Any Engineers On The Forum?

Discussion in 'General Science & Technology' started by Dr Mabuse, Mar 27, 2010.

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  1. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

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    Lemme get an informed take on this pitch:

    A person claims that the spinning of a DVD/CD spindle causes "micro vibrations" than cause visual glare, audio and video distortions, loss of depth of sound, all manner of things because the micro vibrations affect capacitors, op-amps, and other sensitive parts in the digital to analog conversion.

    So by putting an adhesive disc on every one of your CD/DVD disc, that 'absorbs' these vibrations, you will see "cleaner performance (sound), better bass, more detail, greater clarity, better highs and midrange, more natural sound, better imaging, better soundstage, better video, richer colors, and a greater depth to the performance." All from using these adhesive foam discs on every one of your CDs and DVDs.

    Are there any people with the education and experience to actually address(intelligently) 'micro-vibrations' and their possible effects on capacitors and the like in home electronics that would result in loss of audio/video quality?

    Please, if you can't address the question directly, would you keep your opinions out of this thread? 'Sounds like nonsense' and other statements of the obvious are really superfluous and not needed. I'm wondering if an actual engineer might have factual knowledge about capacitors and other electronic components as to small vibrations.
     
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  3. oozish Banned Banned

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    thou, the heat is the issue that matters for cd's more than microvibrations.
     
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  5. Stoniphi obscurely fossiliferous Valued Senior Member

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    Capacitors and other such electronic devices store, modify and manipulate electric energy. Vibrations (on any scale) are mechanical energy and do not directly interact with electronic devices save in a gross physical manner - such as smashing the capacitor so that it fails, vibrating a loose connection off its contact point or similar interactions.

    In order to directly affect an electronic device in the manner that you describe, it would be necessary to convert the mechanical vibrations into an electric flow, this via a piezoelectric - electric converter, usually based on a slice of a quartz crystal, like an old crystal radio receiver.

    The thing with digital signals is that they tend to either be there or be lost. Surface scatter of the incident laser light from the cd or dvd surface would destroy the signal completely rather than distort it as in an analogue device.
     
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  7. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

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    Well we started using multiple lasers more than a decade ago to compensate for the optical stuff.

    If any of you are old enough to remember, the first car CD players skipped if a gnat hit the windshield. Today with multiple lasers, far more advanced signal processing, and tighter spindle speeds you can go off-roading and not experience skipping with many players.

    But I'm wondering if any electrical engineers, or maybe materials people on this board could give a detailed explanation about the 'micro vibrations' and circuitry in a consumer electronics device like a DVD/CD player.
     
  8. Stoniphi obscurely fossiliferous Valued Senior Member

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    What is there to explain?

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  9. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

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    So you are an engineer, and you have direct knowledge, not an assumption, that micro-vibrations have no effects whatsoever on a circuit board doing the processing in a CD/DVD player that would reduce image and sound quality.

    In case you didn't know, 'audiophiles' have been paying fairly considerable sums for vibration reducing mats to set components on, rubber feet for the legs of such devices, all manner of 'tweaks' to get better audio and video out of their devices by reducing vibration. What I was looking for was a more factual, if not scientific(meaning I could cite some testing, or a paper, or etc) response to one of the people hocking this kind of ware, and using 'technical sounding' language to do so on another forum.

    Now a brief mention of mechanical vs. electrical energy was made above, but that is not very detailed, and there is nothing like a citation or a reference to established knowledge on that assertion as best I can see. I would assume some actual testing has been done as decades of research, testing, and refinement have gone into consumer electronic devices. I would also suspect such testing was done in the aerospace arena extensively to understand how electronics would work in space after the rather dramatic vibrations and energies experiences during launch. Also in aviation with fighter jets and etc, for the same reasons.

    Maybe you could be a tad more verbose as to what/why you feel that information is factual an why/how you came to know that? It would help if you could.
     
  10. Stoniphi obscurely fossiliferous Valued Senior Member

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    I am somewhat familiar with several diverse areas in the arts and sciences, engineering inclusive, post graduate. I am an also an audiophile, with a dozen or so sound systems lying about. The oldest and one of the most expensive is a Phase Linear 400/Marantz 1120 preamp/Thorens turntable/Utah+EV Infinite baffle speakers (with a recent 175 W Pioneer subwoofer) that I bought brand new in 1973 - the same year that I bought my Les Paul Black and Pearl Delux Custom. Both are still quite functional, thanks.

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    I am sorry that you did not understand my brief, simple explanation of the difference between mechanical and electrical energy and their interactions. I learned what I know about this in both undergraduate and graduate university classes in a variety of mathematics, engineering and physics classes as well as in shop and lab.


    The person that you cite in your OP is not familiar with this technology. The cd spins, the laser shines on it. On the cd surface there are a bunch of little dots. The little dots are either little pits burnt there by a laser or they are flat and smooth. When the laser light hits them, they either reflect good or not. If they reflect good, a "1" is registered by the read chip, if the dot does not reflect the light a "0" is registered.

    This series of "1"'s and "0" is called a "binary string". These "binary strings" tell the chip to make a particular sound, all of the binary information on the cd put together makes the music that you hear. If there were any mechanical vibrations present, the laser would not read the pits and flats, no binary strings would be sent to the read chip so it would not generate any sounds for you to hear. The laser must reflect off the cd surface, and lasers do not 'glare' because they constitute a very narrowly focused, coherent beam of light.

    Aerospace applications require stuff like heavy solder joins, redundant systems and all of the electronics is maybe 30 years old. No cds or their ilk, sorry.

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    As for aircraft, what good would a rubber mat under a cd player be when the airplane does a barrel roll? (think gravity here)

    I will not give you citations as I do not have the time to do that leg work for you, but try Wiki for this, they can give you that stuff. IMHO, putting rubber mats under cd players is a great way for the seller to make money off the uninitiate, but will not effect the sound that you hear one little bit.

    If you have a direct question, go ahead and ask it though, try to be specific.
     
  11. superluminal I am MalcomR Valued Senior Member

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    10,876
    Ok. Here we go. Electrical engineer here with 25 yrs experience in Military, Industrial, and Biomedical test and design engineering.

    1) Microvibrations in a digital media such as a CD/DVD if not correctly designed for, will either have no effect on the digital signal (due to luck), or cause digital artifacts or complete garbage. This all happens at the read-in level, i.e. laser detectors and front end amplifiers.

    2) Modern active components (such as the processors, DACs, op amps, and comparators) are immune (in function) to even high levels of vibration encountered in military field equipment. The passive components (resistors, capacitors, inductors) involved will also be virtually immune to parameter variation even at high levels of vibration, let alone the levels encountered in a DVD/CD player.

    A production DVD/CD player that exhibits any measurable degradation in output performance due to microvibrations is a faulty product.

    Now, having said all of that, My assumptions are:

    1) That "microvibrations" are exactly that. Vibrations that are incredibly small in comparison to those we might normally encounter in everyday life, let alone extreme military or industrial applications

    2) That the device in question is a "modern" player that uses commercial grade components (which nowadays are equivalent to industrial or even military grade components of a decade ago - mainly due to production process improvements).
     
  12. superluminal I am MalcomR Valued Senior Member

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    10,876
    You are correct sir. Unless there is some new underlying principle involved in DVD/CD players that we have missed over all of these years...

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  13. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

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    Nice. This is what I was looking for. Thanks.

    The issue is this - this is basically what I already knew/suspected, but I was looking for some data to back it up. Any chance you might have an idea where to start, searching on search engines has not been successful really. Some testing done as to vibrations and circuitry related to my question? Anything of that type? I have found testing as to failures of solder points and connections and the like in military circuit boards and the like(which the other poster alluded to quite accurately). I have also found data on ceramic capacitors possibly being affected by vibration -

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    - for one example. I've also found the patents for isolating vibration on circuits boards for vibration sensitive components and the like, but nothing directly addressing the testing on the components like you mention. I just believe in trying to gather an understanding of something before I speak.

    "First learn the meaning of what you say, and then speak." - Epictetus

    To be clear, I believe both you and the other poster(tangential ramblings about CD players in space/fighter jets and other nonsense aside). I know such testing has taken place due to it being so obvious that it would required. If somehow you or the other poster had some notion I was doubting your assertions you were incorrect, and may have simply assumed it due to the normal nature of discussion on this forum or etc. I completely understand that assumption believe me, but you were off base if you were assuming such in this case.

    I just wanted something in the way of data to cite, to back up the assertions which have been made by you. If any is available. If not thanks for taking the time to post anyway, it was helpful.
     
  14. superluminal I am MalcomR Valued Senior Member

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    10,876
    I didn't misunderstand.

    This:

    makes you an enlightened individual imo.

    My experience comes from directly testing military grade electronics through sinusoidal and random vibration profiles designed to approximate the environments on many things - from aircraft carrier decks to rocket stage separation controllers. What you are looking for is usually obtained from the manufacturer of the component in question on a spec sheet (QA engineers usually have the rather unpleasant task of compiling this information and doing a fault/risk analysis (FMEA) of the design, with input from the rest of the engineering team, of course.) I don't know how you would find this information just floating around the interwebs though. Sorry.
     
  15. superluminal I am MalcomR Valued Senior Member

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    10,876
    Yes. Just checked your link. Have you ever heard "ringing" coming from an oscillator on a circuit? This could be an inductor actually having an unbound winding vibrate (say in a switching supply).
     
  16. Dr Mabuse Percipient Thaumaturgist Registered Senior Member

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    714
    Thanks again.

    I think I have the basis to make an intelligent refutation of the ridiculous claims being made by the modern 'snake oil' salesmen hawking these wares.

    Funny thing is... real 'snake oil' often had lots of strong alcohol in it, and most often laudanum, so if a user actually drank the stuff, a litany of ailments would indeed be truly relieved, and the user would get a definite payoff.

    This type of 'snake oil' pitch has only the placebo effect and no real payoff, yet it's remarkably effective nonetheless. Now as we know, men who have lost limbs, had severe/grotesque wounds from battle, etc, had their pain relieved fully and were prevented from entering shock and dying by nothing more than the placebo effect alone. So I don't underestimate the power of that. But it still surprises me such claims could fool even educated people and thereby get them to spend sometimes notable amounts of money on such 'vibration reducing' bunk for their home theatre equipment.
     
  17. superluminal I am MalcomR Valued Senior Member

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    10,876
    Well, caveat emptor, right? All you need to do think a bit though. If there really were any measurable aftermarket gain in performance to be made by these things, wouldn't DVD manufacturers long ago have exploited this miracle in their own designs to deliver significantly better performance than their competitors?

    Nope. It's 99.9987% certain to be bullshit.
     
  18. Stoniphi obscurely fossiliferous Valued Senior Member

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    3,256
    I concur.


    Hey, you’re real welcome there. Hope you get a good grade on that paper.
     
  19. Fraggle Rocker Staff Member

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    24,690
    We did this for turntables and tape decks. The effect of spurious vibration on a turntable is obvious: the needle is tracking the image of an actual sound wave in real time, so if you perturb the movement of the needle you alter the wave.

    The effect on a magnetic tape reader is only slightly more complicated: The image of the sound wave has been translated into a stream of magnetic fields which are also being read in real time. The magnetic fields are difficult to perturb, but altering the speed of the tape movement will accelerate or delay their passage under the head--usually an oscillation of both, creating vibrato in the pitch of the reproduced sound. This was common in the early amateur-installed automotive cassette players.

    Even a microphone could be affected by vibration and the early microphones were elaborately shock-mounted.

    But digital audio, video and data tape and CD readers are immune to this because they can monitor and, to a limited extent, compensate for slight fluctuations in the rate of passage of the DISCRETE bits under the head. That in a nutshell is arguably the key advantage of digital media over analog.

    But audio and video devices that process ONLY electronically coded information cannot be affected by vibration of less than traumatic scope. It's impossible to affect the travel of a stream of electrons in a wire, transistor, vacuum tube or other electronic component by physical mishandling. The electromagnetic forces that control their lightspeed movement are millions of times stronger than the kinetic forces generated by jostling, which therefore simply go unnoticed. It's comparable to a dust mote landing on one of your hairs: yes, a little extra gravity is now pulling down on that hair, but it's several orders of magnitude below your threshold of feeling the weight.

    We NEVER bothered to protect our amplifiers, tuners, preamps, equalizers, etc., from trivial impact. Car radios were never as carefully mounted as tape decks.

    Well of course some people did. They were the ones like your colleague, who did not understand electronics. There are always predatory marketers who are happy to take advantage of consumer ignorance. Just go into any store and walk down the health and diet supplements aisle.
     
  20. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    9,391
    This is a well-known scam. It's been around for decades, and is often used as a prototypical example of the sort of nonsense that laymen will spend real money on, if marketted correctly. Do not spend your money on this stuff.

    The funniest version held that if you color the edges of CDs with green market it would improve the sound.

    At the end of the day, those worried about the quality of their CD and DVD electronics should spend their money on better CD/DVD players or, in extreme cases, take a digital output from those devices to a premium quality outboard decoder.
     
  21. Nasor Valued Senior Member

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    6,231
    Sadly, one only has to look an most audiophile magazines to see all manner of utterly insane products. There's an entire speaker cable industry devoted to convincing people that their $300 super-shielded cables with gold coated connectors and magical pixies that massage the audio waveform with sensual massage techniques will deliver sound that's perceivably better than lamp electrical cord.
     
  22. quadraphonics Bloodthirsty Barbarian Valued Senior Member

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    9,391
    My personal favorite is amber tweaking. It seems that people have caught on and so the websites don't exist any more, but the premise was that chunks of amber would improve the electrical properties of audio equipment. So these companies would try to sell people expensive pieces of amber to set on top of their audio components. Hilarious!
     
  23. Nasor Valued Senior Member

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    6,231
    My favorite was setting your cables on little wooden platforms (rather than letting them rest on the floor). I don't know if anyone ever actually bought any, but there was some company advertising these magic wooden cable support platform that would keep your cables safe from the data-stealing gremlins that live on the surface of your floor. They were made from some special, uncommon wood that had special electrical properties to blah blah blah. I don't remember the price, but they were very expensive. Some magazine actually reviewed them, and claimed that they improved the sound quality

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    It's interesting that although audiophile magazines are always reviewing and comparing all sorts of products, the one sort of comparison that you will almost NEVER see is a "blind" comparison with a significant number of test listeners - even though on the face of it, this seems like the most obvious sort of test to do when comparing audio equipment. One could cynically speculate that the magazine editors don't want to burst people's bubbles by telling them that their $3000 speakers aren't actually any better than a $200 set of speakers.
     
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