BRJ asks:
Carl V wrote:
Solo brass was also demo'd to demonstrate "the wood" effect i.e., absolute poarity.
What is the "wood" effect, and why is solo brass a good demonstration of it?
Thanks!
<<
at the bottom of this post I've cut-n-pasted from a Stereophle test disc. CD-1--Ralph the dog disc>>
As I stated in the first post...during the recording process Sound hitting the micorphone's diaphram-creating the +/- waveform & playabck 'same' waveform being amplified/modulated-- there is just one 'correct ' absolute phase with respect to the original event.
Whether or not you can hear this is up for debate. Many would say
in theory it should matter, yet in practice it won't. Some others would say active listening is an aquired or 'learned' skill. That once you've trained yourself/ears to hear certains things you can readily distinguish
distortions etc. There are a number of CDs available that can help tutor you on 'how to listen". They are often available in the back of
MIX magazine,
Recording Musician magazines. John Marks of Stereophile has mentioned this in one of his monthly columns. Dr Floyd Toole has also emphisised the value in using trained listener's. The Klippel site has a self test available on line which tests your abiltiy to hear decreasing amounts of harmonic distortion (it's humbling). I can tell you that putting in some practice time with these test/training discs will yield results.
And as to why solo brass instruments....well, as it was demonstrated that
sustained trumpet tones...trombone...french horns can point out weakenss in the XO as well as the drivers'. Also the KISS (
keep is simple) principle comes into play. You can concentrate on distinct musical lines better when there is less going on...such as an Orchestra at full cry in a crescendo. Also Brass instruments have tremendous Dynamic range.
Cheers
carl
Quote from
StereophileTrack 8 features an "absolute phase" demonstration. The sound starts out with its overall polarity one way around, but finishes with its polarity inverted. According to many writers, especially Clark Johnsen in his book The Wood Effect (footnote 3), the sound of human voice and many instruments will be more natural with the polarity correct—ie, so that an acoustic compression that reaches the microphone will be reproduced as an acoustic compression that reaches the listener's ear—than it will the other way. We have no idea which way 'round on Gordon's recording is correct, but as we have inverted the polarity somewhere in the middle, you will be able to hear for yourself if there is an audible difference between the two states. And can you identify where the change in polarity occurs?
--------------------------------------------------------------------------------
Footnote 3: Clark Johnsen's excellent The Wood Effect is available from The Modern Audio Association, 23 Stillings Street, Boston, MA 02210. Tel: (617) 357-8040. Price: $7.95 plus $1.05 shipping and handling.
