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Passive Keltiks

Discussion in 'd.i.y.' started by Jennifer F, Feb 13, 2004.

  1. Jennifer F

    Jennifer F pfm Member

    Has anyone ever come across a 3rd part passive crossover for Keltiks? How close is the Falcon Isobarik crossover to the Keltik's requirements?
    I would be very interested if anyone has any experience of this.
  2. Paul R

    Paul R pfm Member

    Linn are coy about the Keltik crossover frequencies, do you have any info?

    I'd quite like to try Keltiks, I think probably they're fashionably under-rated.

  3. Paul L

    Paul L coffee lounge for me

    I remember Keltiks coming out about two years after I bought my Briks. I couldn't afford them and it was another one of those "Here's another candy for you to aspire your now more inadequate system towards" kind of things.

    My Briks were sounding stunning but you know I was now kind of unhappy, until I actually heard the Keltiks.... and found them dull and lifeless and unmusical and wondered what it was all about. Then it happened again, and again.

    Popular myth of the time was that Keltiks were of the generation designed by committee and electronics engineers rather than acoustical engineers and they'd lost the plot.

    So, maybe they are unsung heroes and maybe not, I never did find out.
  4. James

    James Lord of the Erg\o/s


    If I got my hands on a pair of Keltiks, I could design a crossover for them from scratch. All you need is a calibrated microphone, LspCAD & computer, and a myriad of connection wires and you are set up to measure and model. You might need to read up on the subject of crossover design a bit before you make such an investment. Alternatively, someone in your area might have an interest in DIY loudspeakers and they could offer you their design service.

    Note: proper design requires measurement of both native acoustic response of the drivers in-situ on their baffles and the impedence of each driver. The computer takes care of the rest with a bit of design cunning on your part.

  5. Jennifer F

    Jennifer F pfm Member

    Paul (R),
    I must admit that I have been having those thoughts, I think that it is a speaker that has a lot of potential, it just needs a little help releasing it. It is also a lot nicer looking that the Isobarik.

    Paul (L)
    I have heard them several times including the evolution of one system. My belief is that they are particularly sensitive to positioning and crossover settings on the tunebox. They are also much better 4way active than 3 way and much better with Klouts than lk series. I have also heard them active with 135's and snaxo which was very nice indeed.

    That was about where I had got to!!! The problem is that I don't have a pair!!! I might have to try and borrow a speaker for an afernoon to make some measurements.
  6. Andrew L Weekes

    Andrew L Weekes Reverse Engineer

    If I remember correctly, Linn claimed to compensate for amplitude and phase in the XO for the Keltik, claiming linear phase for the subsequent combination, hence the active-only operation.

    This would explain the lack of info about the crossovers, in my view, it would reveal a bit too much information, maybe?

    It may also explain the dislike amongst Isobarik users; it's often my experience that upon short exposure things that are actually better can sound less exciting at first, some distortions add an element of excitement and attack, that can be very appealing.

    It's a bit like the difference between 'Briks and ESL's, I reckon both Paul and David will understand what I mean here ;)

    I have no doubt the Keltik is a more accurate transducer, as to whether it's ultimately as musically interesting as Isobariks would need some longer term exposure.

  7. Paul R

    Paul R pfm Member

    Linn definitely claim some correction for phase in the Isobarik Aktiv box, it has a lot of electronics in it. Including two rows of 8 stages of something with a capactitor and two transistors. I'd rather like to see a circuit diagram...

    Anyway they give crossover frequencies and rolloff rates in the Aktiv manual for Isobarik, but not for Keltik.

    I have both sorts of Isobarik passive crossover and an Aktiv, should the opportunity for experimentation arise...

  8. Patrick Dixon

    Patrick Dixon Imagineer

    I seem to recall a well known London dealer being less than enthusistic about Keltics, I would have expected him to have had a reasonable amount of exposure; if not quite the same as living with a pair.
  9. rontoolsie

    rontoolsie pfm Member

    Heard the Keltiks a few times at my dealer-hated them. When my 52 first came in I went to listen to it at his store before getting it home-it was plugged into the Keltiks. The sound was so atrocious I was convinced it (the 52) was grossly defective. Changing speakers proved it was anything but.

    I seem to remember hearing that Robert Richie did some modifications to them and actually got them to sing rather than to loudly groan.

    The Keltiks were Linns way of making a speaker that was far easier to build than the Isobariks with lesser quality parts, and jacking the price up to flagship levels. One of the reasons that the Isobariks and Saras were discontinued were the great amount of assembly time required and the major PITA factor when it came to servicing them. I would guess that if the Isobariks were still a current model, they would have to sell for $15k USD. And to think that when I first got into to audio I could have had a pair for a shade less than 800UKP- which was several years discretionary income at the time.
  10. Jennifer F

    Jennifer F pfm Member

    I can definately get my paws on the acitve Klimax keltik crossovers and investigate their conifguration. I think that I am still on a search for the holy grail, something as magical as the quads that can fit in a typical modern house. DBL's would be magical although there may not be anywhere to put an armchair!
    There are some amusing items on e-bay at the moment.
    gradient subwoofers for esl 67's... go on Paul you know that you want them. Also a pair of Klimax series active crossovers, currently £11 but with a reserve of £2500 hmmm. optimism.

    So any nominee's for a passive speaker that does not need a huge room and wants it back to the wall.

  11. Andrew L Weekes

    Andrew L Weekes Reverse Engineer

    For the record every pair I've heard at my dealers was dull as ditchwater too, but the exposure was short, so I can't make a definitive judgement.

    I did hear them for a whole evening once though, but playing solely classical music; it was very enjoyable, but at the time classical would not have been my choice for evaluation.

  12. Markus S

    Markus S 41 - 29

    FWIW, there was a German reviewer who was extremely enthusiastic about Linn products, giving rave reviews to any item he could get his hands on. He was running an active Keltik system. He then ditched it for a Katan/Sizmik system, claiming that the sub/sat set-up was better than the Keltik.

    Said reviewer now works as a sales rep for Linn Germany.
  13. MarkS

    MarkS pfm Member

    The two neat rows of trannies are basically cascaded all pass phase shift networks to give you time alignment between the hf & mf sections at crossover point.

    If you go over to you can read the detail of operation from the man who did the original research in the early 70's - he of Linkwitz-Riley crossover fame etc. The original full paper is available in the AES Loudspeaker Anthology first book.

  14. Arthur Bye

    Arthur Bye Member

    David C wrote:
    I've wondered about this before. Can a Isobarik Snaxo be used(or modded) for active Keltiks? If so, is there a way to run it with 4 amps instead of 3? Split XLR connectors for the bass maybe?

    I had a chance a few years back to pick up a set of Keltiks for cheap but passed them up as I couldn't get the answers I wanted about running them active with an Isobarik Snaxo.

    The Keltiks seem like a nice idea for a great speaker. I've heard so much mixed reports about them though that I've never tried them out.

    Arthur Bye

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