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Great imaging "why" theory article found...

Discussion in 'General Car Audio Discussions' started by geolemon, Jan 8, 2003.

  1. geolemon

    geolemon Full Member

    Definitely check this one out:

    http://www.nightstormer.com/imaging.htm

    This is a article that I believe to be very close to capturing the "what factors contribute to imaging", which obviously I have been experimenting with... this article was right up my alley.

    When he is talking about "fractals", and "low level' cues, I believe that to be really similar to what I have mentioned in the past.. relating imaging to subconsious cues. (feels good to find articles that seem to show you were at least somewhat on the right track!)

    I have said in the past, phasing is important.. not because it is audible (it really doesn't become consciously audible until it approaches nearly 180-degrees-out-of-phase levels), but because your subconscious picks up on the tiny phasing differences, and either perceives it as reality (and is fooled, actually sounds like there is a 3-D sound stage eminating in front of you), or else you simply aren't fooled, your brain says "this isn't real".

    I have trekked down the path that the small, basically inaudible cues that your subconscious picks up on (that you can manipulate to improve/degrade imaging) are related to very small phasing differences, phasing anomolies, the absense of any phasing anomolies (by my theory) would lead to perfect imaging.
    You can see my thought process on the matter of [absolute] phasing and imaging here:
    http://www.teamcaf.org/geolemon
    (click on the first link)

    It's not at all silly to consider that similarly, lost teeny tiny details in the music, lost either by digital encoding, or slow speakers, or cheap components, would also contribute - although I still suspect small, sometimes even inaudible phasing anomolies to be the major subconscous cues.

    Great article though, really good for any SQ freaks and geeks that you know!
    I couldn't help posting the link...

    use your imagination, and apply it to car audio!
    :cool:
     
    geolemon, Jan 8, 2003
    #1
  2. sandt38

    sandt38 Full Member

    I will have to read the article as I haven't yet, but I'm sure if you felt the urge to post it, it is a worthwhile read and I thank you Chris.

    I do have to question 2 things you say here, as it seems we may differ on a viewpoint or 2... You say that you do not notice phase differances unless they are 180 degrees off, conciously, but I wonder... are you raking into account the entire spectrum of audible frequencies?. Differant pathlengths will meet the ear at differant points, so we may have some varying frequency phase issues, while not complete 180s we will hear dips and peaks as evident, I feel in this graph.

    [​IMG]
    Adire Audio Koda frequency responce graph

    See the small peaks and valleys throughout? I almost wonder if they are variances due to the differant pathlengths as I mentioned above. While the graph is not meant to illustrate the pathlengths partial cancellation, I feel it my be as close to what I am trying to say as I will find. I do feel the readings were taken in the center of the room, rather than off to 1 side, so in car we will feel a differant scenario tthan presented here.

    For instance, I was on my way into work listening to Dave Mathews Band trying to get a feel for my stage with the new set, and I felt it was fair, but needed work. Now, Dave uses a vast amount of highs and upper midrange and deep bass (keep this is mind as I have a bit to explain in a bit). It put my stage a bit low and to the left, I knew I was going to need some work. Next I felt the urge to put in some of my daily driving music, a little 3 Doors Down, and my stage went all to hell, I mean right at chest hieght and forward slightly closer to the drivers position, actually making me move foreward in my seat!!! Now, they are more low midrange, subbass. Were they 180 degrees out of phase? I don't think so. I just think it was the typical frequency being played, while not 180 out, but still out altered my perception... I don't mean just subconciously either.

    So ? 2... Can we completely eliminate phasing anomolies? I think, my friend, it may not be possible.
     
    sandt38, Jan 8, 2003
    #2
  3. gscustoms

    gscustoms Full Member

    definatly an interesting article....
    comparing LP's to CD's.....makes you think of all the subtle things that MP3's cut off!

    and all the new music that at least to me seems like it has less life than some older CD's that i have.....maybe changes in recording quailty?

    seems like most newer music is designed to slam in either the lowbass for rap, or in the drums area for rock, almost seems excessive....like they boost those freq's so much!

    i would think that would hurt imaging too..
     
    gscustoms, Jan 8, 2003
    #3
  4. geolemon

    geolemon Full Member

    I didn't mean to imply that you couldn't hear anything other than a complete out-of-phase scenario, I said that to the conscious mind, it doesn't become apparent to our conscious minds until you start approaching 180 degrees...
    What I should have said, perhaps, is "more than 90 degrees, less than 270 degrees"

    Phasing is something you need a trained ear to know what is going on though-

    Even if you have heard two speakers with a 180 degree phase difference (ie. take your home setup, flip one speaker), it's not casually apparent why it doesn't sound as good.

    To a casual listener, it might not even be noticed... music is still coming out.
    To a trained-ear audiophile, you might know what to suspect.. but it's just suspicion even still, until it does reach a degree that it is apparent.
    And that's definitely in the "over 90, under 270" range! ;)

    Despite this seeming lack of ability in most people to pick up on this, consciously..
    even to the casual listener, if they close their eyes, they can perceive even minute shifts in phasing... not in the form of "I know phasing just changed!", but rather in the form of "It doesn't sound as realistic now... OK, now it sounds better"

    And similarly, I definitely agree with the author that your subconscious might pick up on tiny details in sound that might be completely inaudible to our conscious minds.. even those with a trained ear.

    The subconscious can pick up on lots of these things.. sort of like an acoustical sense of balance, I think.. not something that you think of consciously, not something that is apparent until you are very much OFF balance... ;)
     
    geolemon, Jan 8, 2003
    #4