Pressing a CD or Record

With today’s CD-R burners a lot of bands are producing short runs on their computer at a very low cost. However if your popularity and sales warrant it pressing a CD commercially can sometimes be more cost effective. Once the first pressing is made the cost drops for each new thousand your produce thereafter.

The process of pressing a commercial recording is a lot different than that for a home-burnt CD-R! The first thing you need to do is prepare a master.

A CD-R does not make a great master, as the frequency response is only rated as being between 50 and 17,500 Hz while a high quality DAT master is closer to 20,000 Hz on the top side. But even a DAT master is not good enough for pressing.

Today they are making hard disk, as well as tape based digital masters. The Sony PCM 1630 two track digital process has been the mainstay for final CD masters since the 1980s, although it is slowlying being phased out in favor of more modern processes. The process of making a final, high quality digital master must be done by an engineer trained in the process and typically at a cost of about $200 per hour. Part of the mastering process is putting a SMPTE Time Code (that same type of a track used to edit video tapes professionally) along with the audio recording. The recording must also be glitch free.

What they often do is take your DAT tape or analog master and either convert this to the Sony 1610 format or go directly to the 1630 mastering on video tape. A header file with time code and copyright information is made. Then your audio tracks are put in, spaced by more time code. They can also make the master off your CD-R or DAT, but you are responsible for any pops or glitch that comes as a result of the master your provide!

After this process some people request a glass master to demo the final CD. This is an extra cost item, but it allows the producer to see how the finished CD will run and will show any glitches immediately!

After this the final master is struck. In a CD-R a low powered laser melts some globs of chemical dye embedded inside a plastic sandwich. In a commercial CD a high powered laser makes precise pits into a glass master disk. Unlike the CD-R melted globules, which vary in shape and density, the pits in a glass CD masters are very precise. From this glass master a metal mother is made much like that for the vinyl record process. From this metal part a mold is generated to make the final stampers.

A commercial CD is made by melting a plastic-like material between metal parts containing nubs that represent the laser pits in the original disk. These spines create similar pits in the plastic material after it cools and hardens (which are not as precise or small as the original pits made by the laser, but are still far more perfect and uniform in size than the melted globs of CD-R chemical)! The back side of the CD disk is then aluminized like a telescope mirror (again, CD-R uses a less costly chemical process that doesn’t reflect light as brightly as the aluminized backing of a commercial CD). Finally a lacquer surface is put over the back of the disk to seal the aluminized surface. Then a silk-screened label for album title or band name is placed over this lacquer (on your CD-Rs the top side is already silk-screened with the logo from the maker of the CD-R disk, to this you place a paper label which adds weight and bulk to the CD-R, which can even cause damage to some CD payers).

The CD is put into a jewel case with a V card (you may have to pay extra for an under the tray card) and possibly a booklet. All of this is shrink wrapped and boxed.

The result is a CD that is virtually every bit as good as any you buy in the store. One that is easily 5% better than any CD-R and sometimes as much as 20% better. Not every CD-R disk plays in every CD player! Audio disks made on the green CD-R material work the best, but have only a 10 year shelf life (that dye eventually fades and the CD-R becomes unreadable) – compared to the commercial CD which has an indeterminate life (the aluminized backing is sealed against air and could last for decades before tarnishing). How close the CD-R is to the first generation of music determines the final frequency range, as does speed of reproduction, type of chemical disk and accuracy of the laser beam. All of these factors contribute to the degredation in quality of a CD-R music disk. In a commercial CD the only real factor is how good is your original digital master source?

The process for making a vinyl record or cassette tape is even different. Here, they can start with your DAT master or you can even use a CD-R as both vinyl and cassette will not have a 20 – 20,000 spectrum no matter how you cut it!

Most plants, however, still want an analog tape master done at 15 IPS with white fill leader between the songs and test tones at the start of the tape. Generally they want at least 2 minutes of 1 K Hz tone, but would like to see 30 seconds of 100 Hz and 10,000 Hz tone to adjust their playback equipment.

Your master should have a log sheet, detailing the names of each song, their timing and what order these ore found on the tape. It should also identify any test tones.

For cassettes the plant will generally make their own master tape. Either a ¼” tape at 15 IPS or a top quality master cassette. From this they will strike off the other cassettes, which are often done in groups of 12 or 24 on a master machine controlled from the single cassette slave.

Most cassette manufacturing plants use chrome tape (generally BSAF or Fuji) to make their masters. If you are using noise reduction (Dolby C is the most popular) it should have been encoded at the time your made your master cassette or when they duplication plant is making one off your digital or analog master tape.

Dolby works by increasing the high end during recording and then reducing it at playback. When you reduce the high end tape hiss drops. By increasing the high end during recording, the cymbals tend to sound more produced. A lot of people leave Dolby off when playing back their tapes, because the hi hat and ride cymbals seem to have more presence!

Once a tape has been encoded with Dolby you don’t need to do it again. You simply make a straight copy (with Dolby OFF) of your Dolby original. The encoding is automatic.

The speed of duplication can have an effect on the final tape quality. Realtime duplication works best (but costs the most) for music recording. High speed duplications tend to have poor quality on some of the frequencies due to the fast speeds used to duplicate the music.

At the duplication facility they will also stamp your band name and album information on the plastic cassettes using a special machine (a few plants may use paper labels – this is something to consider when choosing a plant to make your cassettes). A V card is put into the case and they are shrink wrapped.

Vinyl records are still popular in some countries and will still get you on the radio in many places. The process is akin to making a CD. First a master lacquer is recorded using a cutting lathe. This is done on a large metal disk coated with soft lacquer. A special needle etches grooves and pits into this laquer disk. After recording this disk is then placed is a special liquid and a metal part is grown on it by passing electricity between the metal inside disk and from across a vat of chemical containing metal particles. (This is the electroplating process, which we described in our article on Gold from last year – growing a metal part a similar process to making a gold plated item.) From this metal part you can either stamp about 3,000 records (a one-step process) or make several mother master disks on metal (the three-step process) from which metal stampers are made. Each stamper is capable of making between 1,000 and 3,000 records.

Like the CD disk, a plastic material is melted by the plates, but instead of little pits, a single groove of varied width containing small etches that machines the audio wave is created on both sides with a paper label embedded in the center during the hot pressing process.

This disk is then cooled, placed in a paper or plastic protective sleeve and then put into a cardboard outer package for 12” albums which is shrink wrapped.

Some companies take a short cut on the shrink wrap process by putting it down the middle of the album, which can cause a warped records. Make sure you get the shrink wrapping that goes along each edge of the LP as unlike cassettes and CDs putting the heat iron at any other place will damage the contents!

Randomly spot check a few of your albums to make sure they are straight. Also make sure the outer track is spaced far in from the edge lip, as the bow of the lip can make some cartridge skip and track wrong! Store all CDs and albums upright to lessen warpage.

If you are expecting to send any CDs or LPs out to radio stations you won’t need to shrink wrap them! This helps reduce your costs a little and by leaving them unsealed you make it easier on the radio stations to open and preview the disk!

When pressing 7” 45s you might want to consider making them with the non-traditional small hole (same size as used for LPs) instead of the old large hole (that was instituted for the juke box machines) as the step down adapters are getting harder and hard to find. We put out several singles with the small hole and never had a bit a problems or negative feedback.

A 45 is still the cheapest demo calling card you can produce – at a cost of around $375 (US) for 500 or $450 for 1000 two songs (“a” and “b” sides).

Some pressing plants handle both CDs, LPs, 45s and Cassettes. Some plants have slip order deals in which you can get a supply of cassettes and CDs or all three items!

The cost for cassettes packages are around $1,000, the LP packages around $1,500 and CD orders around $2000 for 1,000 units each with a one color V or U card cover. Color covers and booklets increase the price, as does the pre-print materials for the color work (which today are done on disk).

Our Music Special continues with these other articles:
Learning Music | Promo Pictures | Booking Agents| Managers | Producers | Pressing CDs
Record Companies | Copyrights | Recording Software | Sound Cards | Guitar and Bass
Multi-Track Recorders | Live Sound Gear | Microphones | Recording Engineer | Bands in Texas
Teen Band: Y@nK | Gigs and Clubs | Music Theory | Radio Airplay

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