Sample-based synthesis is a form of audio synthesis that can be similar in structure to either subtractive synthesis or additive synthesis. The principal difference with sample-based synthesis is that the seed waveforms are sampled sounds or instruments instead of fundamental waveforms such as the saw waves of subtractive synthesis or the sine waves of additive synthesis.

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 ROM before routing the result through analog or digital filters. These synthesizers and their more complex descendants are often referred to as ROMplers.

A more flexible design allowing the user to record arbitrary waveforms to form a sound's basic timbre is called a sampler. Early samplers were very expensive, and typically had low sample rates and bit depth, resulting in grainy and aliased sound. Since the mid 1990s, however, samplers have featured specifications at least as good as CDss. By the late 1990s, the huge increases in computer processor speed permitted the widespread development of software synthesizers and software samplers. The vast storage capacity of modern computers was ideally suited to sample-based synthesis, and many samplers have thus migrated to software implementations or been superseded by new software samplers.

See also: sampler