Linear arithmetic synthesis: Difference between revisions

Revision as of 23:09, 13 May 2017

Revision as of 18:51, 23 May 2017

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'''Linear Arithmetic synthesis''', or '''LA''' synthesis, is a type of [[sound synthesis]]term invented by the [[Roland Corporation]] when they released their [[Roland D-50|D-50]] synthesizer in 1987. LA synthesis was since used by a number of other Roland equipment, such as the [[MT-32]] [[sound module]] in 1987 and the [[Roland E-20|E-20]] [[synthesizer]] in 1988.

== Overview ==

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LA synthesis combines traditional [[subtractive synthesis]] with [[Pulse-code modulation|PCM]]-based samples.

The term "linear arithmetic" refers to synthesis that is all [[Digital synthesizer|digital]] (linear) and a summing (arithmetic) of sounds. Roland did not use the term ''additive'', as [[additive synthesis]] already refers to a different synthesis method.

This technology first appeared in 1987, in the [[Roland D-50]] synthesizer. At the time, re-synthesizing samplers were very expensive, so Roland set out to produce a machine that would be easy to program, sound realistic, and still sound like a synthesizer. Also, [[Yamaha]] had previously gained world market lead with their [[Yamaha DX7|DX7]] [[frequency modulation synthesis|FM synth]], which excelled at metallic, percussive sounds—something that Roland's synths using subtractive synthesis were less good at.

Roland understood that their subtractive synthesis method had to change. One of the more complex parts of a sound to program is the attack transient, so Roland added a suite of sampled attack transients to subtractive synthesis. As well as the attack transients, Roland added a suite of single-cycle sampled waveforms that could be continuously looped. Sounds could now have three components: An attack, a body made from a subtractive synth sound (saw or pulse wave through a filter) and an "embellishment" of one of many looped samples. (The looped samples also contained a collection of totally synthetic waves derived from additive synthesis, as well as sequences of inharmonic wave cycles. Thus, LA synthesis offered the realistic sounds of a sampler with the control and creativity of a synthesizer.)

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==Similar concepts==

Ensoniq with the [[Ensoniq SQ-80|SQ-80]] hadcalled athe similarsame technique called Cross Wave Synthesis.

Yamaha's [[Yamaha SY77|SY77]], its rack-mount equivalent [[Yamaha TG77|TG77]], and successor SY99 introduced Advanced Wave Memory 2 (AWM2), enabling playback and digital filtering of samples. Notably, these also let AWM2 samples be used as transients to Advanced FM (AFM) synth sounds, as looped oscillators in their own right, or even as modulators of AFM carriers. This, like LA, enabled more realistic modeling of physical instruments, and in combination with FM, new possibilities for synthesis. The SY99 seemed to be the last FM workstation by Yamaha, and the later FM synth [[Yamaha FS1R|FS1R]] did not feature AWM—so SY99 was seemingly the last synth in which AWM and FM could be combined. This was until the [[Yamaha Montage|Montage]] in 2016, which combines a later version of AWM2 with FM-X (an offshoot of the FM engine from FS1R, without the latter's Formant Synthesis) - though without letting samples be used as modulators, as the 77/99 series did.