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More Distortion? Yes Please!

Posted 3rd June 2011 at 04:58 PM by Pano

Can High Fidelity include audible distortion?

From the ultimate heights of fidelity we should hear a perfect reproduction of the recorded signal all the way from source to speakers – right? Perhaps that depends on your idea of fidelity. Where does your fidelity lie? What are you being faithful to? To the recorded waveform, or something else? Could your idea of fidelity be that you want the final result to be faithful to the direct sound of the music? Is your goal a faithful reproduction of the music, or of the recorded signal? The two are certainly not mutually exclusive, but can often be at odds.

Low distortion is the second of the two founding pillars of HiFi - frequency response being the first. Any distortion alters the signal, therefore it must be wrong. Or so says conventional thinking. To be highly faithful to the signal, we must alter it as little as possible, granted the possible exception of overall level or volume. But what if our goal is not the most faithful reproduction of the signal itself, but of the original sound? How much does distortion matter in that case?

For years on this forum I and others have talked about inaudible distortion. There are numerous studies going back to the 1930s that show certain forms of distortion are inaudible, by ear you simply can't tell them from a pure sine wave. You may be able to measure them, but you can not hear them so they simply don't matter to the ear. There are other forms of distortion that can be heard even in tiny amounts and they do matter. Many tube amps and speakers produce large amounts of inaudible distortion, many solid state devices produce significant levels of audible, and often objectionable, distortion. Of course both types of distortion are present in tubes, speakers and solid state, so it's not an either/or situation. HiFi life isn't that simple. Euphonic distortions, harshness, warmth, cold, lifelike, accurate, etc. We've all heard these.

Now follow me out of the box and onto a shaky limb for a few moments. What if audible distortion actually helps audio reproduction? Could certain distortions bring our perception of reproduced sound closer to what we hear live? We know that electric guitar players love distortion and that sound engineers often use it live or in recordings to achieve the sound they want, but what about in reproduced music? Could audibly distorted playback be closer to the "real thing" than a purer version? I don't mean simply "sounds better to me" but actually more faithful to the original sounds.

Let me frame the question in a different way. Can you imagine a case in which a distorted signal can give a more realistic, more accurate perception of the original than an undistorted version? Or a case where perfectly undistorted signal does not give the most accurate perception? You may be shaking your head "No." You are invited to grab your mouse and keyboard and do a little research on the "Globe Effect." It's not Shakespeare, it's optics. And although it is optics and not acoustics, it may just open your mind a bit to the possibility that perfect is not always correct.

I'll be back after you've done your reading and thinking.

"Please sir, I want some more." said little Oliver Twist.
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Comments

  1. Old Comment
    SY's Avatar
    Quote:
    Can you imagine a case in which a distorted signal can give a more realistic, more accurate perception of the original than an undistorted version?
    Sure. Dither. Dolby and DBX encode/decode. Just off the top of my head.
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    Posted 3rd June 2011 at 07:31 PM by SY SY is offline
  2. Old Comment
    Pano's Avatar
    Good examples, thanks.
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    Posted 3rd June 2011 at 08:54 PM by Pano Pano is offline
  3. Old Comment
    kevinkr's Avatar
    Dither is a good example, but Dolby and DBX are complementary processes - the resultant signal is supposed to be an unaltered replica of the original signal prior to processing. Listening to said signal without applying the complementary post recording processing can be quite nasty from direct experience in particular with DBX.

    FWIW I had an early undithered demo CD from Philips when I bought my first CD player back in 1984. Sounded quite unnatural due to the lack of natural low level reverberation and in particular the decay into the noise floor at the end of a song - just truncated.

    Another example might be the substantial amount of 2nd harmonic added by most conventional SE triode amplifiers that many of us either don't notice or actually prefer.
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    Posted 4th June 2011 at 12:11 AM by kevinkr kevinkr is offline
  4. Old Comment
    Pano's Avatar
    Yes. And why might we prefer it?
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    Posted 4th June 2011 at 12:28 AM by Pano Pano is offline
  5. Old Comment
    SY's Avatar
    Why do people prefer compression and "aural exciters"? Why do people like bass controls turned all the way up? Why do people like one note horribly distorted bass boomers in their cars? But many (most) do. Many like the "sweetening" from excessive second harmonic (usually accompanied by dynamic compression). Does that make it "high fidelity"?

    Yes, Dolby/dbx are processes with complementary recording and playback. But that was my point: play them back with fidelity- i.e., output looks like input- and they sound terrible.
    permalink
    Posted 4th June 2011 at 02:30 AM by SY SY is offline
  6. Old Comment
    wintermute's Avatar
    Interesting post Pano! and a rather controversial one at that. Its rather paradoxical as well. Everything we use to decide whether something is accurate is electronic. All measurements that "prove" this accuracy are electronic (be they analogue or digital) How do we actually know that the recording and the instruments used to verify that recording are accurate? All we "know" are certain scientific principals, and we "assume" that these are all that we need to know, we can measure accuracy within the bounds of what was recorded, but how do we know that what was actually recorded is true to the original. I can see SY coming down on me like a ton of bricks any minute now

    Can of worms you are opening here, probably a good thing it is in a blog format rather than a thread Unless you are feeling game enough to start one!

    PS. I haven't done my homework yet

    Tony.
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    Posted 4th June 2011 at 01:03 PM by wintermute wintermute is offline
  7. Old Comment
    Pano's Avatar
    Yes Tony, it's a can of worms I've opened, but I wanted the worms to get out an into a few brains. Don't know if it will be controversial, as not many folks read the blogs, but at least it's a handy place to establish my POV.
    permalink
    Posted 4th June 2011 at 02:10 PM by Pano Pano is offline
  8. Old Comment
    Pano's Avatar
    @SY. Yes, there are many inaccurate enhancements that are quite popular in audio. Same in photos and video. Bad taste abounds. But let's put those aside for a moment and concentrate on music lovers and audiophiles who actually are seeking a more realistic sound, not a gimmicky sound.

    Why do they prefer the sound of what might be measured as "colored"? And let's leave aside the inaudible distortions for the moment. Why would anyone prefer an audibly distorted version and call it "more like the real thing?" It can't be all attributed to bad taste. A lot of these folks here and work with live music all day and know well what it sounds like.
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    Posted 4th June 2011 at 02:18 PM by Pano Pano is offline
  9. Old Comment
    SY's Avatar
    So what? I know a lot of first rate winemakers that drink Bud Light. And excellent chefs who use MSG.

    "Liking" something is one thing. "Accuracy" is another. You can't take a three dimensional soundfield, collapse it to two one dimensional functions (derived from a very limited sampling of the soundfield), play back from two locations in an additional acoustic space with unpredictable polar patterns, and pretend that there's anything approaching "accuracy," or that "accuracy" can be approached more closely by having an analog box of gain in the signal path that distorts. So it's down to effects people like. IMO, it's most efficacious and controllable to provide those effects with deliberate signal processing (especially in the digital domain), but others may certainly disagree. Some people just like that distortion, and it's their system, their money, their ears.
    permalink
    Posted 4th June 2011 at 07:29 PM by SY SY is offline
  10. Old Comment
    kevinkr's Avatar
    Quote:
    Originally Posted by SY View Comment
    <snip>

    Yes, Dolby/dbx are processes with complementary recording and playback. But that was my point: play them back with fidelity- i.e., output looks like input- and they sound terrible.
    Do they sound better when the complementary process is not applied? No I don't think so.. The errors are just too egregious to ignore, and I am not a fan of booming bass mobiles or of tone controls cranked up all the way either - both from an early age.

    I was thinking of more experienced/educated/prejudiced ears than you cited in your examples and ones who like me like a little (or a lot) of subtlety with our distortion.
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    Posted 4th June 2011 at 09:39 PM by kevinkr kevinkr is offline
  11. Old Comment
    Pano's Avatar
    Quote:
    Originally Posted by SY View Comment
    "Liking" something is one thing. "Accuracy" is another.
    I agree.
    Quote:
    So it's down to effects people like.
    That's were I disagree and the point of the argument. The "effects" as you call them may be perceptually closer to the original sound. There are a number of reason for that - one being human perception itself. Not a simple matter of taste, but of fact.
    permalink
    Posted 4th June 2011 at 09:48 PM by Pano Pano is offline
  12. Old Comment
    SY's Avatar
    In the sense that spiking a dish using mediocre ingredients with some MSG is "truer to the real taste of the vegetables"?

    NB: My ingredient analogy here is to the stereo process, not meaning any reflection on the quality of your components!
    permalink
    Posted 4th June 2011 at 11:02 PM by SY SY is offline
  13. Old Comment
    Pano's Avatar
    No, it's more complex than that. Sure, there is alteration that just "sounds good", I don't argue that. But there may be alteration that brings our perception closer to the real thing. I'll elaborate further after dinner. (If I'm sober enough)
    permalink
    Posted 4th June 2011 at 11:19 PM by Pano Pano is offline
  14. Old Comment
    wintermute's Avatar
    I think that this is a quite philosophical topic, and is the premise that a lot of subjectivists base their reasoning on. It is something that I think would make an interesting study.

    What I think would be an interesting experiment would be to monitor the brainwaves of multiple people listening to real live music. and then again with a recording of that exact same piece of music reproduced with different equipment. Double blind of course.

    Obviously interpretation of the data is a mine field in itself, but perhaps some insights could be gained... Thinking about it, perhaps a different recording (of the same type of music but not the piece the subjects heard) should be played back as well, in an attempt to filter out what might be brain activity relating to memory of the original event.

    Note that I have no idea if any of this is even feasible or what state the brain monitoring technology has reached. I once saw something on a medical show that was very cool, but I suspected was pure fiction, where they monitored someone dreaming and actually produced a recognisable visual of what they were seeing in their dream.

    Tony.
    permalink
    Posted 5th June 2011 at 12:04 AM by wintermute wintermute is offline
  15. Old Comment
    Pano's Avatar
    Yes, a bit philosophical. But I hope practical enough to remain grounded. Most of my premise is pure conjecture, because I have no proof, nor have I found any studies on the matter.
    Conjecture it is, but not a wild guess as it's born of many years working with live music and exposure to high end audio.
    permalink
    Posted 5th June 2011 at 12:43 PM by Pano Pano is offline
  16. Old Comment
    Remember that the recording engineer has sat and listened to the recording on similar equipment to yours, and has at his disposal the tools to add whatever distortion he wants to to improve the sound. The chances of your being able to add yet more distortion to improve the sound are slim. If you think your hearing or your listening environment needs 'correcting' in some way, I would expect that you would need something involving delay lines, FIR filters and so on and only achievable with DSP. Adding 'effects' by swapping amplifiers in and out seems like very hard work, and shooting in the dark.
    permalink
    Posted 6th June 2011 at 07:33 AM by CopperTop CopperTop is offline
  17. Old Comment
    Could we extend your argument from audio to vision?

    Could we say that the Mona Lisa is not realistic enough for our liking, and we find that viewing it through a piece of scratched glass improves it? The artist knew that he was not producing a perfect impression of a scene (2D instead of 3D, for a start) and so he introduced tricks and effects to convey his idea as realistically as possible (a bit like a recording engineer producing '3D' from stereo), but we have found that adding a piece of scratched glass that we picked up somewhere makes it more realistic. Would the same piece of glass be just as effective with a different painting, or a photograph?

    Maybe it could be argued that using a piece of intentionally ripply glass gives a 3D-like effect that is, on a very superficial level, more 'realistic' than the flat boring original. Or tinted filters on each eye gives an impression of 3D for about two minutes before the effect wears off. But long enough for us to become a devotee of that particular visual 'topology', perpetually chasing the effect again, and swearing by its wonderfulness in forums forever more.

    Are the people who advocate 'musicality' in amplifiers just the equivalent of people who "ooh" and "aah" when viewing a children's cartoon of a 3D animated fish, and who wouldn't recognise real art if it was put in front of them without a pair of special glasses?
    permalink
    Posted 6th June 2011 at 08:10 AM by CopperTop CopperTop is offline
  18. Old Comment
    Quote:
    Originally Posted by CopperTop View Comment
    Are the people who advocate 'musicality' in amplifiers just the equivalent of people who "ooh" and "aah" when viewing a children's cartoon of a 3D animated fish, and who wouldn't recognise real art if it was put in front of them without a pair of special glasses?
    I'm not suggesting that's you Pano, by the way! I realise you're just raising an interesting point for discussion. And I'm just asking the question myself.
    permalink
    Posted 6th June 2011 at 08:45 AM by CopperTop CopperTop is offline
  19. Old Comment
    OK I just looked briefly at 'The Globe Effect' (I missed that part of your post!). My answer to that very interesting observation would be that the recording engineer has, in effect, 'viewed' the recording through similar 'binoculars' to ours, and already applied distortion to correct the image we will see. We may feel the need to add a small amount of fine tuning to that correction, but there is no reason to suggest that the distortion we inadvertently get from our own viewing equipment bears any resemblance to the necessary correction. (In days gone by, the recording engineer used a specially constructed optical system of high precision lenses, but now uses a computer-generated hologram that provides a mathematically perfect compensating function.)

    We turned our nose up at $100 binoculars and opted, instead, for a pair of children's toy binoculars housed in an oxygen-free platinum enclosure sitting on spikes on a two ton granite plinth. They cost $10,000. We like the trippy coloured fringes they produce even when viewing the image of a turd.
    permalink
    Posted 6th June 2011 at 09:36 AM by CopperTop CopperTop is offline
  20. Old Comment
    Pano's Avatar
    Hey C.T. Thanks for posting. I understand your arguments and have already thought a lot about them. Glad that you went to read up on Globe Effect.

    Yes, the mastering engineer can and should have a hand in correcting the signal before it gets to us, that's his job and most are pretty good at it. But he's doing it for a vast audience who listen on everything from a clock radio, to the car, to bookshelf speakers. If the master is for SACD or deluxe vinyl, then he may actually have high end users mind. But we never know. My point is that all that may be moot. I'll try to expand further, later.

    And please don't think I'm talking about just throwing distortion of EQ indiscriminately at the audio, it needs a much more subtle and studied approach than that.
    permalink
    Posted 6th June 2011 at 02:22 PM by Pano Pano is offline
 

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