Help me get this CD mastered!

[Postman]

Here's my delimmae, I mixed a show full of music. They want to make a CD of the music. I've already leveled/eqd all 36 songs, which total approx 74 minutes. I was about to put them onto a CD (Toast 10), and suddenly a list of ISRC codes shows up in my inbox. It has become clear that the clients are planning to send one of my CDRs directly for replication by Sony DADC. "We've done it before." Okay.

I just got a link to Sony DADC replication specs, and I am getting nervous. First, can Sony actually just take my CDR, with ISRC codes inserted, and stamp out CDs from that? Also, the Sony page says "Maximum User Data Capacity: 681,984,000 bytes per disc" When I do some math I figure that to be 64.4 minutes. The clients are not sure I am right and neither am I certain. HELP mE!

Thanks.

[minister]

Hi Postman,

You can embed ISRC codes right in Toast. Not sure which version you have, but you can certainly do it in 8.

http://www.roxio.com/enu/support/toa..._features.html

I know a number of excellent ME's and they send CDR's (for big time and label clients) to plants all the time. DDP is far more rare, not worth the hassle, and no guarantee.

Redbook standard is a maximum of 74 minutes which is 650 Megabytes. Many plants have relaxed this. Sony appears to allow over 680. You should be fine.

EDIT: One thing that I do (in the rare event I Master a music CD) and that many ME's do is to give the client 2 discs. One as a listeing Ref and another to give to the plant. Seal the one destined for the plant. This way they won't scratch it, put it in their car, use it as a coaster, hang it from a Christmas tree, or put it into iTunes and unwittingly convert it to MP3's and then burn another copy which they send to the plant. Happens all the time..............

[Postman]

Thanks Minister, you are reassuring. I rarely deal with CDs for anything more than casual one-offs and never think about this stuff. Toast 10 will insert ISRC codes.

Calculating the actual space I need for 74 minutes is what has gotten me confused. I cannot get the math to work. It must be my mistake, but I don't want to burn the cd until I am sure of what I am doing.

Here is my math to figure audio data rate. 44100 bitsPerSec * 16 bits * 2 channels = 1411200 bits per second. There are 8 bits per byte, so 1411200/8 = 176400 bytes per second used for audio playback.

For 74 minute playtime, 74 minutes * 60 seconds = 4440 seconds.
4440 seconds * 176400 bytes per sec = 783,216,000 total bytes needed. There are 1048576 bytes per megabit, so I need 747 megabytes? This cannot be right.

Sony's spec page states I can use no more than 681,984,000 bytes of audio data, which is 650.39 megabytes. By my math, that only allows for 64.4 minutes. So, what am I calculating incorrectly?

Good suggestion to seal a "master". That will give them 1 audition disc and 2 for Sony (incl. backup).

[minister]

Hi Postman,

Well, I ran back to my Ken Pohlman book, it states (I am condensing quite a bit) that CD-Rom Mode 1 is 2,048 bytes/block and 74 min is 681,984,000 bytes per disc. An audio CD, such as the CD-R you are burning is 2352 bytes/block and 74 is, indeed as you say, 783,216,000.

I spoke to an ME friend of mine and he says he does CD-R's at or near (and a few over) 74 frequently and there have been no ill effects. However, they may ask you to sign a waiver. Some older players don't like them so they won't play etc.

The take home message is : call Sony DACD and ask them, inquire about the waiver. If they say, yes, indeed there will be one, advise your clients about it.

If you want to contact some good ME's to discuss, contact me off-list.

[Postman]

Thanks, again you are helpful.

The client has a call into Sony as of early this afternoon when I brought it all up, no answer yet. Clients are the ones who gave me the song lineup after I timed all 40 songs (live audience, lots of applause on both ends, bla bla bla), and said, "red book says we can use up to 79 and a half minutes." Yeah, I've heard about waivers and such. I ain't signin' nothin'!

I still don't really understand the time vs. space relationship yet. It is conceptually simple, I know it is, but I'm just not getting it.

[minister]

Originally Posted by Postman

I still don't really understand the time vs. space relationship yet. It is conceptually simple, I know it is, but I'm just not getting it.

Difference between a data CD ROM and how the bytes are counted and an Audio CD. As I said above, 2,048 bytes per block Data, 2352 bytes per block Audio.

[Postman]

I logged on tonight to wrap up this thread and you have already posted the answer. You are correct, the number in Sony/DADC's sheet that frightened me so much apparently refers to yellow and orange book (data), not red book (audio) cdrs. Once that many bytes are encoded with orange book's third layer of error recovery bits, the cdr is full. I don't know why they (Sony DADC) don't specify a time in their spec for pre-mastered cds (red book), maybe because they don't want responsibility for problems with play times longer than the original red book ideal, 74 minutes. I got an email from them that assured me any time up to slightly more than 79 minutes was no problem. (I also wonder why their spec sheet does NOT include DDP files as acceptable input material, but maybe that is not as common now that people like me are expected to master as well as make coffee.) Anyhooo, the gold masters were shipped this afternoon and I'm on to the next project (unless I get a phone call from Sony!!).

Thanks to you, as well as to Greg Reierson and Jon Hodgson on gearslutz, for clearing out my head on the math. I've always known that audio CDs have less error correction than data CDs but I never went through the numbers before, I've never had to until I saw that data limit spec. Before, if I could put xx amount of stuff on a disc without error messages from Toast, that was good enough! I'm glad I went through all this "book larnin'", I've "larned" something, but jeeze I wish the spec sheet were a little more clear so I could just remain a bonehead! That number was the very first spec, ahead of everything else. I made the mistake of believing it.

[minister]

Originally Posted by Postman

...Thanks to you, as well as to Greg Reierson and Jon Hodgson on gearslutz, ...

Hey, Greg is Mpls too, an ME here of around 20 years I think. And that Jon Hodgson is a smart man who knows his digital shizzle.