There's So Many CD Formats, I Don't Know What To Do!

by Roger Nichols

I can remember when you went into the studio to mix an album for vinyl records. You would mix all of the tracks to sound the way you wanted on the album, and then maybe change a few things for the single that would make it stick out a little better on the radio. Oh, and if you remembered, you would print TV mixes. TV mixes were the ones with the lead vocal left out in case the artist performed the song on television. The vocal would be added live during the taping of the TV show. That was about the size of it. Today, you have to think about the main mixes for your album, primarily for CD release in the United States, as well as the possibility of mixing alternate versions for a myriad of other uses.

One alternate mix version is for European and Japanese markets. Because of the wide spread import problem, the only way to get the Japanese to by the Japanese version of your CD is to include versions of the mixes that aren't available in the United States. They same alternate versions could probably be used for the CD singles that are released in the U.S. The record companies think that people are more likely to buy the single if it contains versions that are different than the album. Sometimes the version of a song that is released as a single and gets tons of airplay is not the same version as the one released on the album. I ran into this particular instance when I bought the Babyface album that contained "When Can I See You Again". The version on the album was just vocal and acoustic guitar. The version played on the radio was only available on the CD single.

Another version that you have to start thinking about is for CD-ROM products. More and more artists are coming out with CD-ROMs containing the album material along with low-res versions of their music videos, interviews with the band, tour information, fan club information, horoscopes of the roadies, and other meaningful data. The audio that is placed on these CD-ROMs may not be the same quality as that of an audio only CD. The sample rate may be 37kHz with 8 bit resolution instead of 44kHz with 16 bit resolution. Sometimes the lower resolution requires that a different mix be used to "get the point across".

There is a product out there called "Rock Rap and Roll" that allows the user to edit together segments of a song in any order he sees fit. When the user plays the song back he can play guitar licks, horn solos, keyboard parts, vocal phrases and a number of other instruments along with the track. Basically the user is jamming along with the band. In the studio, the producer and the artist had to mix a version of the tune without the lead instruments and cut them into four or eight bar segments with pre-determined edit points so that any segment could be connected to any other segment. The lead instruments then had to be edited into one or two bar phrases that could be played by the user pressing a button on the mouse or a key on the keyboard. This sort of product is becoming very popular and is going to require some thought on the part of the artist to come up with mixed material that will work well in this environment.

Colored Books

Phillips and Sony printed the specs for Compact Disc Digital Audio and named it the Red Book. Red Book CDs are 16 bit PCM encoded at 44.1kHz. For now, that is all you need to know about the Red Book. (Actually, if I told you any more, I would have to go look it up, and I'm too lazy to get out of my chair.)

The Yellow Book covers CD-ROM and CD-ROM/XA. Mode 1 tracks are for computer data. Mode 2 tracks are for compressed audio. The XA extension to the Yellow Book spec allows for computer data and audio data to be interleaved in the same track. The important part of the Yellow Book spec, as far as mixing audio for CD-ROM is concerned, is that there are five different stages of audio compression allowed. They are: ADPCM Level A sampled at 37.8kHz 8 bit; ADPCM Level B sampled at 37.8kHz 4 bit; ADPCM Level C sampled at 18.9kHz 4 bit; Digitized 22kHz with 8 bit samples; and Digitized 11kHz with 8 bit samples. There is a wide range of audio quality possibilities for CD-ROM audio, and it would be great if the mixes could be tweaked to sound the best they could under these sub-CD quality conditions.

Just to round out the Rainbow of Books, next came the Green Book which described CD-I, the interactive CD designed for the dedicated player introduced by Phillips. The White Book spec allowed CD-I information to be recorded on CD-ROM/XA discs. This allowed a producer to ship one disc that could be used with Macs, PCs and CD-I players. The Orange Book laid down the laws for CD-MO (magneto-optical) and CD-R. Don't forget the Blue Book. This is the book that the finance companies use to tell you that your car is not worth as much as you thought it was.

Getting back to the original point of all this (as if I could remember the original point this long), CD-ROM applications are going to be an ever increasing market for music software. Making your mixes sound better than the next guy may give you the edge in landing the contract to provide music for the next hit video adventure game. It's something to think about.

Now What

Wow! After a few paragraphs like that, I get Brain Frost, like when you eat ice cream too fast, or stick your nose in a dish of liquid Nitrogen.

I have come up with a great way to cut down on the amount of time it takes to drive long distances. Well, actually it is just a way to make you think that it didn't take much time. A month ago I was driving from Los Angeles to Nashville, a distance of about 2100 miles, while listening to the CDs that I made for my car. I was thinking about mixing records and about how many times you have to hear the same song over and over. You go into the studio about 10 o'clock in the morning and start working on a particular tune. You play it over, and over, and over, and over, and over, and over... well you get the idea. Pretty soon somebody walks in and says that it is midnight and you should start thinking about continuing the next day. You look startled and wonder why the time went by so fast. I guess you go into some sort of hypnotic trance and forget all about time. I went in to the studio one day to work on a Donald Fagen song, and by the time I looked up at the clock, my daughter had gone all the way through high school without me noticing.

Anyway, I thought that if this works in the studio, then it should work on the highway. I was just heading East out of Phoenix and I selected a song I liked on the CD player and pushed the REPEAT button. The song started playing over, and over... The next thing I knew, I was in El Paso. Actually I was lucky enough to not regain coherent though until I had passed beyond El Paso. Where had the time gone? This was great. I pulled off to gas up and was again on my way East. I selected another song and said, "I should be in Dallas before this song ends." I was. It works. I may be on to something. I'll be rich! Oh, yes, I now have 12,000 miles on my CD-R with no signs of wear. Between Me and Steve St. Croix's (do you use an apostrophe-"s" after a silent "x" that looks like it should sound like an "s", or just the apostrophe?) Porsche sitting in the desert, we should have a leg up on the usable life of CD-R discs pretty soon now. I am going to re-calibrate my speedometer to read out in CD sectors/mile. 55 miles per hour works out to be 4909.0909 CD sectors/mile. Or you could look at it like Nashville is 25.9459 CDs away from Los Angeles. Or, if it takes a day and a half for a chicken and a half to lay an egg and a half, how long does it take for a rooster to hatch a hardware store out of a door knob?

I went by a record store yesterday that was advertising a New Years Day sale. All CDs specially priced at $19.95. I bought four CDs before I realized the price was going to drop back to normal after the sale was over. Must have been the Brain Frost. Or maybe its time to check in to the Home For the Digitally Deficient out near Chatsworth.