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So what's the deal with CD demagnetizers?

97.34.193.249
Posted on November 8, 2015 at 14:55:08
geoffkait
 What's the deal with CD demagnetizers?

OK, I've got an innocent question. How do CD magnetizers work? I'm a little dissatisfied with reviewers' or anyone's ubiquitous comment, "I have no idea how it works but works it does." Whether it's the Radio Shack bulk tape eraser, the Walker Audio Talisman, or another demagnetizer, pretty sure Furutech sells them, too, what's the mechanism for how they work?

So, anyway, we all know that demagnetizing CD prior to play does improve the sound. If you haven't tried it trust me it works. But the closer you look at this phenomenon the more mysterious it becomes. The main question I have is even if there is some magnetic materials in the CD, you know, in the ink used for the CD label graphics or in the metal layer, surely the magnetic field arising there from must certainly be very very small, given that the ferrous impurities would by necessity be perhaps what less than 0.001 % of the material? But for the sake of argument let's say there is SOME (extremely minor) magnetic field in the material of the CD resulting from the ink and/or the metal layer, why would that mag field hurt the sound? And by the same token why would demagnetizing the CD improve the sound?

One assumes the magnetic field builds back up over time since the demagnetizers must be employed on the CD every so often. Even assuming some small magnetic field, any magnetic field, associated with the CD how would that affect the sound one way or the other? Anyone have any insights?

Geoff Kait

 

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RE: How about encasing the mechanism?, posted on July 24, 2016 at 16:36:43
Tweaker456
 One big problem with your analisis JURB is that it does have a fairly obvious effect on the sound of a cd. Have you ever actually tried it, pray tell? I just hate having to agree with Geoff on something. Tweaker

 

RE: How about encasing the mechanism?, posted on July 26, 2016 at 13:19:28
geoffkait
 That's all what I already stated more or less in my OP. And that's precisely my whole point. That there's no obvious way that demagnetization of CDs should work. Yet we have the testimony of a gaggle of audiophiles that demagnetization of CDs works. Are they are all hallucinating?

 

RE: How about encasing the mechanism?, posted on August 8, 2016 at 18:14:39
horn kid
Audiophile

Posts: 128
Joined: November 2, 2014
 Oh, they work, as well as VPI Magic Bricks (gee, everyone needed them, then nobody....), Mpingo Wood blocks (so many rooms at shows needed them, but those same exhibitors now don't....must be the hotels built them in), Shakti Stones, and all the other totally useless crap that works only in the imaginations of audiophiles......for a discreet period of time.....then stop working......

But repeat over and over: "I hear it, I hear it, I hear it, I hear it...." and eventually you won't be worried about real life, your insecurities, your imperfections, you know your system is perfect because the monk selling the stuff told you, the reviewer on that site told you.....and all is well in that nice dream world of audio accessories.

 

RE: How about encasing the mechanism?, posted on October 22, 2016 at 09:33:44
geoffkait
 Always nice to hear from the hoi polloi. Sorry to hear of your non success with tweaks. Thats a shame.

 

RE: So what's the deal with CD demagnetizers?, posted on November 20, 2016 at 22:34:10
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
 Well, everybody DOESN'T know it works.

And if the CD IS magnetic in some fashion, the voltage generated in my coil experiment should drop a LOT when comparing before and after demagnetization.

Has anyone tried THAT?
Too much is never enough

 

RE: A Serious Question., posted on December 16, 2016 at 01:24:46
thetubeguy1954
Audiophile

Posts: 6112
Location: Orlando, Fla
Joined: January 7, 2001
 Ok guys, PLEASE don't tear me a new one if this idea is crazy because although I've been in this hobby for the past 50 years, I have absolutely no technical grasp on how most of the actual components work. So here's my serious question: "If CDs develop some sort of magnetic charge that must or should, be removed in order to achieve better sounding playback of the CD. Why not just have an electromagnet built into the CDP that bathes the CD in it's electromagnetic field when the CD is being played?" Wouldn't that do the same thing as a bulk tape eraser or other devices being used?


Thetubeguy1954 (Tom)

Central Florida Audio Society -- SETriodes Group -- Space Coast Audio Society
Full-range/Wide-range Drivers --- Front & Back-Loaded Horns --- High Sensitivity Speakers


 

Whoa! What?, posted on December 16, 2016 at 04:07:30
geoffkait
 Why would you want to bathe the CD in a magnetic field? We're trying to get rid of magnetic fields. Maybe you mean an on-board demagnetizer that could be activated every so often by pushing a button.

 

RE: What the...?, posted on January 17, 2017 at 20:19:47
CD
Audiophile

Posts: 597
Joined: August 26, 2003
 Having tested hundreds of rips against databases, I have excellent empirical evidence that a $29 'puter drive can get a 100% accurate read of a CD. It's a pretty robust technology.

I do however get excellent results from hanging chicken feet over my server.

 

RE: What the..., posted on January 18, 2017 at 15:28:22
geoffkait
 That's what everybody says.

 

RE: So what's the deal with CD demagnetizers?, posted on June 15, 2017 at 04:29:48
beach cruiser
Audiophile

Posts: 7051
Location: so cal
Joined: September 24, 2003
 The deal with cd demagnetizers is that a fool and his money are soon parted, or don't believe everything you read, that kind of advice against a cruel world comes first to my simple thoughts.

Jokes aside, one identifies sound only with the brain, and the brain has no self awareness. It decides what it hears , take it or leave it. If it gives you good information, or bad, that is all it knows, and the judgement is always subjective. If you think it sounds good ,it will, and does.

All the charlatan has to do is to make you think the product works, and then it, the suggested illusion, will work.

IN my years reading audio, this stuff comes and goes. It used to be a felt tipped marker was the Cd fixer upper, than a commercial product came out and it had to be a special color. I think you can still buy a magic clock for hi fi nuts, and the same company under discussion here also makes a vinyl (!) demagnetizer, but the special rocks are long gone. All 0f these products were very well reviewed, apparently by idiots. not being able to explain the results of your review by not understanding how the products works is weak, too thin for me and my poor little wallet.

A simple illustration of brain subjectiveness.One can see this easily with eyesight, and optical illusions.

Sometimes, unless it is explained to you , you miss the illusion, your brain doesn't see what the other guy sees, although it is always there for both. It is the brain that interprets the image, and it is always subjective . For instance, when people think they see ghosts, the ghosts wear clothes. How do ghosts get clothes, or need clothes, other than the brain has misfired and generated the image.

Sometimes one will stumble , an error while walking, and you realize you have made an error . The body has awareness, you know when a muscle misfires. Not so with the brain, where the reality is always subjective, and a misfire can be anything. As seen with brain disease, where people live in a long term false reality caused by mental illness, and not a passing simple suggestion, such as ,did you hear that?

If one considers hearing, it does some things better than others. One can easily hear a sound down the street, and know it is around the corner, even with the window closed. One knows this without thought. Pitch takes some concentration, and is often a learned skill.

With these results, It is suggested human hearing developed in the tall dry grass savannas. Where escape was the primary goal, not sonic accuracy. If you think you hear something, you run, to keep off the menu as special of the day. A misfire is no big deal ,not so with the food safety senses 0f taste or smell .

One knows the hand is quicker than the eye, everyone knows the hand doesn't leave the arm, it is just moving too fast for your optical system, so it is no longer visible. Few people consider how hearing works, it is not perfect, and is very prone to suggestion. Consider a smile and a refreshing beverage as a sonic upgrade before buying anything with results that can't be measured or function explained beyond buy it, it works.

This subjective stuff is slightly irritating to me, as is most intentional ignorance . When hi fi was new, test were made, and results were used as a way to understand the product. However, how to measure audio was also new, so some sonic results were not able to be measured. This "unable to know ' because the measures were being developed has stuck, in part because nothing will sound the same at different times, it is up to the brain to tell you how it sounds.
Just like if a guy in a lab coat handing you cheap wine in a fine old bottle and it tastes better.

With cars, performance can be measured. With audio, the finish line is in your head. But you can still buy a turd in either situation. Still, it you think it sounds better , that is your reality. Just don't pay too little or it won't work. I was once cruising the web and saw a single wooden hi fi knob for $450 with the statement is was sonic magic.

IN my personal experience, I was helping a buddy set up his new Bose 901 speakers, a trash design that used multiple midrange drivers only, with heavy signal processing to generate the bass and highs. I was plugging in wires and we were thinking if we could hear anything, sometimes we thought we heard something, as I tried different inputs. Then I plugged into the correct socket, and thinking we heard something was gone, we could easily hear the signal processor and the thinking I hear something was over. Yet for a while there, when we were trying to hear something, we thought we did, kind of, at times.

 

stuff I left out. , posted on June 15, 2017 at 12:44:54
beach cruiser
Audiophile

Posts: 7051
Location: so cal
Joined: September 24, 2003
 After all that, I forgot to mention the solution to understanding illusion from audio fact. The double blind test. Where the merchandise is played behind a curtain, or out of sight, and listened to, with and without the object in question in he signal chain., enough times to figure it out.

I seriously doubt I could hear how a magnetic field would effect information carried by light in the infrared spectrum. AS far as magnetic vinyl , prove it. One would assume the magnets in the cartridge would be more of a concern.

 

Another thing you left out BC , posted on June 18, 2017 at 16:50:22
Tweaker456
 You didn't try it.

 

easy to prove one way or the other, posted on May 13, 2018 at 16:40:07
BillWojo
Audiophile

Posts: 186
Location: NJ
Joined: July 7, 2017
 This whole post sounds like total BS to me but there is an easy way to prove it. Take a CD, listen to it and than spray some adhesive on the label side. Take a prerecorded length of magnetic tape and cut it into lengths to cover the label side. Now place this CD back into the CDP and listen to it. Sound the same? Well, it shouldn't according to the "TRUE BELIEVERS". Now demag it and play it again. Sound the same?
CD is an optical media. Get over it.

BillWojo

 

RE: easy to prove one way or the other, posted on May 14, 2018 at 11:23:09
Tweaker456
 Well I must say it is easy but not quiet as easy as doing a before and after test with just a demgnatizer, but that's just following like first grade logic, but please let us know how your easy test works out. Quite a few of us here would go way way out on a limb and speculate that your test, before the demag would in fact change the sound. As always some people can hear things and some can't. If after you spray a cd and put your tape on it, listen, and come to the conclusion that it did not effect the sound, more power to you. The less sensitive one is to changes in sound the less they have to do or worry about when going about improving one's system, if in fact that is a goal. The goal of nay saying, especially before actually trying things is the easiest of all. Tweaker456

 

RE: easy to prove one way or the other, posted on May 14, 2018 at 21:00:31
BillWojo
Audiophile

Posts: 186
Location: NJ
Joined: July 7, 2017
 Not going to waist my time on it. I gave a simple test procedure for anyone to try it out. Best would be to make two identical CD's with magnetic tape on it, one that has been demagged and one with recording on it. Then do a blind A/B test.
Just a small piece of magnetic tape would have WAY more magnetic property than a whole stack of CD's. So who's game?

BillWojo

 

RE: easy to prove one way or the other, posted on May 15, 2018 at 06:56:46
Tweaker456
 Why bother believing your own ears. Just foam on.

 

RE: So what's the deal with CD demagnetizers?, posted on October 12, 2018 at 23:53:20
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
 The most common impurity in an aluminum sputtering target would be silicon, and than only to the tune of maybe 1% to 1 1/2%. That is the Maximum Uptake of Si in Al at temperatur of maximum solubility.
The reason is that in semiconductor processing, which shares some equipment with the manufacture of CDs, when the Silicon Devices are 'annealed' (heat treated) the silicon in the electrical contacts will 'spike' up into the aluminum conductor. But NOT if the Aluminum already contains silicon.
Too much is never enough

 

RE: How about encasing the mechanism?, posted on May 28, 2020 at 21:09:22
pictureguy
Audiophile

Posts: 22597
Location: SoCal
Joined: October 19, 2008
 Mu Metal


Too much is never enough

 

RE: I hear substantial benefits from lifting the cables off the floor, posted on June 18, 2020 at 14:17:15
I'm an Audio God
Audiophile

Posts: 13
Location: S London
Joined: February 14, 2004
 Hi discussion. I thought i would jump in as i didn't think it is sensible/rational. However the only thing i can think of (and this could be BS, i don't know and don't have the facilities to test. But demaging a CD just before playing would induce eddy currents in the metalized layer which could heat it up a small amount.
If that effect is measurable which it should be -if it can be heard?
Who know's? just my thoughts, maybe others know more -so just throwing it out there.

 

RE: I hear substantial benefits from lifting the cables off the floor, posted on October 8, 2020 at 06:40:48
geoffkait
 Who's Eddy?

 

RE: So what's the deal with CD demagnetizers?, posted on January 15, 2021 at 19:10:42
Mushroom Soup
Audiophile

Posts: 310
Location: Western New York State
Joined: November 1, 2003
 Well, I was in a store once, back when cds were a new thing. A cd was playing and it sounded kind of horrible. I said "That sounds kind of horrible". He took out the cd, put it in a little handheld thing, put the cd back in and it sounded better. I certainly had no expectations needing to be fulfilled. I was in fact surprised. There are always going to be skeptics, but a lot of the time skepticism is just another word for ignorance.

 

RE: So what's the deal with CD demagnetizers?, posted on January 16, 2021 at 14:49:12
geoffkait
 What is perhaps even more shocking, and I use a handheld demagnetizer myself, is there can't possible be very much material anywhere on or inside a CD capable of being magnetized. Most likely the Earth's magnetic field is stronger than a CDs magnetic field when it's all charged up, so to speak. Yes, I'm aware that some theories of demagnetization include ferrous impurities in the metal layer and ferrous material in the ink used on the CD label, but come on!! Cut me some slack!

 

RE: So what's the deal with CD demagnetizers?, posted on March 22, 2022 at 07:32:25
jrlaudio
Industry Professional

Posts: 76
Location: New York
Joined: November 2, 2012
 The simple answer ... when makers of vinyl de-static devices (a real thing that was useful) thought their market was drying up when it appeared vinyl might go away, they needed a product they could continue selling.

These things are highly dubious IMO and don't let anyone tell you otherwise. Digital electronics, especially optical ones, are not affected by static or magnetic charges on a disc. One of the advantages of the format.

 

RE: So what's the deal with CD demagnetizers?, posted on March 23, 2022 at 12:10:24
geoffkait
 I'll be sure and not let anyone tell me otherwise. By the way, didn't you know you can't prove a negative?

 

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