Disc tweaks

[Balthazarr]

I've read somewhere about tweaking cd's by sanding.
Done the edge painting for years.
I'm wondering if sanding the edge improves sound at all or is it just to allow better adhesion of the paint?

 

[motaboy]

How can a CD's sound improve?
A CD is just grooves and hills that represent 0's and 1's.
Those 0's and 1's can come in any form, be it a CD with paint or without. It has no effect on the sound quality.

 

[440hz]

I have been putting the paint in my ears, am I doing it wrong

 

[Balthazarr]

How can a CD's sound improve?
A CD is just grooves and hills that represent 0's and 1's.
Those 0's and 1's can come in any form, be it a CD with paint or without. It has no effect on the sound quality.

Wrong, try it. Use green though. Take a poorly recorded disc and see if it makes a difference.
I've read black works as well.
Just the outer edge, not the whole cd.

 

[440hz]

Wrong, try it. Use green though. Take a poorly recorded disc and see if it makes a difference.

So you mean it helps the player to read discs as in stops it skipping on dodgy CDs. If you are saying it somehow changes the sound then me no believy until I double blind heary. I tried to make that rhyme and I think I succeeded.

Actually to be fair I have never tried it so maybe I will A/B a couple of discs but get my gf to do the changin' I really cannot think of a way that could possibly make a difference other that something to do with helping the laser read the disc. But even then how could that make a difference? The laser is so weak except for at it's focus point I just cannot see how that would change anything. It certainly cannot change the information that is already on the disc, and as was pointed out this is digital information, it tells the player what freq. a noise is and what amplitude that noise is and when and for how long and which channel etc etc. Its not like an LP which is analogue, the stylus reads the grooves directly off the surface and spilling beer on a record is a bad thing

 

[440hz]

Shit I just realised that a blind test for me is stupid. I already don't believe it can make a difference so I will not expect to hear any. It would have to be a BIG change I reckon for me to change my mind, I will do my best but I really think it would have to be very obvious change to convince a sceptic. However we could test someone who believes it does make a difference.

 

[Aage]

Blind tests have NOTHING to do with it.

Shit I just realised that a blind test for me is stupid. I already don't believe it can make a difference so I will not expect to hear any. It would have to be a BIG change I reckon for me to change my mind, I will do my best but I really think it would have to be very obvious change to convince a sceptic. However we could test someone who believes it does make a difference.

You just have to BELIEVE...

Historical note: it was found out in the early days of IBM computers that green punchcards gave lower data error rates.

And if you believe that...

 

[Balthazarr]

I really cannot think of a way that could possibly make a difference other that something to do with helping the laser read

Bingo. The light gets scattered since the surface is not perfectly smooth and internal reflections at the surface make their way to the edge and are reflected back toward the beam.
Greening the edge absorbs this and prevents the interference.
The there are the components that the irregular surface presents.
Error correction can do only so much.

I've heard the difference on numerous discs. Whenever a new one I bought sounded harsh and hollow, treating in this manner helped.

 

[Aage]

It's like arguing over speakers

Greening the edge absorbs this and prevents the interference.

Well, there's two schools of thought on that one. See this link to Urban Legends (snopes.com) for another side:

http://www.snopes.com/music/media/marker.htm

 

[Balthazarr]

There's always two schools of thought on virtually everything.
I see that the article implies no difference between analog and digital playback also.

 

[Charivari]

Shit I just realised that a blind test for me is stupid. I already don't believe it can make a difference so I will not expect to hear any. It would have to be a BIG change I reckon for me to change my mind, I will do my best but I really think it would have to be very obvious change to convince a sceptic. However we could test someone who believes it does make a difference.

You never know. I held the same opinion that black CD-Rs were a load of bunk, or worse, until I happened upon some just because they were on sale and thus cheaper than my regular favorites. I burned an audio CD as per usual, discovered I already had a regular CD-R copy of it that I had forgotten about, and was surprised that when compared, the black disc sounded a fair bit better. I went into this strongly believing that I would hear no difference, but I was proved otherwise.

So, maybe this other stuff has some merit, though the $500+ CD lathe to trim down the edges is pure grade snake oil imho. A pen or black CD-R is certainly a much cheaper thing to try out and if you hear nothing, as you think most likely, then no loss.

- JP

 

[440hz]

Well, there's two schools of thought on that one. See this link to Urban Legends

Yeah what they are talking about in here with the testing is my point exactly. A blind test on a sceptic might not tell you much because they don't expect to hear a difference, and they could lie to mess up the results, even if they were doing it subconsiously.

But a believer should be able to pick the difference and score better than what you would expect by chance if they can here a difference. People can claim that the science just doen't know how to measure the effects or whatever, it doesn't matter. If you can't pick the difference in a blind test, there is either no difference, or at least no audible difference, game over.

 

[motaboy]

It makes sence that it may help read scratched or damaged discs.
But to IMPROVE the already recorder information is impossible. It's not MP3s we're dealing with.

 

[andy]

Any properly functioning CD player playing a disc that's in good condition will read the data off the disc perfectly. There will be few, if any uncorrectable errors. If an uncorrectable error is audible, it will show up as a pop in the music, not as some change in the character of the entire piece of music. A large number of errors will sound like loud white noise. If you don't believe me, extract a CD track to a computer using a bunch of different disc tweaks, then compare the files bit by bit. Every single one should be identical unless something is wrong with the disc, or drive.

The same data going into the DAC = the same sound coming out. Also, the DAC doesn't see the raw data coming off the disc. By the time it gets to the DAC it's been buffered in RAM and error corrected and decoded into PCM. Unless something is grossly wrong, the data going to the DAC will be identical on every play. The DAC and everything that comes after it is where the tweaking will make a difference.

 

[Balthazarr]

So last night I listened to Porcupine Tree cd that I made and it was grating.
Applied the "paint" to the edge and tamed it considerably to the point I actually enjoyed listening to it.
Tried 3 times previously and noticed how strident the sound was, but for other reasons didn't finish auditioning the disc.
This time made a point of completing.
Say what you want about psychoacoustics, but my ears didn't "bleed" this time.