Great write up about how XRCD's are basically CD's

Liking this website RealHD a lot. Good stuff. Are they scientifically validated? Not by me. But seems legit. Below they said to forward the post, so I've copied and pasted it below.

http://www.realhd-audio.com/?p=1479

JVC XRCDs: A Blueprinted Company Disc:

Some of my closest friends are car nuts. In fact, my best friend loves to search out the perfect car for restoration and go for it. He’s done it with a ’65 Corvette convertible, a ’67 Porsche 911, Porsche 914 and is currently staring down years of work on a Triumph TR6. After a visit to Detroit this past summer, I couldn’t help but relate to the passion, patience and resources that it takes to do what he does (along with the patience and accommodation of his spouse…his garage has three cars in various stages of assembly in it!). Making recording is similar in so many ways (including the patient partner).

I bring up automobiles this morning because I remember the concept of “blueprinting” an engine. The auto companies produce a detailed specification for their engines using CAD computer applications. The actual milling of the metal and fabrication of the various parts introduces small errors (certainly within acceptable tolerances) that make the parts less than perfect.

However, if an engine is “blueprinted” then each part is brought in line with the exact specification as envisioned by the design engineer. The result is that a “blueprinted” engine is much closer to the ideal engine than those that you and I get in the cars that we purchase from the sales lot.

That’s what JVC does when they re-release a classic album on an XRCD type compact disc. The XR stands for “Extended Resolution”. XRCDs usually cost about twice as much as a standard CD. There is nothing extended about the resolution of an XRCD.



Figure 1 – BLock diagram of the HVC process for creating XRCDs.

Making an XRCD CD is like “blueprinting” an engine. The entire mastering and manufacturing process is more tightly controlled, the pits are positioned with greater precision and advanced dithering the input signal from 20 bits to 16-bits is employed (dithering is the process of randomizing the least significant bits of a series of words to minimize quantization noise). However, the end result is still a Redbook Compact disc, which means it can’t actually have any additional resolution! It might be more perfect CD but to charge double for simply meeting the Redbook specification seems a dubious model. It would be nice if all CD were made to this higher standard.

The JVC magic is in the mastering process. Recordings to be prepared for CD release are either analog or digital (PCM or DSD) when they arrive at the final mastering stage. If the master is digital then the transfer to the mastering system is done via a digital transfer. Hopefully, the master contains more than 16-bits so that the mastering engineer can manipulate the amplitude and EQ without losing any of the low level information. If the source is an analog tape (which it seems the folks at JVC count on when creating an XRCD) the conversion to PCM digital is done at either 20 or 24-bits using a patented “K2″ analog to digital converter. I’m sure the “K2″ converters are very good or at least were state of the art back when XRCDs were first introduced back in 1995, but converters have improved dramatically in the intervening years. Maybe they should come out with a “K3″ process (bigger numbers are always better).

The digital file is then sent on a “magneto-optical disk” to the JVC manufacturing plant. The engineers use a Rubidium clock to minimize jitter and down-convert the 20/24-bits words to 16-bits using a “super-coding” process. Remember that virtually all commercial music releases and absolutely ALL of the ones that were originally recorded on analog tape have less than 16-bits worth of dynamic range. In reality, the “K2″ process need only worry about getting 10-bits or 60 dB of SNR into the glass master. All of this craziness about 20 and 24-bit dynamics used on analog masters is overkill.

The replication facility encodes the master using EFM (Eight-Fourteen Modulation), which is a method of ensuring that there will be some “ones” in the digital stream to keep the optical reader happy. The resultant 16-bits is processed through a “proprietary Extended Pit Cut DVD K2 laser technology” to produce the glass master. This process uses a laser beam recorder (LBR) to etch the pits into a piece of glass. This glass master is then used to create stamping masters from which CDs are pressed.

The article I read says that the XRCD process creates “precise pit lengths to eliminate time jitters”. There is no jitter associated with the position or length of the pits on a CD. The data is read by the optical laser from the pits (and lands) and re-clocked within any quality CD player. Basically, it’s a stream of words pulled from the pits and then sent out to the DACs in a tightly clocked sequence. The original rubidium clock is old news by then.

I’ve posted on this topic previously. The resolution of a Redbook CD cannot be “extended” by using better mastering methods or custom processing of any kind. There will always be 44.1 kHz samples and 16-bit words on a CD. The best that can be said about XRCDs is that they are among the best CDs ever replicated. But the quality of the source audio and the quality of the mastering process determine the overall sound of the final replicated CD much more than the “K2″ converters or XRCD label. This is another example of marketing over media.

If the music you want is available as a normal CD file or download, you should acquire it that way. If you spend $35 on an XRCD, you’re wasting your money. Here’s a troubling and completely impossible statement from a review on Amazon of the XRCD of Steve Miller’s “The Joker”, “Without a doubt, this is a High Resolution CD”.

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Does this mean that some folks didn't know?

 

Whether it is a high resolution CD or not, Steve Miller's 'The Joker' still sounds pretty darn good on that XRCD. IMO of course. I only paid $16 for it too!

 

Ha...probably. I never researched it. I bought one XRCD and never bought another one.

 

Many (but not all) XRCDs are praised for their sound quality which is the result of the careful mastering process. The end results is of course just a CD, I never heard anybody claim otherwise.

PS: A HDCD does not have extended resolution either.

 

Attention to detail is what XRCDs are all about. Yes they are inherently limited by the resolution of redbook format. But they do take the redbook format to its limits by using a really excellent dithering process, as well as by ensuring that the disks contain as little jitter as is possible. Yes the mastering plays a significant role here as well. But mastering is not the only thing which effects the quality of the end product.

 

Exactly!

Could not be said more precise.

 

has anyone tested how much.....hmm...how to phrase this..... incorrect/missing data is present when using a cheapo CD player and a run of the mill CD from a major label release? (they can use the digital outs to rule out the DAC)

 

XRCD? never heard of them!

 

Are you serious?

 

Yep?

 

You really need to check them out. If you are a jazz fan, some of the best sounding jazz can be heard on XRCDs mastered by Alan Yoshida. They really show the great potential of the redbook format.

 

When all is said and done, XRCD is a 16/44.1 CD. It's all in the mastering. That said, many XRCDs, new and old, sound very good. I just never attributed that to XRCD. These discs are well-mastered CDs.

 

Basically, a XRCD is a Red Book CD manufactured to tighter tolerances than most.

 

That shouldn't be a knock against them. It's impossible to imagine my Chet Atkins/Mark Knopfler K2 disc sounding any better. This author goes from indicating that these are among the best CDs ever replicated to "marketing over media." As for the quality of the the source material and the mastering process, everybody here should know that or not be participating in the discussions.

 

The few that I have do sound better than their standard counterparts - maybe its the extra dab a marketing magic. But the author is right... after close examination, they do look just like a CD

 

In the case of XRCD the mastering as we generally term it here, and the whole mastering chain up to the pressing.

 

So far nothing, in the diagram suggests that Victor-JVC does anything different with the physical manufacturing of regular CDs they press for their labels (Victor Japan, etc.) and the ones they press for other labels as a manufacturer.

The only thing different is the mastering process, because they own the process, not the original record label. That's what matters and where the extra care results in good sound.

Blueprinting an engine's purpose is to get 1) tolerances to near zero 2) additive tolerances to also be zero (i.e. if part A is on the left side of the spec and part B is on the right side of spec, but both in tolerance, the cumulative error then may be out of spec). The reason it matters is that tolerances matter when run to the engine's limits in terms of maximum output and engine life span. An engine blueprinted and not run to its limits, will still run better, since vibration and tolerances are improved.

What does this have to with CDs? Has JVC improved anything physical here that 1) does not already exist in their process 2) exceeds a theshold that was a limitation. My opinion is definitely no.
These are not records where, like engines, optimization is ongoing.

Another thing to consider is that JVC is already one of the premier replicators in the world in terms of block error rates for quality.

 

Which brings you into their Mastering article. I'm enjoying the info this site is putting out and know of the people, but I find by posting it in a forum it helps me get a better opinion on whether I'm understanding it correctly. I have no connection to this site, and they do say to share. So, I know there are plenty of people on here that can opine on these.

EQ'd Masters

By Mark Waldrep
I was in the middle of writing my post this afternoon (I usually write in the mornings but I have university commitments on Mondays and Wednesdays.) when the phone rang. An engineer friend of mine called to chat for a few minutes. Last week, he had heard the sentence that I contributed to the NPR piece on Cookie Marenco of Blue Coast Records.

My friend is a very skilled and experienced mastering engineer at one of the major record labels. He’s been working there for 12 years and was recently put in charge of their mastering studios. As we got talking, he mentioned that he has been doing a lot of work for “one of my main competitors”. It’s his job to process the master tapes that are being licensed for their high-definition digital download site. What he and I talked about was the nature of the masters that are used to generate the high-end digital transfers that customers purchase on the site.

So first I need to provide a little background information.
We did talk about this stuff when I went through the notion of what’s a master and what’s a copy of a master. Well, there’s actually more to it than that. It turns out that there are flat masters, EQ’d masters, vinyl masters, CD masters, cassette masters and archive masters as well. That’s why the engineers that work in the mastering rooms are so busy…they have to keep track of many different versions of the same record. They are all different.

A flat master is the mix as delivered by the artist, producer and mixing engineers. In the past, it was a 1/4″ stereo analog tape at 15 ips (on rare occasions it might a 30 ips master). This is the master that the artist approved. It gets handed over to the mastering house and processed for whatever delivery format is to be included in the project’s release. This might be a vinyl LP, an analog cassette CD or iTunes…or now a high-resolution download website. The processing for each of these formats is different.

The EQ’d master is a transfer of the master tape that has had it’s timbral characteristics changed through the use of equalizers. An equalizer is basically a fancy set of tone controls. There are parametric EQs, 31-band graphic EQs, three-band EQ and a few more types. A mastering engineer also has a variety of filters that they can use to change the “color” of the flat master. There are notch, high-pass, low-pass and bandpass filters.

In preparing a flat master for release on vinyl, the mastering engineer makes alternations to the flat master in order to accommodate the technical limitations of vinyl. He specifically mentioned the regular need to collapse all frequencies below a certain frequency into mono. This is done to prevent the large low frequency undulations from causing the cutting head to move into negative space…above the surface of the lacquer master disc. You don’t have to do this for a CD release…the two channels are complete discrete (not so on vinyl LPs…this is the crosstalk specification).

Another very common adjustment made to vinyl releases is the extreme elevation of all frequencies between 12-15 kHz. According to my friend, “vinyl can’t physically deliver much higher than 15 kHz” so they push the high end to get as much brightness as possible onto a medium that has difficulty in that register. The folks that are all about vinyl LPs being the best representation of a recording are kidding themselves. They get a particular flavor that is unique to that format. It is NOT the same version that you would experience on another format. And it’s not best representation of the album.

But it just might be the version that is transferred to a 192 kHz/24-bit soundfile because it’s convenient, inexpensive to produce and doesn’t require any artist approvals.

We’re taking a closer look at the various “masters” that are created from the flat master mixes that are delivered and approved by the artist, producer and engineers.

I guess the basic question is which “master” do you want when you repurchase a “so-called” high-definition or high-resolution audio file from a digital download website? If you’re experience with a particular album has been strictly from a vinyl LP version, then you might be pleased with the typical HD downloaded file. Why? Because the EQ’d master that was created in the process of cutting the lacquer master for vinyl duplication is often used as the source for the transfer to the HD master soundfile. This is a huge problem!

As a former disc mastering engineer, I can tell you that the preparation of a vinyl LP is very different than the preparation of a CD or even a cassette release. The flat master mixes are always used as the source. But the steps that follow are dependent on the delivery format. And they all sound dramatically different.

For example, back in the days of cassette duplication, the mastering involved creating a version of the flat master that could be used in a bin loop duplication machine. An entire side of an album was made on 1/4″ 2-track analog tape and then formed into a loop (that’s the “loop” part of the process!). This was placed in a “bin” as well as fed over the playback head and capstan and puck roller (this keeps the speed regulated). The cassette master tape was played faster than the normal playback speed (usually 2x or even 4x) to a bank of duplication cassette machines that recorded on the tracks of an 1/8″ wide piece of tape (running faster as well). They would just duplicate a lot of passes before cutting the tape and loading it into the cassette shells (called C-0s because they came without any tape inside them).

For the vinyl LPs, the mastering engineer had to adhere to the practices of preparing for vinyl turntable playback. There is lot of considerations that a disc cutting mastering engineer has to think about based on the very sever limitations of the vinyl LP format. Some are technical and some are creative. I mentioned yesterday that the low frequencies are routinely folded to mono below a specified corner frequency (usually 50-100 Hz). The result is a narrowing of the stereo image to ensure that the walls of the grooves are correctly formed. But there is a sacrifice that must be made to EQ’d masters that ultimately get delivered to the vinyl LP copies. And that’s not all.

On the “creative” side of the job, the mastering engineer alters the dynamics and the frequency contour to his/her own taste and in keeping with the “best” practices of the industry. The record company pushes for louder and brighter (just like the video displays in a Best Buy store that has the brightness and contrast turned up way beyond calibration to make the TVs attractive!) and usually the mastering engineer complies (if they want more work from the company). This creates a less than ideal version of the flat master that the band approved and liked.

I’ve heard from a few friends that are currently working as mastering engineers and they confirm that the fidelity of the “remastered” discs is not their primary concern. Things need to punch and sizzle and that means that the EQ’s master used as the source for the new HD download files is NOT the best source. No wonder I hear from so many customers that are unhappy with their recent downloads of a classic album or track in so-called “HD”.

I have said previously that these are not “HD” according to my definition…many have come from standard definition sources. But it seems that many if not most of the transfers are using the EQ’d master rather than the flat master or a newly re-mastered version, which is the worst version to make available to customers.

Tomorrow I’ll talk about the right way to do this…something I’m personally trying to implement as iTrax.com tries to expand.

http://www.realhd-audio.com/?p=1612

 

The iPad is basically a tablet computer

XRCD is not a format, it's a trademark

 

Back in the 90s one of my buddy's engineering classes at NC State did something along these lines. They did confirm that there was less error correction going on when playing back MoFi gold discs vs. standard discs of the same title. Or so he told me.

 

Yep. Some people still seem to think it's a format. Amazing.

 

My dream: INXS on XRCD.

 

I often wondered whether K2 releases that overlap XRCDs, are just XRCD files produced on a standard CD production line? Why would JVC bother to remaster for K2 when they already have a perfectly good XRCD masters at hand?
Has anyone done a sonic comparison?
Just wonderin', Trevor.
P.S. I have purchased many Fantasy K2 jazz titles and like their sound quality. XRCDs are out of my price range.

 

My K2 XRCD by Sonny Rollins is really grainy sounding, so - like you - I never bought another one. My 70's vinyl of the same reissued title from 1957 sounds far more realistic and listenable.