Propeller Head Plaza

Technical and scientific discussion of amps, cables and other topics.

Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.
You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.

You must login to use this feature.

Inmate Login

By default, logging in will set a session cookie that disappears when you close your browser. Clicking on the 'Remember my Moniker & Password' below will cause a permanent 'Login Cookie' to be set.

Moniker/Username: The Name that you picked or by default, your email. Forgot Moniker?	Examples "Rapper", "Bob W", "joe@aol.com".
Password:	Forgot Password?
	Remember my Moniker & Password ( What's this?)

If you don't have an Asylum Account, you can create one by clicking Here.

Our privacy policy can be reviewed by clicking Here.

Inmate Comments

From:
Your Email:
Subject:

Message Comments

Original Message

RE: So what's the deal with CD demagnetizers?

Posted by geoffkait on November 12, 2015 at 03:34:58:
The static electricity is a separate issue. More on that later. But back to the question, how can the metal layer be magnetic to any REAL degree? It is sputtered on so the layer is extremely thin. You can sometimes SEE through it it's so thin. In addition the aluminum or nickel or gold layers are quite pure. If there are ANY ferrous impurities at all in the metal layer - which is dubious - there could not possibly be enough magnetism to account for much of anything. You might as well suspect the polycarbonate of impurities. Now, if someone said that 24 carat Gold CDs were impervious to demagnetizers I might go along with you as far as aluminum or silver or nickel CDs go. As for your question regarding magnetism in LPs, I suspect the same argument applies. There doesn't appear to be sufficient ferrous impurities in either the vinyl or the ink on the label to affect anything sonically or to be affected by a demag.
The other problem of course is, even if there were sufficient ferrous impurities in the metal or the ink to produce a "mild" magnetic field WHAT would the magnetic field affect that changes the sound? Is it the electronics, the laser beam (yes, I know it's electromagnetic), the servo mechanism, what?
Nevertheless, I employ both a demagnetizer and a tourmaline negative ion gun on CDs simply because I believe it's better to be safe than sorry. Hahahaha
You wrote,
"After all we are talking about optical optimization on a microscopic level."
That's assuming the magnetic field, if there is one at all, affects the optical reading process and not something else. And even if there is a slight magnetic field and it DOES affect the laser reading process it better do it VERY QUICKLY since the photons are moving at the speed of light and the distance they travel between the laser output and the photodetector is what about half an inch? :-)