Sample-based synthesis: Difference between revisions

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{{Unreferenced|date=December 2009}}

'''Sample-based synthesis''' is a form of audio synthesis that can be contrasted to either [[subtractive synthesis]] or [[additive synthesis]]. The principal difference with sample-based synthesis is that the seed waveforms are [[sample (signal)|sample]]d sounds or instruments instead of fundamental waveforms such as [[sine]] and [[saw wave]]s used in other types of synthesis.

==History==

Before digital recording became practical, instruments such as the [[Chromatic_phonogene|phonogene]] (1950s) and the [[Mellotron]] (1960s) used analog tape decks to play back sampled sounds.

When sample-based synthesis was first developed, most affordable consumer synthesizers could not record arbitrary samples, but instead formed timbres by combining pre-recorded samples from [[Read-only memory|ROM]] before routing the result through [[analog (signal)|analog]] or [[Digital data|digital]] [[electronic filter|filters]]. These synthesizers and their more complex descendants are often referred to as ROMplers.

Sample-based instruments have been used since the Computer Music Melodian, the CMI Fairlight and the NED Synclavier. These instruments were way ahead of their time and were correspondingly expensive. The first recording using a sampling synthesizer was Stevie Wonder's "Secret Life of Plants" (1976) which used the Melodian to create complex melodies and rhythms from sampled sounds from nature. The first tune Wonder recorded was "The First Garden" where he used a sampled bird chirp as the lead sound in the song. More affordable sample-based synthesizers available for the masses with the introduction of the [[Roland D-50]] and the [[Korg M1]], which surfaced in the late eighties. The M1 also introduced the "workstation" concept.

The concept has made it into [[sound card]]s for the [[Multimediamultimedia PC]], under the (incorrect) name of '"wavetable synthesis'".

==Advantages of sample-based synthesis==

Sample-based synthesis'The principal advantage of sample-based synthesis over other methods of digital synthesis such as [[physical modelling synthesis]] or additive synthesis is that processing power requirements are much lower. This is because most of the nuances of the sound models are contained in the pre-recordedprerecorded samples rather than calculated in real-timerealtime.

In a contrast to analog synthesizers, the circuitry does not have to be duplicated to allow more voices to be played at once. Therefore the [[polyphony]] of sample-based machines is generally a lot higher. A downside is, however, that in order to include more detail, multiple samples might need to be played back at once (a trumpet might include a breath noise, a growl, and a looping soundwave used for continuous play). This reduces the polyphony again, as sample-based synthesizers rate their polyphony based on the number of multi-samples that can be played back simultaneously.

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For sample-based models of instruments like the [[Rhodes piano]], this multisampling is very important. The timbre of the Rhodes changes drastically from left to right on the keyboard, and it varies greatly depending on the force with which the key is struck. The lower registers "bark", while the higher range has a more bell-like sound. The bark will be more distinct if the keys are struck with force. For the model to be sufficiently expressive, it is therefore necessary that multisamples be made across both pitch and force of playing.

==History==

Before digital recording became practical, instruments such as the [[Chromatic_phonogene|phonogene]] (1950s) and the [[Mellotron]] (1960s) used analog tape decks to play back sampled sounds.

When sample-based synthesis was first developed, most affordable consumer synthesizers could not record arbitrary samples, but instead formed timbres by combining pre-recorded samples from [[Read-only memory|ROM]] before routing the result through [[analog (signal)|analog]] or [[Digital data|digital]] [[electronic filter|filters]]. These synthesizers and their more complex descendants are often referred to as ROMplers.

Sample-based instruments have been used since the Computer Music Melodian, the CMI Fairlight and the NED Synclavier. These instruments were way ahead of their time and were correspondingly expensive. The first recording using a sampling synthesizer was Stevie Wonder's "Secret Life of Plants" (1976) which used the Melodian to create complex melodies and rhythms from sampled sounds from nature. The first tune Wonder recorded was "The First Garden" where he used a sampled bird chirp as the lead sound in the song. More affordable sample-based synthesizers available for the masses with the introduction of the [[Roland D-50]] and the [[Korg M1]], which surfaced in the late eighties. The M1 also introduced the "workstation" concept.

The concept has made it into [[sound card]]s for the [[Multimedia PC]], under the (incorrect) name of 'wavetable synthesis'.

==Sampling synthesizers==