DLS Synthesizer

Data that is not already in the form of a wave—a MIDI note, for example—has to be converted to a wave form before it can be played by the sound card. This conversion is done by a synthesizer.

Although DirectX Audio supports basic MIDI synthesis on some operating systems, most applications use a synthesizer that implements the Downloadable Sounds (DLS) Level 2 standard. In the absence of a suitable hardware synthesizer, the Microsoft software synthesizer is used.

The synthesizer produces sounds based on wave samples and is capable of producing highly sophisticated musical timbres as well as any other kind of sound.

Note   The DLS Level 1 synthesizer used with the DirectX 7 interfaces contains reverbation capabilities, which are on by default. The Waves TrueVerb reverberation technology is licensed to Microsoft Corporation as the SimpleVerb implementation.

The DLS Level 2 synthesizer used with the DirectX 8.0 interfaces does not contain built-in reverberation capabilities. Reverberation is instead implemented as a DMO. Waves MaxxVerb is licenced to Microsoft Corporation for this purpose.