In sound recording, dubbing is the transfer or copying of previously recorded audio material from one medium to another of the same or a different type. It may be done with a machine designed for this purpose, or by connecting two different machines: one to play back and one to record the signal. The purpose of dubbing may be simply to make multiple copies of audio programs, or it may be done to preserve programs on old media which are deteriorating and may otherwise be lost.

One type of dubbing device combines two different storage media, such as an audio cassette deck

Cassette deck

A cassette deck is a type of tape recorder for playing or recording audio compact cassettes. A deck was formerly distinguished from a recorder as being part of a stereo component system, while a recorder had a self-contained power amplifier...

 that incorporates a Compact Disc

Compact Disc

The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...

 recorder. Such a device enables the transfer of audio programs from an obsolete medium to a widely used medium. It may also simply be used to transfer material between two types media which are popular in different settings, so that material originating in one type of environment can be used in another. An example of the later would be the dubbing of a Digital BetaCam videocassette to DVD.

Another type of dubbing device is designed to rapidly produce many copies of a program. It may combine a single playback unit with multiple recording units to simultaneously create two, four, eight, sixteen, or more copies during the playback of a single original program. This type of device can often perform the copying process at many times the standard playback speed. Typical multiplexed

Multiplexing

The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...

 dubbing decks of either analog (cassette

Compact Cassette

The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a magnetic tape sound recording format. It was designed originally for dictation, but improvements in fidelity led the Compact Cassette to supplant the Stereo 8-track cartridge and reel-to-reel...

) or digital (CD) programs can operate at 48 times the standard playback speed, thus producing complete copies of a program in sixty or ninety seconds. Sometimes this high-speed dubbing incurs some loss of quality compared to the best normal (1x) speed dub.

The verb

Verb

A verb, from the Latin verbum meaning word, is a word that in syntax conveys an action , or a state of being . In the usual description of English, the basic form, with or without the particle to, is the infinitive...

 "dub" as used here long predates and is unrelated to the Jamaica

Jamaica

Jamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...

n musical style dub music

Dub music

Dub is a genre of music which grew out of reggae music in the 1960s, and is commonly considered a subgenre, though it has developed to extend beyond the scope of reggae...

; the origin of both words stems from the dubplate

Dubplate

A dubplate is an acetate disc – usually 12, 10, or 7 inches in diameter – used in mastering studios for quality control and test recordings before proceeding with the final master, and subsequent pressing of the record to be mass-produced on vinyl. The "dub" in dubplate is an allusion to...

. It is also different with the term dubbing, which is mostly a type of frottage dance usually found in the Caribbean clubs.

Victor S/8

Some of the earliest dubbings were made by the Victor Talking Machine Co. 'In 1915, Victor developed an acoustical dubbing process to create new masters from pressings where damage had occurred to the originals. Such dubbings are marked with the symbol “s/8” stamped in the inner rim. These are occasionally (but not always) noted in the New York files. Pressings made from these dubbed masters are sonically inferior to the originals.'