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Saturday, November 12, 2016

Live from Denmark : ETF 2016 - Part 16


Yesterday evening we had a great listening session with the Norwegian gang which I want to share with you.

In a previous post I wrote already that this open baffle speaker with the many drivers perfectly represents what the ETF is all about.

This speaker was made just for the ETF. It looks totally outlandish when you first see it but it's sheer beauty simply draws you in.

Initial sounds heard from this speaker were already very impressive and there is just something right about them.

As is always happening during the ETF they kept working on them and improved them step by step.

They can swap out the high frequency section as seen here

But they went back to that white horn from the beginning and tamed it.

After the recording of the live concert Bjorn brought his reel to reel into the this room and it got hooked up to replay what was recorded just an hour before.

This was simply amazing. I am not easily impressed when it comes to audio stuff. But I was present when the recording was made and hearing it played back shortly afterwards really tells the truth. This had all the dynamics and ambience which I heard at the concert. And it was very natural and transparent:

It was such a great experience and everybody in the room was mesmerised:

This set up is really amazing. So great to see things like that made with such a passion and then expertly set up improved and brought to such a high level in just one day.

This session was my personal highlight at the ETF so far. Thanks to Torbjorn for bringing this speaker and his Norwegian fellows to set up such a system and of course to Bjorn for such this beautiful recording.

Keep up this spirit guys!

Best regards



  1. Thanks to Thomas Mayer for the very kind words and coverage of our ETF 2016 system, and for your coverage of the whole ETF. We have been as impressed with this system as anybody else, as actually it had not really been listened to before we set it up on Friday. However, it had been carefully conceived and planned by Torbjørn since before the previous ETF. Some time and experiments were needed before we settled on the best choice of HF system, crossovers etc. in place by Saturday afternoon. Thanks to Bjørn Aaholm, Lars Tørressen and Charles King for all the amazing tapes we got a chance to listen to.
    Because of unexplained response differences on swapping the LF and HF amps in the bi-amp setup, we ended up running Lars' SE 2A3 amps on the LF section (2 outer rings of cone units) and they never seemed to be running out of power, even when the system went quite loud and with a lot of bass. Also, the center LF dipole was found mostly unneccessary for sufficient bass reproduction. We brought it along almost just in case, but it was hardly used at all during the ETF.

  2. Thank you Thomas for the nice coverage. I'd like to add that the recording was really the work of Lars Tørresen. He set up the microphones and did all the mixing work. I "just" provided a freshly restored and adjusted Studer B62 and some tape :-)

  3. What type of compression driver and (white) horn combination is that in the middle? Thank you.

    1. Hi!
      I hope one of the North men Thomas Dunker or Tjorborn will answer this when they read it. I don't know


    2. Hello.
      I would first like to thank Thomas D. for giving me the opportunity to create these: He was responsible for rescuing quite some of the old Seas-units seen used in the panels.
      (While some came from elsewere, and some from the cinema I used to visit as a child, nearly 50 years ago.)Its a gift,- to be able to use such very light and suitable units in an open baffle. Most units produced later would simply have been to heavy, and so more bandwith-limited.(The cone sections were at all times driven only by a modest 1.5W, by Lars' SE 2A3-amplifier.)

      Next I want to thank Thomas Mayer for his coverage in writing and pictures, both of the ETF, and of the Norwegian system: So nice and professional work, Thank You! And thanks to the rest for making ETF such a great event.

      The white midrange-tweeter-horn used is of the late Jean Michel LeCleach-type.If I have understood right, it was a collaboration between Lynn Olson, Bjørn Kolbrek, and Azurahorns. Its a 425Hz modest Hypex-type horn, ecpecially develloped to fit the Altec 288. In the ETF-setup, a beryllium-phragmed Neomag.-driver was fitted via a thin adaptor to the throat; the JBL-2435HPL. It seemed to work fine.

      See you!, Best Regards Torbjørn Lien - Norway

    3. Thanks Thomas, and Torbjørn,

      Those Seas and cinema FR alnico drivers looks almost brand new to me.. I wonder how you configured where to put the whizzered ones and non-whizzered ones on the baffle.. Or maybe it was a random placement.

      I thought the horn was familiar. The late JMLC would be proud to have heard this system. Martin (Azurahorn), Bjørn, and Lynn should see this blog post. Lynn should also see Thomas' previous PP DHT posts.. Those pro Be JBL's sounds like a good match for the horn.

      Congrats on a fine on the "left field" Flower Power OB/Horn system.


    4. Hello Rick,
      The 10" and 8" drivers used here are all produced between mid fifties and mid 60'ies. These (motor-systems and phragms) are still basically identic, only notable difference is that the earlier 10" units (with brownish phragms, whizzerless, positioned 4 in row at the sides) has a somewhat higher Qm, whereas the later units is more edge-damped / lower Qm. (Later units, some whizzered, also have slightly harder pressed phragms, but with same mass or mass/diaphragm-area.)

      In the use here, the whizzers and various dustcaps didn't contribute to differences, as alle units was lo-passed at 750Hz. (With the 4+4 "bass" units positioned at the sides further lo-passed at around 200Hz.)

      There is not much to find on vintage Seas units on the web, but Troels Gravesen has additional info on his speakerbuilding-site:
      You can read more in the vintage-section, under the construction "Blackcones", that puts a same type 8" (As seen near the white horn) to use in a resonnant cabinet.

      Best regards Torbjørn

    5. Hello Torbjørn,

      Thank you for sharing more details. The coaxial and methodical placement, and crossover points is ingenious...

      Best regards,