[starman]

Ok, so I'm reading the NIN forums and I come across this thread that some NIN albums will be released next month via Best Buy on something called SHM CDs. According to what I read, they're supposed to sound better because the polycarbonate material allows the CD's laser to read the data off the CD better.

Bull. Sh*t.

Here's the thread. I posted in there.
http://forum.nin.com/bb/read.php?25,146855,176771

Someone explain this to me. Data CDs and DVDs don't lose data so how the HELL does this special material make the sound better? I call BS on the whole thing.

[analogika]

This was covered at length several times in Applications and elsewhere.

The main difference between audio CDs and data CDs is that audio CDs are read as a stream. If something isn't read cleanly, a CD player won't go back for a second attempt - the error correction will simply interpolate the missing values, making stuff up, or "faking it", as it were. On an audio player, a significant portion of what you hear at any time is actually generated by interpolation algorithms.

This is why the quality of the CD drive used actually *does* make an audible difference (the drive quality also strongly affects jitter problems), as well as the medium itself.

Edit: Actually, reading through that thread, a good test *might* be a lossless rip of both the SHM and the regular CD, since the effect of the polycarbonate isn't some magical audio enhancement, but simply more accurate reading by a laser. I'm not entirely convinced, however, that this will make a difference when ripping into iTunes, as iTunes might not read the CD as an audio stream, but rather as a data CD. I really don't know.



BTW: Please check your PMs.

[turtle777]

Why don't they make CD players that read the audio *data*, like iTunes does, and then play that ?
Wouldn't that guarantee that nothing is made up ?

Of course, scratches now might render the disc unplayable, unlike before.

-t

[Big Mac]

I suppose they'd be more expensive than regular CD players, and no one wants to pay anything more for a simple CD player. Who buys CD players today anyway?

[Doofy]

Originally Posted by turtle777 

Why don't they make CD players that read the audio *data*, like iTunes does, and then play that ?

I'm guessing backwards compatibility and not wanting to go off Red Book standards.

[Laminar]

Originally Posted by Big Mac 

I suppose they'd be more expensive than regular CD players, and no one wants to pay anything more for a simple CD player. Who buys CD players today anyway?

Car buyers.

[starman]

Ok, then if data's being read as a stream, what's the point of "16x sampling"? Is it reading the block 16x before making a decision? It seems odd that in THIS day and age we still can't read data off a CD properly.

[analogika]

Originally Posted by turtle777 

Why don't they make CD players that read the audio *data*, like iTunes does, and then play that ?
Wouldn't that guarantee that nothing is made up ?

I'm not sure. Maybe there is such a thing.
It would imply a much higher computation overhead that still wouldn't guarantee uninterrupted playback. And as for cost - the high-end market is already dropping optical media and switching to hi-quality (24-bit/96kHz) downloads, stored on network players.

[analogika]

Originally Posted by starman 

Ok, then if data's being read as a stream, what's the point of "16x sampling"? Is it reading the block 16x before making a decision? It seems odd that in THIS day and age we still can't read data off a CD properly.

The "16x oversampling" refers to the digital-analogue conversion stage, not the reading of the CD - basically, oversampling is one of several techniques that can be used to reduce aliasing and other artefacting by exaggerating bit values, making them easier to filter for analog reproduction (I'd have to look it up to explain it in any detail, though; it's been a while).

[starman]

Ah! Ok. THanks for that clarification.

[olePigeon]

While you're at it, you can buy a CD demagnetizer.

[Railroader]

Or a CD trimmer!

http://www.enjoythemusic.com/magazin.../audiodesk.htm

[- - e r i k - -]

Originally Posted by Laminar 

Car buyers.

Only because it's pretty mandatory. Give me a CD-less car unit that attaches to my iPhone/iPod any day. I bought the cheapest one I could find that had an AUX-in.

[- - e r i k - -]

Originally Posted by Railroader 

Or a CD trimmer!

http://www.enjoythemusic.com/magazin.../audiodesk.htm

Oh my. I'm inventing something to rape those gullible audiophiles as we speak. We OK'd that word didn't we?

[Railroader]

I actually thought about marketing goggles that were painted black to block all vision so as to cause "Severe auditory enlightenment and enjoyment of your superior listening selections" to gullible audiophiles. Alas, I am too lazy. Run with it. Yawn.

[Eriamjh]

Let me get my green Sharpie.

[analogika]

Originally Posted by Railroader 

Or a CD trimmer!

http://www.enjoythemusic.com/magazin.../audiodesk.htm

*ahem*

Originally Posted by analogika 

If something isn't read cleanly, a CD player won't go back for a second attempt - the error correction will simply interpolate the missing values, making stuff up, or "faking it", as it were. On an audio player, a significant portion of what you hear at any time is actually generated by interpolation algorithms.

This is why the quality of the CD drive used actually *does* make an audible difference (the drive quality also strongly affects jitter problems), as well as the medium itself.

We do know from over fifty years of experience that carving out the insides of turntable platter *greatly* affects the rotational stability and improves reproduction.

Makes sense to me that CD players might be subject to similar influences.

[- - e r i k - -]

I'm going to hire you as the spokesperson for my company analogika.

[analogika]

Originally Posted by - - e r i k - - 

I'm going to hire you as the spokesperson for my company analogika.

Trust me, if I think something's ****, I won't sell it.

But I do know enough about audio to know when to give reasonable benefit of the doubt.

[Railroader]

Originally Posted by analogika 

*ahem*

We do know from over fifty years of experience that carving out the insides of turntable platter *greatly* affects the rotational stability and improves reproduction.

Makes sense to me that CD players might be subject to similar influences.

Yeah, cause the CD will be perfectly balanced after trimming the edges...

[Laminar]

Originally Posted by Railroader 

Yeah, cause the CD will be perfectly balanced after trimming the edges...

My hand and a Dremel produces tolerances of +/- 0.001 inches.

[analogika]

Originally Posted by Railroader 

Yeah, cause the CD will be perfectly balanced after trimming the edges...

I dunno. Could be an improvement.

Can't say I care much.

[vmarks]

Materials and quality of manufacture do matter.

The metal material sandwiched between clear platters is aluminum in most cases. I've been in the booth on air when a disc de-laminated, the platter oxidized, and was unplayable.

In other observations, I pulled out a data cd-r I made in 1999 and attempted to read it in several computers. It had been stored in air conditioned temperatures, out of sunlight. It is now unreadable anywhere. I presume the dye that is encapsulated in the clear layers has reflowed and no longer contains the 1 and 0 that the laser light burned into it.

Bit rot happens.

[starman]

Bit rot only happened to me once with bad CD-Rs from CompUSA. Discs I bought in 1986 are still playable. I know it happens, just not to everyone. I also don't believe this new SHM crap makes the discs magically sound better.

[analogika]

Originally Posted by starman 

I also don't believe this new SHM crap makes the discs magically sound better.

If it manages to reduce read errors (I don't know enough about the material to judge whether it can), it *will* improve reproduction quality; no magic involved.

Why do you think mastering studios worldwide pay a premium for Taiyo Yuden CD-Rs? Longevity is not the only issue there. Jitter and error rates are, as well.

[Doofy]

I used to subscribe to a mastering and duplication magazine called "One To One" (yes, it was a fun read). And yes, there's loads of difference in product quality (raw materials, machinery it was made on, factory it was made in).

Example conversation with a bloke I used to know:

Doof: "So, I'm looking for some CDs, what're the best?"
Bloke: "Well, AAA brand is the best this week. BBB has been suffering with their source material lately because their suppliers have switched to a different brand of (whatever) chemical, and CCC's quality is down because their tea lady broke her leg last week and morale in the factory is down, yadda, yadda, yadda."

This conversation actually happened. For about two hours. I never asked him that question again (heh).

[analogika]

Mastering geeks.

[Railroader]

Originally Posted by Laminar 

My hand and a Dremel produces tolerances of +/- 0.001 inches.

I don't doubt it.

http://www.youtube.com/watch?v=8KvRe...eature=related

[Railroader]

Originally Posted by analogika 

I dunno. Could be an improvement.

Can't say I care much.

Or it could actually ruin the balance of a CD.

Enough to respond apparently.

[analogika]

Originally Posted by Railroader 

Or it could actually ruin the balance of a CD.

As I said - it might help. It makes enough sense not to just knock it sight unseen.

If the product is well-made, it won't ruin the balance. If not, well...it sucks.

Originally Posted by Railroader 

Enough to respond apparently.

Zip up your fly, you dolt: This isn't about a pissing match. I don't care enough ABOUT CDs to bother researching the product.

'kay?

[Railroader]

Originally Posted by analogika 

As I said - it might help. It makes enough sense not to just knock it sight unseen.

If the product is well-made, it won't ruin the balance. If not, well...it sucks.

Actually, from a very basic mechanical engineering standpoint it will very unlikely help.

And it might possibly ruin the balance of a CD.

There's more to balancing than just making a concentric circle from the center hole.

Originally Posted by analogika 

Zip up your fly, you dolt: This isn't about a pissing match. I don't care enough ABOUT CDs to bother researching the product.

'kay?

I'm sorry I pointed out your ignorance. No need for the name calling.

[Cold Warrior]

Originally Posted by Railroader 

I'm sorry I pointed out your ignorance. No need for the name calling.

You were inciting with the previous post.

Let's all try to stay on topic.