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Thread: A cautionary tale of self deceit - from a loudspeaker designer

  1. #1
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    Default A cautionary tale of self deceit - from a loudspeaker designer

    We recently touched on the subject of the wild and ludicrous claims of sonic improvement made possible by changing your speaker cables. We just don't believe it, and nor do those who have conducted proper, blind listening tests. Any differences - and there may well be small differences - are likely to be speaker/amplifier/length dependent which makes universal recommendations useless at best.

    It all boils down not to the cables, but to the truly dreadful human audio memory, which is only reliable for a few seconds at best. This has been know for two or more generations and should be obvious. So anyone that can reliably make a mental comparison of two sounds separated by a few seconds will not be able to make the same reliable comparison over thirty seconds, or a minute or five minutes. Or a week or month. To make comparisons between A and B that are reliably within the human audio time zone, the switch-over comparator was invented. Even quality audio was demonstrated and sold via the switch-box (see picture). It fell out of fashion when it didn't suit the media or industry to have such black and white, go/no-go, pass/fail delineations. And that coincided with the end of the golden era of science-based audio reviewing.

    That's another story, but I wanted to tell you about my experience these past few days which proves a point. I'm not embarrassed to admit it, because I know just how as humans our senses are useless instruments because we cannot remove the emotion from the observation. Here is a case in point ....

    I don't watch much TV, and rarely a DVD but I do have a TV/DVD set-up in a spare room (used to to be the children's play room when they were small). Nobody fiddles with the system, and perhaps once a month I'll half watch something in stereo or surround, sometimes a DVD audio disk. The speakers are the NRG4 towers that we made a few years ago either side of the TV. I sit about 2m away. Now, I became vaguely aware about a year ago that the left speaker seemed a little less bright than the right, and I fiddled with the biwire links and I guess convinced myself that it was working properly. I completely forgot about it, and I've watched a few movies, many TV documentaries, DVD audio disks during the year. But finally, just before the Royal Wedding (April 2011) for some unknown reason I pressed my ear to the left tweeter - nothing. So I fiddled with the biwire links again - still nothing. Fetched a test meter and traced the wires assuming a wiring/xover fault as we'd never had a failure of the NRG tweeter. Wiring around xover good. So it must be the tweeter?

    I carefully removed the tweeter to find that the plastic moulding had failed along a weld seam and the terminals had slightly separated from the voice coil/magnet, hence no possibility of sound. And this must have happened many months - perhaps a year ago. So I have been listening to a pair of speakers with a dead tweeter on the left channel and not even noticed it.

    How is this possible? It's simple: to a large degree, we hear what we want to hear. This works for and against our listening pleasure. For because it makes the crackles and distortion of all LP listening inaudible as we marvel at the romanticism of the rock wiggling in the grove, and it works against us when we all-too-easily convince ourselves in the sonic miracle of that new (expensive) speaker cable, spikes, room-tuning bells, isolation platforms or whatever. We allow ourselves to be seduced by our own senses. And seduction can be very pleasurable indeed.

    Be warned! Your audio memory will hear what it wants to hear.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

  2. #2
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    Default Powerful self-beliefs at work in the audiophile's brain

    I would see this less as a matter of "self-deceit" than a matter of pattern recognition/construction by the brain. The brain is not simply a measuring instrument; it constructs what we experience as reality on the basis of sensory input, but not only sensory input - the construction is also based on pre-existing ideas about what we expect that our reality will consist of. Not only what we "want" to see, but also what we expect to see (or hear).

    Part of what will determine our perception is not only current but also prior sensory input - in this case, I would suspect that because your brain already "knew" what these speakers should sound like, it didn't really have to expend the effort to fully hear the sound that was there: the sensory input was close enough to the cognitive map that the extra effort was (unconsciously) perceived to be unnecessary.

    I suspect that most audio "tweaks" have the effect they do not merely because people are deluding themselves, but also because the powerful belief that the tweaks will work creates a different mental/perceptual experience than would have been the case in the absence of that belief. So true A/B testing on humans may be difficult, as it may isolate perceptual differences (or lack thereof) but won't isolate the experiential differences caused by powerful belief.

    Of course, if you can successfully change people's beliefs, or convince them to suspend their beliefs (always difficult) pending the outcome of a test, then you've got something...

  3. #3
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    Default Deaf but happy?

    The good news with Alan's story is that (presumably) if one of my ears goes I'll not notice it :-)

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    Default Two weeks out of phase!

    An honest confession only enhances the reliable status of he who makes it!

    I once listened to a pair of bookcase speakers, one out of phase, for two weeks. In mitigation I must say that I complained the whole time about their quality.

    But how could I have been so stupid? I am not colour blind, and I knew the score - I read Applied Physics and Electronics at University. I suppose that increases my stupidity!

  5. #5
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    Default My head being pulled apart = out of phase

    Out of phase speakers make me feel as if my head is being pulled apart - most uncomfortable. Some people don't appear to hear it at all for some reason.

    I once had a well respected speaker designer round to demonstrate his new speakers. He inadvertently connected them out of phase and sat there enjoying the music. When it was my turn to sit in the 'hot' seat, I immediately jumped up and swapped the plugs. Slightly embarrassing !!!

  6. #6
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    Default Sound from the wrong channel

    It is annoying. If I'm too lazy to get up and switch the plugs I just stand on my head. That usually works (until I pass out).

    Seriously, I can't even tolerate hearing the opening of Pinball Wizard out of the left speaker.

  7. #7
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    Default

    Quote Originally Posted by QChicago View Post
    I can't even tolerate hearing the opening of Pinball Wizard out of the left speaker.
    Surely you are NOT playing Pinball on a computer hooked up to Harbeths?

  8. #8
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    Default Illusion - sonic and visual

    Quote Originally Posted by Labarum View Post
    ........But have could I have been so stupid? ..........y!
    You are not alone. Unless, you sit in the sweet spot and concentrate to the music and let your brain fool ourselves in creating the 3D illusion then phase in most cases are undetectable*. You need to listen to individual instruments and let your brain to fix an arbitrary point in front of you for the imaginary location of the individual instruments.

    Once, five of us were trying to figure how many singers were there in one particular track. One of my friend couldn't hear two other singers so I went in front of the speaker *and pointed where the four singers were located. Later, when my other friends tried to identify their position we have various different points. It seems, each individual perceive the location of each singer differently. So a soundstage is as real as your brain want to make it out.*

    That reminds me, about 20 years ago there used to be a small 3D picture attached with the cigarette box. There would be a picture and at the back some dotted patterns. After a few weeks, I asked my friend what was so special about the 3D picture and it was only then my friend explained to be that I should able to see the image in the dotted patterns. Until then, the dotted pattern was without any meaning to me.

    Back to stereo playback, I believe some of listen differently. Until one pays attention to the music and visualize the soundstage you would just hear music without any dimension.

    Attached herewith a dotted stereogram which for some may look just that and for others a beautiful 3D image. ( sorry... Can't find attachment link, try here )

    ST

    {Moderator's comment: Do you really mean this (*)? If the phase is reversed on one speaker then there can be no proper central image. Your brain will not be able to create a solid image. Please clarify what you mean exactly.}

  9. #9
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    Default Absolute phase???

    I believe he is talking about 'absolute phase', where the pos and neg of both speakers are reversed.

  10. #10
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    Default Hearing ability and stereo imaging & nature ...

    Quote Originally Posted by STHLS5 View Post
    ..{Moderator's comment: Do you really mean this (*)? If the phase is reversed on one speaker then there can be no proper central image. Your brain will not be able to create a solid image. Please clarify what you mean exactly.}
    Dave and Mod, I am not referring to absolute phase but an overall stereo playback.

    We often overlooked that when it comes to audio - the final measuring tool is our ears which unfortunately cannot be calibrated like all other instruments in the audio chain. Long time ago Pluto (our HUG member) pointed out that he was told by his ENT that damages to the hearing may cause some people to have the ability to hear absolute phase. Alan too once posted that he lost a few dBs in one frequency in one of his ears which recovered later.

    IMO, it is wrong to assume that everyone's ears are functioning perfectly. A slight sinus may cause one of our ears to be partially blocked without we ever realizing. Some may able to pick out a quiet conversation in a stadium while the other thousands screaming for their favourite team. Some maybe more sensitive to low level noise than others. In short, no one's ears can be identical.

    Let's say person A ( suffering 50% hearing loss in his left ear), person B (suffering 50% hearing loss in his right ear) and person C (with perfect hearing on both ears). Do you think all these person would perceive the stereo image identical with each another? Wouldn't "A" and "B" perceive the sound to be skewed towards right or left respectively?

    Now add more variables to the A, B and C. Let's say in one of their ears suffering a slight damage where absolute phase now can be detectable. It is also has been acknowledge that people's abilities to localize low frequencies varies from person to person. Some cannot localize below 120Hz while some could go as low as 80Hz or even lower.

    In conclusion, the soundstage presented by the stereo loudspeakers varies from one person to another. AND, I am not sure that you can immediately identify if a speakers is correctly (phase wise) connected without some effort. If we were to walk in to a room while the system is playing but our mind is focused on some other things, you could hardly tell if you are hearing to a mono recording or to a stereo or even if one of speakers not working.

    It is hard to believe that our brain will allow us to perceive two identical sound emitting in two different location to be treated as one. Definitely, it cannot be part of nature's survival instinct if we were unable to differentiate two predators in the dark just because they both growl at the same time. In nature, if we see two bird singing in synchrony do we see the sound coming from the centre? How do you perceive when two violinist performing a duet? Do you just hear one sound in the center or do you consciously aware that two identical sound emitting from two different points?

    Stereo is a modern creation which was meant to fool our hearing and we allowed it to manipulate us. Ignore the stereo effects and you will just hear two sources making the same sound. In nature, when someone speaks to you, the sound comes from a single source. With stereo, the same sound comes from two different sources, doubling the path to our ears. In nature, one voice goes in to left and right ears. In stereo - left speaker's sound goes in to left and right ears and the right speaker's sound goes in the right and left ears. Can you imagine how disorienting and distorted that could be for our brains to process? Perhaps, it was no coincidence that earlier recording artistes showed dislike for stereo recordings. It is unnatural, disorienting, and undoing to our thousands of year’s evolution in hearing.

    Now, ever wonder why dual mono recordings, such as Sonny Rollins, were extremely pleasant and relaxing to listen to? But thankfully we adapted to it and enjoying them. We also enjoy lung choking cigars, bitter beers and deliberate piercing in the name of fashion. All these supposed to be against nature and self-preservation but we are doing it anyway.

    ST

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