Author Topic: demagnetisers  (Read 12679 times)

Gliding Dutchman

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Re: demagnetisers
« Reply #15 on: October 18, 2007, 08:44:27 AM »
I think inviting Timber is just asking for kak ;)

If you do go Timber, remember your loudhaler :D

Ag - dont worry... it is him against a whole crowd!!  ;D  ;D  ;D

Online Shonver

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Re: demagnetisers
« Reply #16 on: October 18, 2007, 09:05:15 AM »
Gents, I don't believe in pseudo-science, but I do acknowledge at least the existence of certain audiophile "party tricks" [games... nor-filties... paartie tricks....*].

A favourite party trick of a local audio retailer is to - without warning - suddenly swap the absolute polarity of the loudspeakers by reversing both cable connections. It makes a very noticeable difference though, as usual, it is difficult to say which polarity is better. And subsequent re-swapping does not make as big an impact. Now, he does not do this to prove or sell anything; he's just having fun (and he's one of the few salesmen I trust: the audio business is not his mainstay). But my point here is that we must not discard subjective observations/perceptions as nonsense simply because the science behind it is not immediately apparent, or because the person reporting said phenomenon cannot explain the science.

For instance, in an article I posted a link to elsewhere (link now dead), some engineers investigated the measurable effect that different loudspeaker cables had in an audio system. They (being engineers) were baffled that even a short piece of wire produced an effect. At the end of the day, it came down to the RF susceptibility (admittance) of the cable or, more correctly, the ability of the cable to reject RF signals in that system.

Should they have shrugged off their initial observations because it just cannot be?

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« Last Edit: October 18, 2007, 09:07:28 AM by Shonver »
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Offline DRNB

Re: demagnetisers
« Reply #17 on: October 18, 2007, 09:25:15 AM »
To de-magnatize a LP does makes sence to me, as I would expect in the process you getting rid of static charges in the process. My scepticism comes into the claim that de-magnitizing a CD also makes a "wow" difference.
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Offline Hi-Phibian

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Re: demagnetisers
« Reply #18 on: October 18, 2007, 09:29:03 AM »
Who said wow? Worthwhile yes for a head demagnetiser I already own or perhaps that Bedini for a few hundred.....Not thousands though I guess it is all relative...

Shonver, you sober? :o Alter ego typing? Just surprised you typically do not give this the tod....
« Last Edit: October 18, 2007, 09:32:31 AM by croak »
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Offline DRNB

Re: demagnetisers
« Reply #19 on: October 18, 2007, 09:44:12 AM »
Croak, it still doesn't make much sence to me to demag a CD. The unit in discussion here I believe is in the range of R15k. For that price the efect should be "WOW"  ;D ;)
« Last Edit: October 18, 2007, 10:04:48 AM by Norval »
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Online Shonver

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Re: demagnetisers
« Reply #20 on: October 18, 2007, 09:54:14 AM »
Shonver, you sober? :o Alter ego typing? Just surprised you typically do not give this the tod....

Croak, your comment is too cryptic for me to understand (sorry if I'm a bit dof this morning).

All I'm saying is: let's not discard the reported experiences of others offhand (and I mean those who are not selling, and those who have not just splashed out on said equipment).

In the example I related there was, after all, a scientific explanation...

Edit: see bold text
« Last Edit: October 18, 2007, 09:58:39 AM by Shonver »
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Offline Timber_MG

Re: demagnetisers
« Reply #21 on: October 18, 2007, 10:49:31 AM »
Will there be decent acoustics and loudspeakers on audition? If it is a case of listening to just another pair of so-so 6"/1" configured loudspeakers and acoustics like one might expect then I am not all that tickled.

@Shean: Expectation effects are exascerbated in groups, an effect used to great effect by charismatic religious movements amongst many others. While I find the marketing aspects and social dynamics interresting, I doubt that I would venture out to listen to such a set-up. I also used to believe that cables have at least some effect, but a truly blind swap made all this perceived difference simply disappear.

If the person doing the actual change under knowledge of what the path selection is in an A/B test then it is invalid as their reaction or the fact that they're making a change known to the audience raises expectation.

Offline joel

Re: demagnetisers
« Reply #22 on: October 18, 2007, 10:58:28 AM »
I wasn't speaking about any model, but the concept in general.

Have I heard/seen differences after de-magging a CD/DVD or LP?
Yes

How long does the "difference/effect" last?
I honestly cant answer this question, but when playing with both of the models available in SA i took to demagnetising each disc before use. It certainly didnt hurt.

PS i made the post to see the reactions of forum members, reviewers are also allowed to stirr a little occasionally, makes us feel more important, and no I own neither of the available devices. Thought that the Furutech De-mag worked better than the Bedini, but couldnt get past the selling price.

Wasnt punting the evening at Indaba either. just pointing out that there would be an opportunity for sceptics (I was one too) to have a look and listen.

Now if you'll excuse me, I'm going to align my cables with the moon, draw rings on my CD's, put stones on top of my speakers, and wait for the aura around my amp to be just right so that i can listen without offending the spirits :)  


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Offline DRNB

Re: demagnetisers
« Reply #23 on: October 18, 2007, 11:00:50 AM »
Will there be decent acoustics and loudspeakers on audition? If it is a case of listening to just another pair of so-so 6"/1" configured loudspeakers and acoustics like one might expect then I am not all that tickled.

Martin, Jeandre will probably have his Spendor range on display, which you know I'm not too impressed with, but the bigger one is a three-way design. Andre and Nico will have their Maestro amps there as well, on which a lot of mods has been done recently and and they actually sounds great (to me that is), maybe you've heart it? (After the mods been done I mean  ;D ). Andre was working on a set of Speakers which I hope he'll have ready by then.
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Offline GearSlave

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Re: demagnetisers
« Reply #24 on: October 18, 2007, 11:48:01 AM »
Now if you'll excuse me, I'm going to align my cables with the moon, draw rings on my CD's, put stones on top of my speakers, and wait for the aura around my amp to be just right so that i can listen without offending the spirits :)  

I can PROMISE you that you will have much greater effect downing a bottle of Jack Daniels than going throught that kind of effort (and yes, I know you were joking ;D). It will definately have that 'WOW' effect without spending R15k.
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Offline The Godfather

Re: demagnetisers
« Reply #25 on: October 18, 2007, 12:00:53 PM »
A VERY well known "trick of the trade" is to demo the system that you are wanting to sell second.

How will you not do this with a demagnetiser. Once it is demagged  - it is demagged.

And all my data would be gone :(

Offline Hi-Phibian

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Re: demagnetisers
« Reply #26 on: October 18, 2007, 01:15:40 PM »
Burn two CDs of the same source or use two identical pressing mint new discs. Put them on repaet for 2 days to really magnetise them.
Compare A to B to verify identical sonics, demag A  and then compare to B.
Do-able and done by 6 moons I think in their testing.
Harder for an LP, yes.

A similar effect that will at least show the possible influence of “residual” magnetic fields in CD is to just magic wand style “rub” but without touching your cd over a big magnet. No guarantee that you neutralise anything but you will change the state to some extent. This is audible on most fair resolution systems. Not necessarily better or worse but different…. Costs niks
« Last Edit: October 18, 2007, 04:37:20 PM by croak »
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Offline DRNB

Re: demagnetisers
« Reply #27 on: October 18, 2007, 01:38:13 PM »
A VERY well known "trick of the trade" is to demo the system that you are wanting to sell second.

How will you not do this with a demagnetiser. Once it is demagged  - it is demagged.

And all my data would be gone :(


Byrd, you shouldn't demagnatize your computers hard disk.  :o :D
"There is no shame in not knowing; the shame lies in not finding out." (Russian Proverb)

Offline The Godfather

Re: demagnetisers
« Reply #28 on: October 18, 2007, 01:59:21 PM »
But I also want that fabled sound. ;)

Offline Ampdog

Re: demagnetisers
« Reply #29 on: October 19, 2007, 02:16:34 AM »
Sorry, guys ... not good enough. :)

If my remarks were read carefully, it would have been apparent that there is a difference between "disregarding observations because scientific reasons were not immediately apparent" and "disregarding observations because it is immediately apparent that science proves the opposite".... or what else did I mean by "disregard of gravity"?

If such must be allowed, I am now going to state that: 3 + 5 = 11.

(1)  That was my (honest) observation under certain conditions. Nobody can dispute that as an observation because nobody else was present.
(2)  Science cannot (at present!) explain this.
Does that make such an observation entertainable? No, because science (and practice) CAN prove that such a statement is NOT tenable.

Shonver, your example of the loudspeaker wire is an illustration. It was not unclear to science what was happening, only to the (initially) incomplete application of science! Science never proved that such an occurrence was impossible, only that the characteristics of speaker wire per se are not the reason. And that was not found to be in error!

As to demagnetisation - the term used by the purveyers themselves: Since there is nothing to demagnetise, I rest my case. (The paint particle effect etc. were investigated just to humour people; there are instruments sufficiently sensitive to do that. It was found >200 dB too low to influence anything.) But as someone said, even if the code inscribed on CDs were inscribed on a disc of mild steel and thoroughly magnetised, it would make no difference. To repeat, one might as well run a sheet of print over the device and claim an improvement in clarity.

Stating magnetic influence as a possibility, yet again (with greatest respect) shows ignorance of the working of the signal detecting device - a laser beam. It requires a magnetic force of the order of a cyclotron to influence a laser beam in the least. To make it practical: Such a force would rip everything ferrous in the same room to pieces (never mind the metal chassis of the CD player in close proximity). In fact, laser technology is used as a measuring device under just such conditions where other means cannot function.

I have generally been regarded as the first person to respect observations at work (folks would be very surprised to hear what I have been investigating at the CSIR, just to be fair to some questions which came along sometimes). At the same time, once something has been "proved" or is trivially apparent (i.e. that 3 + 5 = 7.9999999), one cannot be expected to force established science into untenable moulds simply because someone has observed something, however convinced the person. I think that is reasonable?

(I do not wish to bore, but may I illustrate by what I experienced abundantly in my 40 years of work as police reservist. One is not proud to use car accidents as an example, but gather evidence from those who actually saw the incident, and one often wonders if they were present at the same scene. But they all state under oath - and they were not blatantly lying; simply perceptions. And our eyes are better than our ears.)

Has anyone tried to demagnetise car tyres (far more magnetic materials there than in a CD or vinyl record)? How do we know it will not make a difference?  ???

Audio must be the only branch of engineering where lack of basics' knowledge is considered a superior form of wisdom. (Anon)