had to shave the edges off the Kustone blocks to get the Keltik's in........... maybe I should ask Simon Hamnett?????? If I were to try I would probably take one of the cabinets to the firm that machined the driver apertures for me as I think there is no way you can avoid removing some part of the rear 'baffle' the rear bass driver is attached to. I had ideas of making a 'reproduction' model of the lower cabinet c/w Kustone blocks on a bench so you can actually see all around.

In answer to your question I'm not sure I can entirely separate the performance of the Keltik's but the bass is definitely simply 'better'. Whether this is simply attributable to the driver or the fact that both drivers have their own channel of amplification is anybodies guess.

Regards

Richard
 
I think Simon Hammnet did that modification on an older pair, in which cotton bags of wool were used. I'm guessing he either squashed the bags a bit or perhaps simply removed one or two. The kustone blocks are properly glued rather than stapled so shifting those would be harder. You're solution of simply shaving off a sliver is a good one imo.

I did hear/read somewhere that building Isobariks was getting so expensive for Linn that they needed to simplify the task and Kustone foam was easier/quicker (perhaps cheaper) than bags of wool to fit.

On older models some space was needed down there to house the crossovers and later models had a small section accessible from the bottom. A good friend on mine (also a customer of Simon) has fitted the newer Falcon B139s and it was a bit of a squeeze but he just moved the cotton bags. I've heard his and the new B139s are really really good on SQ and well priced too. So driver replacement for Isobariks is now not an issue.

I've started my crossover repair and what you recommended on scraping the protection layer is how I'm doing this. I've gone for a different approach to glueing in posts. I'm taking pictures of the repair and will update my thread in the DIY section. It's a radical solution with a new breakout box housing all the xlr sockets attached obove the Active LK type chassis and all new cables (Van Damme tour cable). I want to make this repair as solid as I can. Its a bit hair raising the care and nimble finger work required... Feels like brain surgery for the un-initiated
 
Good Morning All,

Having finally decided I needed to go to the 'next level' with this project more progress, of sorts was made yesterday.

I decided to give the LP12 a listen through the Klimax DS. It did seem to take me a while to get the streamer to 'activate' the Exact 1 socket but after several attempts I got there.

Interesting to see how, essentially the same Katalyst DAC architecture(????????) in the Akurate/ Klimax DS does something wholly different in terms of audibility! I am already determined the LP12 is going but I was wondering what a full blown Klimax LP12 could do?

With the help of Neil Hallworth and the loan of my son's Windows laptop I now have a copy of Songcast up and running and it can 'see' the DS.

Later this morning I will be contacting Hi-Fi Corner in Edinburgh about the loan of the 10 channel Exactbox.

Regards

Richard
 
Good Morning All,

Well that's the 'loan' 10 channel Exactbox order placed.

Initially I had planned on sticking at just the six channels and ordered 6 cables from Dave at Flashback. I already have another four identical phono sockets to the ones Dave used and was hoping to use exactly the same cabling Dave had used from them to the Neutrik NC3MX XLR's to feed the necessary signals in to the 4off NAP250's driving the four mid and four woofer drivers.

Thus my post elsewhere. I have cable which will do but if the stuff Dave was using is readily available.........

Next up is seeing how to input a REW file into Songcast in to the Klimax DS.

Regards

Richard
 
Good Evening All,

The good news today:-

1. The dealer has received the 'deposit' for the Exactbox - currently waiting on notification it's en route
2. After re-locating the kitchen router to the Hi-Fi Room I'm now able to output from the Windows laptop to the DS via Songcast so we know we can get REW files into the system

The bad news today:-

1. After being submitted for its MOT the Defender needs a new shock absorber, link arm and four new tyres
2. One organisation declined to hire me a dissolved oxygen meter when advised I wanted to use it to measure the levels in my sewage treatment unit.....

Regards

Richard
 
Good Evening All,

Things are moving ahead slowly. The Exactbox was delivered by Adrian, the DPD driver, just before lunch.

designacable confirmed the four cables I ordered were posted yesterday so could be here tomorrow. Not being sure this would happen I've started modifying Flashback Dave's cables using the parts already ordered.

Wqij4d5.jpg


The SNAXO is still connected at the moment and the head torch is to try and see what is going on at the back of the amplifiers - I need to make sure the right things get connected up.

oGVkCR2.jpg


This is the 'donor' VDL cable ordered from RS along with the RCA phono plugs

ts8SiQM.jpg


One of Dave's cables modified.

Ndi6dxD.jpg


One of the two Flashback cables that don't need modifying as the tweeters are wired in series so only require one input. This one marked up already to show what connects where.

GJZqMTN.png

Neil Hallworth's idiot proof wiring guide.

INLmgE7.jpg


Gratuitous shot of the KDS/3..........

Hoping to have everything connected up tomorrow in readiness for a pre-arranged Zoom call with Neil on Saturday morning......

Regards

Richard
 
Last edited:
Good Afternoon All,

Just about ready to throw a total tantrum this morning and phone ee and swear repeatedly at whoever answered the phone about their absolutely s**t mobile signal as things have been utterly abysmal the last couple of days. A streamer really isn't a lot of use when your trying to access Tidal with near zero internet..........

Instead I decided to get the 'old' Huawei router out and press it back in to service and the normal level of access has been resumed............

That's the Exactbox wired up now having connected up one driver at a time with only the one amplifier powered up.

Initial listen shows the lower bass to be more defined/ controlled, overall possibly a bit 'bright' at the moment but still sounding pretty good.

Custom made cables due tomorrow but what I have works well enough.

All set for the Zoom call with Neil tomorrow.

1v5G0qK.jpg


As you can see this active lark isn't exactly cable free............

Do I move the SNAXO from off the top of the Exactbox???

Regards

Richard
 
cctaylor said:
....and thought setting up a 32, NAXO, 2 X SNAPS and 3 x 250s into unmodified Isobariks was a challenge!

Well done!
Click to expand...

A fair amount of time was spent checking the cables which I'd modified twice (once last night and again this morning) and then the actual double/ triple checking of which cable went where followed by very careful testing (Linn only use a low level test signal anyway).

Woodface said:
It’s an incredibly complicated way of listening to an active set up. Hope it ticks all the boxes.
Click to expand...

So do I!!!;)

I've set up the UMIK microphone and REW software (reminding myself how it all works again) and taken a preliminary set of readings which I'm just sending to Neil.

Not much more to do now until the Zoom meeting tomorrow morning.

Regards

Richard
 
Good Afternoon All,

Well that's a 3hr Zoom meeting with Neil concluded. There were some technical hitches but we've gone through several iterations and it's now down to me to listen to things a while.

After I've finished lunch and a mug of tea I need to get the speakers back in to their 'correct' positions, re-enable SOV2 and do some listening.

The cables didn't arrive today but then things tend to arrive 24hrs later out in this neck of the woods.

Regards

Richard
 
Richard, you'll need to use SO v1 in Konfig - SO v2 doesn't yet work with Exakt.Design filters. Its on Linn's "to do" list.
 
I would highly recommend Alan Parsons and Stephen Courts Sound Check either as a CD or a download. This will really check out your system to see its all connected correctly and producing all the right sounds.

There is another one I have where there's an interesting depth of field check with two microphones a man's voice a triangle and some maracas... I'll see if I can remember what it's called, its good fun too.

Edit: it's here:
https://www.prestomusic.com/classic...es-system-test-great-sampling-tracks-included
 
Good Afternoon All,

I've been away at work since Tuesday so not been able to do anymore listening so have been 'forced' to go back over things.

The first thing I've been doing is mentally kicking myself for not having taken a full REW frequency sweep whilst the SNAXO 3-6 was still connected and SO v2 in play.

The two pictures below are taken from REW files. The first is the system with the SNAXO 3-6 in play and no SO, the second is with the Exactbox in play showing the difference between SO and no SO.

lt9E0aQ.png


dOvKTVh.png


Ignore everything over 200Hz. You'll note that the same lumps and bumps occur with the SNAXO or Exactbox in play, they are room node related so you might expect this. My concern is what SO v1 is doing, or more concernedly, isn't. It reduces the 36.6Hz peak but actually deepens the trough around the 60hz level!!! It does nada about the 160Hz trough & 185Hz peak. There may be good reasons why this is but I would have expected more of SO than this.

My previous experience indicated that SO v2 was much better. I now have the capability to measure what it is doing and it will be interesting to see what differences there are when I get the SNAXO 3-6 back in play.

Neil has also introduced me to the concept of the 'house curve' which, I have to admit, was not something with which I was familiar.

Pf5SOGx.png


There is still some way to go yet...................

Regards

Richard
 
Good Morning All,

This is turning in to a very long day's oversight on this here boatie out west of Shetland. It's only 3 o'clock and I've been on the go since 9 o'clock yesterday morning - roll on retirement.

I've heard from Neil this evening and yes it looks like I might need to go back to basics. Firstly, and pretty obviously, SO can't solves dips in frequency response so it rather looks like the listening position advised by GIK may not be the best and I may have to have another go at Tune Dem with the speaker location which I thought I had 'nailed'.

I've gone back to the AMROC site to investigate where their software forecasts the pressure zones will be. As you can see from the sweep in the previous post there is a big dip at circa 57Hz.

4C6aJJ1.png


The picture above shows where the pressure zones are at this frequency. I'm not sat in any of those areas and nor am I likely to but it does mean its going to be a problem wherever I end up.

I'll need to do some experimenting with REW and find an optimal location minimising the 'suck outs' leaving the peaks to be treated by SO.

Regards

Richard
 
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