DAT vs. MiniDisc: which is better for us?
MiniDiscs are roughly 2.75" square, they run for 75 minutes and were first introduced in 1992. SONY claims that their magneto-optical technology, which allows the disc to be erased and rewritten, means that discs can be rerecorded over a million times, though the discs are likely to have errors before then. The developers of the MD, SONY claims that the information should be safe for 30 years, as the discs are protected against magnetism and normal heat. Another advantage to MiniDiscs is that they can be accessed just like a CD player, instantly jumping to a given track, which you can label electronically.
Developed by SONY and Phillips in the mid-80s, DAT records up to 120 minutes of uninterrupted music on a tape which is 2/3 the size of a cassette. The tape speed is much faster than a regular cassette player/recorder (one can rewind 30 minutes of music in 10-25 seconds). Another DAT advantage over analog tape, the recorders have the ability to put a digital mark anywhere on the tape so that you can access samples more quickly, though not as easily as a MiniDisc or CD. DAT's greatest disadvantage is that it is magnetic tape, much like the tape in a video, which can stretch over repeated use and can be severely damaged by heat and magnetic fields.
DAT recorders have analog inputs and outputs (i/o) like on a regular tape player; they also have digital i/o. This means that they can transfer digital information directly to another digital recorder, without converting it to analog first. As there is no conversion, the copies can be theoretically perfect, like a "clone". This is where they out-maneuver the competition.
MiniDiscs use a compression scheme to fit their 74 minutes of recorded sound into the relatively small memory available on the disc, reducing the data down in a ratio of 6:1. Here is where the problem with MD arises, though for most users it wouldn't be very noticable. MDs don't record to other MDs very well, as they compress and decompress the information each time, much like copying a photocopy. In so doing, small "artifacts" are made (tiny amounts of noise), which get exaggerated with each subsequent dub. For most people in our business, transfer from the MD would be to another medium, such as a computer hard drive for editing, or to audio cassette, as so few people have MiniDisc players. Because of the compression, music purists and audiophiles may hear the difference between a MiniDisc and a DAT or CD recording, but for spoken word, most people cannot perceive the difference. Though the quality of DAT is higher, it is balanced by the MD's ease of use.
There is one other hazard to MiniDisc I haven't mentioned. When you get your material to the stage where you want to have it mass-produced, and multiple copies made on audio cassette, you may run into a snag. The company who duplicates your recording will probably insist that you bring them your material on DAT, as it is the industry standard, and unlike MiniDisc, uncompressed. Gillian Lane-Plescia gets around this by borrowing a DAT from a friend to record a master tape; you might not have that advantage.
Many theatre sound people have adopted the MiniDisc format, as it can be cued up to the millisecond, while DAT has a lag time. If you work in a university theatre department or closely with a professional theatre, talk with the person in charge of sound. They may already have MiniDisc editing and recording equipment, and have some sound advice for you.