Acrylic turntable mat - snake oil or black magic ?

edited February 2011 in Analogue

Spotted this acrylic mat on ebay. Has anyone tried it or heard of it ?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120681633215&ssPageName=STRK:MEWAX:IT

Comments

  • Never heard it Mervyn.  But, big BUT, I do know that mats make a large difference.  You need to be able to adjust arm height so as not to confuse matters by hearing the VTA change as well.  I have tried all sorts of things on my 401: LP12 felt mat, cork, thick rubber, thin rubber, glass etc etc. 

    What I prefer is the Ringmat especially with the recent addition of the Ringmat insert which goes over the spindle and supports the label area better.
  • That looks like good value.  I use an SRM acrylic mat, and like it very much, on a Kenwood KD-770D.  These things are very much a matter of taste, but to my ears acrylic imparts a nice open, dynamic feel to the music.  I had to stick the SRM mat to the platter before I liked it, though, so do try this too.
  • edited February 2011
    Agree with Jim, mats can make a big difference.
    What you prefer depends hugely on the design of the TT and your own preference.
    All are a compromise (aint that the story of hi-fi...) so just a case of experimenting until you find something you like.

    Having said that, there do seem to be a few basic rules.
    Lively platters - particularly one piece castings will usually benefit from something that applies damping. For example, felt directly onto such a platter is seldom good.

    All soft rubber mats seem to impart a dark and damped quality to reproduction. Again, fine if that suits but it seems a common result from these mats.
  • Interested to learn that mats are important. I know the hard rubber one on my PL-71 (along with the arm ) is an important part of the whole deck's synergy.

    For £25 it is probably worth a punt ( for use on forthcoming 401). If it does'nt work could probably convert it to a frisbee using a hairdryer !

  • Agree Rob.  Although I've found that damping usually ends up sounding worse that what it purports to take away.
  • My Linn dealer showed me an improvement with a standard mat what i thought at the time was absolute bollox.
    All he did was play a well known track from one of my LP's then he turned the mat over and played it again.
    The difference was very surprising - Concluding that there seems to be a "right" side of a standard felt linn mat.
    as i said i would not have believed it unless i had seen it with my own eyes.
  • What Scotty said +1.

     

  • Good to see you posting here Stu
  • Right and a wrong side to a Felt met, well seeing as it's an amorphous material- probably not. 

    But does taking a record off and putting it back one again mean it is coupled to the spindle differently and might be compressing the mat differently- surely does.,
  • The only way to find out is to try it yourself
  • edited March 2011

    What Scotty said +1 .

    If you cant hear the diff between the two sides? you are Deaf OR YOUR SYSTEM IS LETTING YOU DOWN.or both.

  • Interested to learn that mats are important. I know the hard rubber one on my PL-71 (along with the arm ) is an important part of the whole deck's synergy.

    For £25 it is probably worth a punt ( for use on forthcoming 401). If it does'nt work could probably convert it to a frisbee using a hairdryer !

    The deck synergy thing is really important. The suspension system, or not, as well as the platter material pretty much determine what you need.

    I have tried others on my LP12 but none have beaten the standard felt mat. To quote a friend 'it sounds best because it's mostly air that supports the record'; I kind of understand it!

  • PACPAC
    edited April 2011
    There's an important consideration when thinking about mats, and the type of mat best suited to your TT will depend upon the platter you use.  Putting an acrylic mat on an alloy platter will give rise to different hamonic (or resonant) frequencies than the same mat placed onto an MDF platter, so no one type can accurately be said to give an improvement.  Anyone selling these making such claims must be treated with suspicion. 

    Michell's philosophy for example is that the platter material should resemble as closely as possible the damping and resonant qualities of the record itself, which is why they use a graphite impregnated silica compound, so that when the LP is clamped, the platter and LP act "as one" material resonantly. This it's claimed gives a clean sound without additional unwanted harmonics caused by resonance inducing tracking errors.

    I would never recommend an Acrylic mat for an alloy platter, you're better off by far using a good quality rubber mat.  They may be ok for MDF or other less dense materials and benefit is only gained if the LP is clamped.  Other than this, there are modern rubberised composite materials available very inexpensively which do the job just as well. 
  • edited June 2011
    hi guys,
    hope you dont mind me butting in on this discussion,
    on light alloy platters leather can be a real sonic life saver, as said its all personal preference but a bit of 'soft' leather can be had quite cheaply and it has a wonderful calming and cleaning effect on the spurious nasties that can muddy the sound, on an old trio 1033 or pioneer pl12d for instance its as if someone just snuck in and fitted a nicer cart, not so good on an acrylic platter though,
    all the best,
    matt
  • I hadn't heard of a leather mat before!
  • hi guys,
    hope you dont mind me butting in on this discussion,
    on light alloy platters leather can be a real sonic life saver, as said its all personal preference but a bit of 'soft' leather can be had quite cheaply and it has a wonderful calming and cleaning effect on the spurious nasties that can muddy the sound, on an old trio 1033 or pioneer pl12d for instance its as if someone just snuck in and fitted a nicer cart, not so good on an acrylic platter though,
    all the best,
    matt
    Never worry about butting in here. If you're nice, we won't scream at you ;-)
  • edited June 2011
    I hadn't heard of a leather mat before!
    Nor here. But what do I know about TTs?
  • hi again,
    nice friendly little forum, glad to be a part of it, i am no expert but i do love to listen to music and am more than happy to share my experiences and finding with others.
    all the old gramaphones had leather mats on ,
    leather can be a worth while addition, as ever it all depends on the sound a system has, if you are getting a shouty ,glaring or smeared mid and treble with a muddled bass it can be a god send, likewise if you have an overly smooth sound thats lacking detail with too much upper bass its a real nono, in this instance i would suggest acrylic or foamed pvc,
    as with everything in 'hi fi' its all about getting and keeping the balance of properties one finds most attractive,
    all the best,
    matt

  • I guess so Matt, interesting points.

    Is changing platter mat materials analogous to changing interconnects in order to 'tame' a characteristic or add a property to a system? Like silver verses copper et al?

    I can understand a mechanical interface like that between the record & the mat would make tangible differences a lot more easily than I can understand isolation support & different feet under solid state gear does though - yet lots of people tell me that makes a difference too.
  • hi Alan,
    indeed i believe its so, i have encountered so many enthusiasts that swear blind that if they cant measure it, it doesn't and cannot exist, yet through my years of listening to music through mostly cheap equipment i have found things such as cable , materials , isolation and support structures can all make rather large differences to the sound,not always improvements mind you!!
     the hard bit i find is picking the correct combination of all those variables to end up with a system that stops you thinking about that system and leaves you with one simple end product, that is of course the desire ,nae craving to be sat listening to music via that system ,
    as to solid state and what supports it , its strange but IME a very real phenomenon , to me at least it just extends credibility to what seems to be the fact that is ,we dont have full knowledge of what is actually going with all this equipment and how something not in the signal path can vary things,
    here is a strange thing i tried, i listened to a couple of lps via my system with headphones, all equipment was on a basic chip board unit, i then put all the equipment on granite and listened again to those same lps via headphones, the sound had changed most noticeably , i cant even begin to explain why this could be, it certainly wasn't isolation from speaker borne vibration.
    if you can be bothered or even are just curious, experiment,especially if its cheap or even free to do, you never know what you may discover,just dont do anything you cant undo.
    all the best,
    matt
  • Nice post Matt, thanks for sharing your experiences.
  • Matt, the difference you heard were the 'sinking' of vibrations from the deck through different materials. We might not be able to see it, but it's well understood and measurable. The chance of it making a difference with your amps, unless valve amps, is highly improbable.

    If you can slap your amps with the volume turned on and nothing happens through the speakers then supports won't change how it sounds- how could it?
  • hi,sq225017
    the TT was on a wall shelf screwed 7" into the brick , the amp,tuner and dac were all that was placed on the granite platforms,, all i can offer up here is , if i can hear it then its different, unless you can provide concrete proof that i am hearing things that are not there? my mate had a stack of marble, he asked me if he should use it under his amp etc, i told him to try it and see what he thought, after having it then removing the marble he keeps it under his equipment claiming he likes the way it changes the sound.
    my fav analogy on such occasions is, i had heard respected scientists saying that a bumble bee shouldn't be able to fly , they finally found out how a bumble bee could fly in 2005, so until 2005 bumble bees flew by magic!
    as i have mentioned elsewhere on this forum, there is more going on with electronics than we (and the manufacturers )currently understand fully, if we did we would all be using the same generic and perfect system, 
    here is a strange one for you, i decorated my listening room a few years ago, well painted it, i used satin emulsion, then put everything back in the same place ,same furnishings etc, just the paint had changed, system sounded different!! odd i thought, perhaps the system just needed to settle back in, but no, so after a few weeks i realized that the old paint was matte emulsion, i thought NO WAY can paint have an effect on the sound, but it was the only variable, so i re-did the paint with matte finish and sure enough the sound was as i remember it, psychoacoustics ? maybe , i am learning all the time that sometimes we need to unlearn what we thought we knew as truth in order to make way for a new truth,
    all the best
    matt



  • by the way , if anyone is using a rubber or felt mat and is wondering if a different mat can make a difference i could loan you my grubby but fine old funk acromat off my systemdek ,its 5mm thick so you will need VTA adjustment,i wont be able to send it until the end of june though, all i ask is you send it back after a month or so,
    pm me,

    :)
  • Matt, I'm the marketing director of a decent size U.S company, biasing customers interaction with product is my stock in trade. I specialize in the application of psychology, language, colour theory and a whole host of other manipulated variables to achieve the favourable outcome. Changing the colour of your room could easily affect mood; Bose ran a great sales thing back in the 80's where they biased towards their higher priced speakers by ensuring they always had red grills on them while others had less vibrant colours. They had good research to show this worked for them, for the same reason red is the most popular car colour- no doubt.

    The difference between matt and satin paint however made no difference from a physical acoustical point of view, your room would have measured identically.

    You don't mention what the amp, tuner or dac were, if they were solid state they shouldn't have been affected by what they sit on. 'Shouldn't' is a big word though, they could have design flaws that rendered them susceptible to different supports. 

    You really can't beat the slap test. If hitting your kit with your hand and imparting a huge shockwave into every part of it cannot excite an audible response how can the tiny self generated vibrations possibly be the cause of the difference you think you hear. To prove causality you first have to isolate that there is a difference. Saying you think you hear a difference isn't the same as proving a difference actually exists, for that you'd need to measure it, or beat the %'s on a test when other sources of potential user bias have been removed.

    I'm certainly not saying that without a 'test' everything we think we hear can't exist, but for me it has to start with test or measurement unless it is a gross difference, and I seldom hear gross differences. Turntable isolation and mats would be one of those rare times when I do. My records are supported on my SME10 by a 12 x 3mm carbon fibre mat which lifts it clear of the entire platter, I'm not averse to tweaks.
  • re science of aerodynamics, actually they still don't know if a plane flies because the wings are pushed up by positive pressure or sucked up by negative pressure, the dumbasses.  ;-)
  • edited June 2011
    Matt, I'm the marketing director of a decent size U.S company, biasing customers interaction with product is my stock in trade. I specialize in the application of psychology, language, colour theory and a whole host of other manipulated variables to achieve the favourable outcome. Changing the colour of your room could easily affect mood; Bose ran a great sales thing back in the 80's where they biased towards their higher priced speakers by ensuring they always had red grills on them while others had less vibrant colours. They had good research to show this worked for them, for the same reason red is the most popular car colour- no doubt.

    The difference between matt and satin paint however made no difference from a physical acoustical point of view, your room would have measured identically.

    You don't mention what the amp, tuner or dac were, if they were solid state they shouldn't have been affected by what they sit on. 'Shouldn't' is a big word though, they could have design flaws that rendered them susceptible to different supports. 

    You really can't beat the slap test. If hitting your kit with your hand and imparting a huge shockwave into every part of it cannot excite an audible response how can the tiny self generated vibrations possibly be the cause of the difference you think you hear. To prove causality you first have to isolate that there is a difference. Saying you think you hear a difference isn't the same as proving a difference actually exists, for that you'd need to measure it, or beat the %'s on a test when other sources of potential user bias have been removed.

    I'm certainly not saying that without a 'test' everything we think we hear can't exist, but for me it has to start with test or measurement unless it is a gross difference, and I seldom hear gross differences. Turntable isolation and mats would be one of those rare times when I do. My records are supported on my SME10 by a 12 x 3mm carbon fibre mat which lifts it clear of the entire platter, I'm not averse to tweaks.
    i can appreciate where you are coming from , and i cant prove anything, the paint thing really has me flummoxed! i do know that at this moment in time the granite stays under my components as when ever i remove it i do notice the difference, although i dont like granite under my turntables! go figure
    perhaps all those electronic and electrical components sing (oscillate) when a music signal is passing through them and its this being effected that brings the change i perceive ? or maybe it is all in my head ,which just happens to be the same place i process all my senses and am able to discern the wonderful thing that is music,
    i do remember a bose test that was being done at a store in Edinburgh, i walked out laughing and went and bought some B&W's
    ,i think i understand what you are getting at here is psychology of buying habits ?, something i dont subscribe to at all, i am the marketing mans nightmare,
     in this instance can we really put what i perceive as a difference down to my mind seeing something in my system has changed and then adding that to all the input my brain is getting and using to give me this thing that we call music in a particular way ,and that when i remove that visual stimuli my brain gives me a different interpretation of said music , even when i am laying with my eyes closed but know its not there ? perhaps!
     its an intriguing business for sure and just adds to the complexity of it all.
    all the best,
    matt


  • re science of aerodynamics, actually they still don't know if a plane flies because the wings are pushed up by positive pressure or sucked up by negative pressure, the dumbasses.  ;-)

    :-))
  • Mattlynch,

    just in case you think you are going mad I thought I would share some experiences with you re isolation and sonic performance. I have observed and have demonstrated to a number of folks, some 'educated' in the world of audio and others who are not so educated, the effects of vibration isolation of devices. I would say that it would be pretty well agreed that isolation would create significantly audible effects with tube gear so I shall leave that as a given and concentrate on ss equipment instead. I agree with Simon that in theory ss equipment should show no diff in performance with or without isolation. Very interesting that my shared experimentation with quite a number of others has shown quite clear Improvement in sonic performance with all ss equipment when placed on an isolation platform. This has been done With power amps and dacs as well as cd transports.

    Firstly considering a Transport:
    The comparison done here was a concrete slab floor of a workshop (at least a 4 inch slab direct on the dirt or possibly 6 inch) compared with a damped platform sitting on springs which were sitting on the same slab floor calibrated to a given frequency for the mass they were supporting. Both pretty solid one would think. And yet experimentation with just such a test with 5 folks present who have about 100 yrs combined experience in the audio/audio electronics game showed an improvement with the isolation that had several of them laughing and shaking their heads in amazement. The improvements are typically in the areas of imaging, sound staging (all aspects of) and reduction of glare, brittleness and stridency (particularly on violins).

    A similar comparison was then done sitting $20k worth of ss mono block amps on slab and on isolation platforms. Same type of improvement but to a lesser degree. Still a blindingly obvious improvement. if you give the amps a whack as Simon suggests I betcha would hear nothing. So why the improvement? Dunno frankly. Perhaps mechanical resonances in ps caps????

    Then on several different occasions have done a similar comparison with a tda1543 based ss dac with several observers commenting on the improvements when put on an isolation platform. Done blind as well as sighted. Easily repeatable tests too. I tend to do this to demonstrate to those who have not experienced such phenomenon. It can be an eye opening experience.

    Perhaps the only conclusion that I can validly extrapolate is that all of the ss equipment that I have been exposed to (pretty decent amount!) is faulty in some way?

    So I very much concur with your thoughts that there are potentially many factors affecting audio reproduction that we do not yet fully understand. I suggest that there are many things in the world around us that we do not yet fully understand. Makes it a fun place to live don't you think?

    cheers

    Rawls
  • Hi Rawls,

    can I quickly thank you for making such an interesting post in a thoroughly reasonable way. I have to agree with your sentiment re gear seeming to respond to isolation when one might think it shouldn't. I haven't been able to consistently demonstrate this at home though I have been struck by it before.

    Do you have any photos of the isolation platform you used? I am genuinely curious but I'm having trouble visualising a calibrated stand with springs, unless it is a TT type stand. How would it be calibrated?
  • hi guys,
    nice post Rawls,
    its always good when others get similar findings to me, confirms i am not going quite as mad as i thought!
    i feel that manufacturers wont see the devices as faulty, more a case that if they cant measure it it doesn't matter, even if they could i wonder what could be done about it , they are limited by the components they have available and these components are all susceptible to vibration from external sources and from self vibration that occurs when the audio signal is passed through them and this i believe is what we are attenuation when we use isolation platforms etc , the first time i became aware of components 'singing' was from an old trio ka3700 amp i had , with no speakers or headphones attached if i put my ear very close to it when music was being fed into it i could hear music emulating from the amps circuit!! this made me conscious of the fact that we are dealing with more than just external vibration ,, the best thing i have tried under my amps is an atacama se24 speaker stand filled with sand and lead shot which i think may act as a drain or sink , it certainly does something positive to the sound .
    i too would love to see a pic or two of the isolation you used,
    all the best for now,
    matt

  • Alan

    Thank you for your comments. To answer your question initially visualize a platform sitting on top of 3 springs placed in a triangular fashion. On top of this platform is then placed the amplifier. The springs are wound with a rate to give a certain optimized frequency of the resultant natural oscillation in the vertical axis. This is what I meant by 'calibrated'. The spring constant is selected for the specific component/platform mass combination. The platform itself is a constrained layer style lamination of several materials to give mass,rigidity, and very high self-damping so that the platform acts to sink vibration away from the component. The whole assembly is then rather effectively isolated from the floor/slab so that floor borne vibration ( quite significant amounts of it seem to exist from speaker energy coupled into the floor as well as other sources) is not coupled back up into the platform/ component. If you have a look at the HRS racking system it is I feel, conceptually similar but ours is done using 'calibrated' springs on 3 adjustable points rather than the rubber pucks that HRS use. The concept of coupling components to racks which are spike-coupled to the floor to, in theory, drain vibration to the floor has one minor flaw. Our experience/experimentation has shown that every floor that we have ever used is quite 'alive' with vibration which couples back into the devices with negative consequences.

    Mattlynch,

    Sorry Sire, my comment about the 'only conclusion I can draw' etc was meant very tongue-in-cheek. My experience is that all components (ss,tube etc) are susceptible to sonic degradation from vibration. If you ever have a speaker crossover connected externally, have a close listen to the inductors (assuming they are decent ones and are air cored). They make awesome little speakers!!!!
    I very much believe what you say about those stands under your amps. Conceptually the same as our isolation/damping platforms. I am soon to embark on a project of building a 4-bay version of this rack system which I shall post some photos of when it is done. Sadly I cannot afford the $80 -$100k or so to purchase the HRS equivalent of what I am building. Such is life as a pauper.

    cheers

    Rawl
  • I'd be very tempted to record the output into a decent digital recorder and then try and null the isolated and none isolated samples. In fact without trying this or performing some sort of effort to remove all other potential forms of bias it's not really much more than  a nice anecdote.

    Do come back and tell us how you get on.

    Regarding inductors signing along, it's well known that they can if not wound tightly, glued, or tied down sufficiently or if they aren't varnished/potted they are just electromagnet coils after all.  I've never seen any proof that the vibrations they pick up inside speaker or otherwise are sufficient to impose any 'audible' distortion on the signal they pass. Would seem easy to prove , especially if you were selling quality in speakers.
  • edited July 2011
    I'd be very tempted to record the output into a decent digital recorder and then try and null the isolated and none isolated samples. In fact without trying this or performing some sort of effort to remove all other potential forms of bias it's not really much more than  a nice anecdote.

    Do come back and tell us how you get on.

    Regarding inductors signing along, it's well known that they can if not wound tightly, glued, or tied down sufficiently or if they aren't varnished/potted they are just electromagnet coils after all.  I've never seen any proof that the vibrations they pick up inside speaker or otherwise are sufficient to impose any 'audible' distortion on the signal they pass. Would seem easy to prove , especially if you were selling quality in speakers.
    hi , indeed it would be great if someone with appropriate equipment that its self was 'guaranteed to not affect the results' ,were to take on the experiment , never done such a test myself and wouldnt know how to , i do though wonder if i did do such a test and found a nul result then went back to my system and was still aware of the difference i get what i could conclude from the test, was the test faulty? is something in my system changing when i place the device on the different support? etc ,
    as i have written before on this forum and others , i will leave the hygienic testing to those in the know and who have time and expertise enough to do such things, myself, i will just use my system and employ the little tweaks that have proven themselves over many years to be beneficial when it comes to enjoying my small music collection, if i could i would set up my system to cosmetically blend in with my listening room i would but the sad truth is that when i do it impacts the reproduced sound quality and since i cant afford to build a new system that would work in the cosmetically better position, i feel compelled to choose the ugly but better functioning layout .

     i do course understand the many variables that may also be in effect but when i try two different supports in the same position on the same concrete floor with all cables running in exactly the same way and still hear the difference would the recorded test change that,? , cant say as i haven't tried but ,i suspect not..
    best regs,
    matt

    :)
  • I'd be very tempted to record the output into a decent digital recorder and then try and null the isolated and none isolated samples. In fact without trying this or performing some sort of effort to remove all other potential forms of bias it's not really much more than  a nice anecdote.

    Do come back and tell us how you get on.

    Regarding inductors signing along, it's well known that they can if not wound tightly, glued, or tied down sufficiently or if they aren't varnished/potted they are just electromagnet coils after all.  I've never seen any proof that the vibrations they pick up inside speaker or otherwise are sufficient to impose any 'audible' distortion on the signal they pass. Would seem easy to prove , especially if you were selling quality in speakers.



    Simon,

    As you seem to be the one that claims that something is non-existent unless it can be measured would you be so kind as to tell me what 'decent' a/d device I should use that is guaranteed to be more sonically and musically resolving than my system. If you would be so kind I shall see if i can source such a device and record the comparative outputs if would you also be so kind as to advise exactly where I should record said signal from.
    Of course, to ensure that the device imposes no degradation it would have to include an equally resolving and transparent d/a stage so that I may compare, thru listening comparison, the original analog o/p of the transport/dac combo with the analog playback of the a/d plus d/a output of the recording/test device.
    If I cannot pick the difference then it will be a god device to test with.
    Or would you suggest that I use the a/d recorded signal and burn that to cd and then play it back thru my transport?

    If such a device exists please enlighten me because I will use it to replace my curent tube output dac.

    As far as nice anecdotes go, 5 guys with 80-100 yrs combined experience in audio, equipment design/modification, electronics, speaker design etc obviously wouldn't have a clue as to whether something sounded different with/without isolation. One obviously has to rely on the measurements made by a 'decent' digital recorder to assess whether a difference occurs. Some people listen, some people have to measure. I personally listen because I find the end results are better.

    I have no intention with regards "do come back and tell us how you get on" unless you specifically define the equipment to be used and the precise methodology to be followed. I and other colleagues have done testing in the past as demanded by the "measurement" brigade only to have the methodology consistently criticized. Not so this time.

    Looking forward to your suggestions,

    Cheers

    Rawl

  • edited July 2011
    hi again guys,

    Rawl puts up a good point here that the sceptics must start to bring forth evidence including the exact conditions they were performed in right down to the fibre mix in any rugs carpets etc construction of furnishings, wall paper or paint etc etc and you are starting to get the picture, all too often i read the same 'nice anecdote' comment and how we should 'record and perform nulling tests' and as yet i haven't seen any of the sceptics actually provide evidence  in the form of results from those 'easy to perform' (ahem) tests,, in actuality all the sceptics comments just seem to be those very anecdotal comments they profess to be trying to get past  , recording digitally is one thing but does that actually bring forth a definite result that will transfer to you the listener when you are sat at home in front of your system ? the truth , as painful as it is for some to read , is that those tests dont matter , the only test any domestic hi fi music fan can employ is to try things and gauge the sound over time , even if there are psycho acoustic effects biasing the results if those effects stay and are consistent over a prolonged period then i would venture to say that they are worth having if they enhance the listening experience,

    to be inquisitive is a good thing as it brought us all the wonderful thing that is home reproduction of recorded music but, if you are one of those sceptical and inquisitive people then i would like to read your findings rather than your same tired old anecdotal responses , i dont mean this in an aggressive or confrontational way , i would just like you to provide the absolute definitive evidence you claim is so easy to come by , many thousands have tried and have all reached the same result, they all go home to their systems and find an infinite number of variables that stop them getting the same results as the test and thus the test becomes the problem and something of a waste of time.

    perhaps its time someone started a forum dedicated to audio sceptics where they could all hang out and suggest various tests for each other to perform but not actually do the tests themselves , that should move home audio reproduction forward in leaps and bounds, (kidding fellas!!)

    all the best,

    matt

    :D
  • You don't need an A/D Rawl, just a coil and an oscilloscope. Zip tie the coil to you test bench, pass a steady state signal through it then do the same withs speaker pointed at it and see if there's any difference on your scope.

    Matt the burden of proof is usually on those making the claim. Of course that doesn't suit people peddling myths and Foo.
  • i think you may have missed the point i was making, your suggested test with a coil on a bench may well give no measured difference on the scope , but would seem to me at least to have no comparison with listening to music via a hi fi system , to test the system fairly we would surely have to measure the output of that whole system using the very finest mics and A/D converters under perfect anechoic conditions with and without the questionable changes and using music, or do many thousands of tests with those great mics etc in the homes of those many system owners that claim to be getting differences in performance , the thing about all this testing is that we would be hunting for measured differences that may not be detectable by even those finest of mics etc , and if those tests bring no measured difference could that be considered definitive and absolute? as a listener if i was shown these tests and was agreed that no measured change was detected and then go home to my system and find that i can still hear the difference i would still only be able to say "i can still hear the difference and so would keep using it as i have for many years", only that end result is what actually matters because i bought the system to sit at home and listen to and enjoy music ,as far as i am concerned the proof is already in full and conclusive evidence, i hear the evidence everyday . that is a far better test than looking at a scope measuring a coil on a bench as a comparison of how my system sounds how it does, but as i have said before , its only hi fi , do with it as you choose.

    all the best,

    matt

    :-)
  • Matt, if it doesn't show up on a scope that can measure a 1/10,000 of a volt it is impossible for it to be audible as no speaker on earth is sensitive enough to react to such a small voltage.

    It's not a matter of opinion, it's a simple provable fact. If you could get it to show somewhere between 100-1000th of  a volt then maybe, just maybe it might be audible.

    There's no magic in listening to music, a voltage/distortion is either large enough to move the driver or it isn't, and if it doesn't show up on a scope then it isn't, no way no how. 


  • hi again,

    indeed i cannot argue with that but,as i said ,if the test cant show up a difference but the listener does still find a difference in the sound over many years of listening we can with confidence conclude that either there are psychoacoustic effects that regardless of cause make the perceived sound better,

    or ,

    there is something going on that is not as yet understood and is beyond the readout of voltage fluctuation on an oscilloscope ,



    if its the former should we stop using that device and try and convince ourselves that it was making no difference and the sound quality hasn't lost something we found we liked ?

    if its the later then we must accept we do not fully understand how each resistor ,capacitor ,diode ,dac chip, op amp etc within a component is interacting with whole system as a device in a very polluted environment while being fed a rather complex musical signal, and this leaves me more sceptical of the tests than of my findings of actually listening to music via my system and gauging that end product as definitive for me, since i live with the system i dont think thats an unreasonable stand point.

    i am not saying for one minute that the tests dont ever bare fruit, what i am saying is that to consider such electrical tests as definitive is like reading a book when only  the first chapter has been written and assuming that we know how its going to end. even very experienced hi fi designers and manufacturers will tell you that.

    thats just my view though and you are absolutely entitled to yours as that coil didn't show any change in voltage and so we now know that a coil will not change voltage being fed through it when a loudspeaker is playing music near it,

    all the best,



    matt



    :-)
  • I  think that I must be missing something here.  How did we get from a component being affected by mechanical vibration to a coil on a bench being affected by a speaker playing within some proximity.  Not too sure how these quite relate.  I was talking about components being affected by mechanical vibration (floor borne POTENTIALLY caused by speaker induced vibration coupled into the floor or air-borne through air pressure effects) and we get to a coil strapped onto a bench???????
    I really don't care too much about whether we can measure the effects of this setup or not.  It bears no relevance whatsoever.

    This thread is going in the same direction as the 'dc power cables'. Ie downhill.  When asked to define the testing methodology to be followed the answer is to go on some red-herring tangent and ignore the question.
    Simon, I wholly concur that the onus of proof is on the one making the claim; however, if another party is Demanding proof then the definition of methodology is on them.  To clarify let me give an analogy.
    Lets say that I have a new drug that I claim can cure cancer.  I go the the FDA, TGA or whatever regulatory body and they demand proof.  So I ask what proof and they reply that I need to prove that it works.  "And how do I need to do that to satisfy you"asks I.  "We need proof" they respond.
    "So how do I perform such testing that you will accept the results" asks I.
    "We demand proof" they respond again.
    And so I go and define my OWN test and take the results to them and they say, "no this 'proof' is not acceptable, we think the test is flawed". Etc etc etc etc etc etc etc..........
    I think most people will understand this analogy.  
    The one demanding the proof is responsible for defining the exact test procedure to be followed.  I kinda think that is what I asked for.


    Simon said: "I'd be very tempted to record the output into a decent digital recorder and then try and null the isolated and none isolated samples. In fact without trying this or performing some sort of effort to remove all other potential forms of bias it's not really much more than  a nice anecdote."

    So it is not ok for me to require the testing of the 'insertion loss'/resolution  of the recording system by doing a d/a of the a/d via listening test, blind if you like?  Is this not removing another potential form of bias, ie testing whether the 'decent digital recorder"  has resolution/performance greater than the system being tested.    If it does not pass this test then the whole process becomes null and void.     Of course the d/a would have to be of the same performance level as the 'decent digital recorder' to not influence the test.


    Simon said: "Regarding inductors signing along, it's well known that they can if not wound tightly, glued, or tied down sufficiently or if they aren't varnished/potted they are just electromagnet coils after all.  I've never seen any proof that the vibrations they pick up inside speaker or otherwise are sufficient to impose any 'audible' distortion on the signal they pass. Would seem easy to prove , especially if you were selling quality in speakers."

    Simon, would you please show me where I suggested that the vibration that inductors may pick up "inside speaker or otherwise  are sufficient to impose any 'audible' distortion on the signal they pass."  I am a little at a loss as to where I suggested that.
    And on a tangent, what if the inductors are varnish impregnated and they still sing along?


    I shall patiently await the definition of the process and equipment to be used to definitively prove that vibration isolation does/does not make any difference.  Just as a little food for thought is not a commonly used oscillator that acts as a a reference device in the digital world an electro- mechanical device that just may be a little sensitive to vibration?

    In the meantime I shall just 'do a Matt' and trust what I hear.

    Cheers

    Rawl
  • It's this simple, if you can do it with your eyes shut it's a real effect and if you can't it isn't....
  • Years ago I took off the felt mat - and put an album on an album to play it - not ideal as the surfaces were not truly flat against each other - but it convinced me it was the best way to go.  The Systemdek IV had a sandwich platter with a quarter inch acrylic/vinyl topping.

    If you are worried about dust or grit (if you use a clamp with an acrylic platter or platter mat) go to the Army and Navy or a material store and buy stiff interfacing material (comes in White or Black) and make a dust mat from it (it is extremely thin).  
Sign In or Register to comment.