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A baffling “baffle” experience (and what has worldview to do with audio?)

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  • douglasm6
    Hallo all (...after a long work induced absence. I have been following posts with interest, and was tempted to contribute to the Pascal s complaint thread
    Message 1 of 2 , Nov 2, 2005
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      Hallo all

      (...after a long work induced absence. I have been following posts
      with interest, and was tempted to contribute to the "Pascal's
      complaint" thread – the one concerning the ontological argument and
      relevance to audio, blind testing and Truth.

      Incidently, philosophical worldview has to be entirely relevant to our
      audio approach. Worldview defined as a commitment, a fundamental
      orientation situated in the central operating chamber of self, out of
      which all thoughts and actions proceed. We all hold to a set of
      presuppositions, consciously or unconsciously, consistently or
      inconsistently, about the basic constitution of reality. It provides
      the foundation on which we live and move and have our being.

      Am I a Naturalist/materialist? or am I one of its logical offspring,
      a solipsist/nihilist. Is everything material an illusion as in
      Eastern monism? I suspect that most people in the western world are
      postmodernists.

      Or do I hold to the view that the cosmos is a uniformity of causation
      in an open system, making it possible (in the philosophically
      consistent sense) to hold to universals/absolutes such as true Truth
      (as opposed to the postmodern use of the word "truth"), beauty,
      musical harmony, and laws of identity, noncontradiction and the
      excluded middle? Or do I borrow and poach from this worldview,
      wittingly or subliminally, pretending that these are valid, while
      intellectually subscribing to secular humanism?

      That we think we really can know anything truly, including in audio,
      is dependent on worldview and will affect our desire/motivation to
      measure and advance in science.)

      I would like to share with you an experience I have just had with the
      stands for my SHL5s and invite your comments and or explanation.

      Up until very recently, I have seated the speakers on pillars 60 cm
      high and made of brick and mortar filled with cement. Steel sleeves
      isolated from the pillars by a layer of foam provided aesthetic, WAF
      and resting plate for speakers on globules of Blutack. This was done
      because of the presence of young children and these monoliths were
      successful in that not once did they move or tip over! 120 kg (260
      lb) each.

      Sonically? ………….. well, read on.

      Now SHL5s are placed on Blutak globs on wicker platform spanning the
      tops of 70 cm high open wire frame (thick gauge) supports bought for
      $32 (They were designed as wicker drawer sets – I, of course, whipped
      out the drawers which my wife wanted anyway. So I could say that they
      cost me nothing in a sense. There I go again justifying another audio
      expense.) Slightly flexible, so that the speaker-floor interface is
      "soft".

      Now I have known for a long time about baffle–step. How this is
      catered for in crossover design is well described by Alan Shaw:

      www.harbeth.co.uk/designersnotebook/chapter5/chapter5-3/index.php

      The decision to use pillars initially was knowing made that this is
      not ideal wrt baffle–step.

      Alan designed the crossover to counteract the boost in freq > 300 Hz
      relative to lows in moving from a "infinite" baffle to box enclosure.
      What I expected, therefore, by placing the speakers on the pillars was
      a boost in the bass and low mids relative to higher up as a result of
      moving back to a bigger baffle in effect.

      How did it sound?

      A. Bass sounded rather anaemic, boring – there, but not enveloping
      like others report the SHL5 to be capable of.
      B. Mids sounded a tad thin – not how Harbeths are meant to.
      C. Most disconcerting was that fortissimo vocals, female and male, had
      a hard edge - noticeable at quite low volume and downright unpleasant
      at higher listening levels. Sibilance seemed too prominent too often
      across the recordings I have.

      This was unexpected ito my understanding of baffle-step.

      Re C above. I never questioned Harbeths QA and design. C went
      against everything about Alan Shaw's goal and achievement (and A and B
      for that matter.

      It seemed to me that the hard edge (apparent with vocals and surely
      affecting instruments' reproduction too) was a high frequency thing
      and, almost unconsciously I ruled out mentally that this had anything
      to do with my extended baffle problem, according to my understanding
      of the theory.
      I ruled out room effect. While not perfect, 1st and 2nd reflections
      were largely addressed except for the ceiling – strategically placed
      pillows, bookcases etc. Clap test sounded OK etc. (Thanx for the tip
      Alan Shaw, many years ago).
      I questioned whether inadequate recordings were the issue. Certainly
      in some they could be contributing. But this hard edge was detectable
      on every vocal recording I could lay hands on.
      Then, there is natural distortion as the voice approaches maximum
      loudness. But vocals sung loud just did not correlate with live
      experience.
      So, I began to question my equipment upstream of SHLs.
      Sony SCD-777ES ----> Plinius 9200. Surely not the Plinius, he thinks.
      Maybe it is the CD player. I posted on the forum and got the answer
      that siblilance was most likely a digital artefact - DAC distortion.
      But surely the 777 is not THAT bad, he thinks. Measures low jitter
      even by todays stds. Why has no-one noticed this with this machine
      before? What I am hearing is what people describe about the speakers
      they left for Harbeths – Kevlar cone cracking / breakup. Maybe
      everyone with Sony 777 that I have read have speakers that produce
      hard edge, he thinks, so that they cannot discern. Maybe there is a
      fault with my particular 777ES - I have a clunker?

      And then ……….common sense, engineering acumen, scientific method prevails:

      Change what you know to be wrong. With the stand change and in the
      same locations left and right:

      A. Bass is far better, full and warm, without being loose. OK I am
      close to the side-wall and corner – asymmetrically (to counter the
      Allison – 40cm to side, 70 to back, 100 to floor, and 150 cm to
      ceiling ). This was also because of the WAF and to get away from the
      cabinet betwixt the speaker as far as possible).
      Does any one know way the bass response is so much better – no
      suckout? This is counter intuitive wrt baffle step.

      B. Mids are better fleshed out and cleaner. Everything seems to be
      more relaxed. Again any thoughts?

      C. The "hardness" on vocals has vanished. It appears that the extra
      baffle was adding this degree of hardness. Sibilance, while still
      noticeable on quite a few recordings is certainly not as obtrusive and
      is largely tamed. Any explanations?

      Lesson learnt. Use speaker as Alan designed. The baffle-step issue
      is SIGNIFICANT.

      If I can work out how to attach pictures of the stands I will attach.

      (Failing this, see
      http://www.smartgroups.com/pictures/openalbum.cfm?GID=742402&AlbumID=5841065&layout=&page=1&sort=ordernum&dir=ASC)

      If I get the chance to measure all of this with Radio Shack SPL
      meter, I will post the results.
    • douglasm6
      Photos of the stands are in the new album I created called douglasM6
      Message 2 of 2 , Nov 2, 2005
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