Audio Emulation

The DSP is an additional processor used by the Wii/GCN to process sound. Dolphin has two ways to emulate the DSP.

• HLE (High Level Emulation): HLE works by using a DSP engine created by the developers from studying the real DSP. It is not perfect, and is notorious for causing garbled sounds, choppy audio, skipped instrumentation, and desyncs. But DSP HLE is very fast with almost no overhead and does not require any additional files.
  • DSP HLE is improving on a regular basis, and versions 3.5-78 introduced fixes for many GameCube games' HLE audio, and 3.5-1154 brought those same improvements to Wii games and refined them further. As of 3.5-1154 DSP HLE is very good.
• LLE (Low Level Emulation): LLE uses DSP ROM files to emulate the DSP's hardware behavior. This unfortunately requires a lot more processing power, but provides perfect sound in nearly all games. As of 3.5-1031 Dolphin includes a developer-created DSP ROM which allows DSP LLE to function without dumping LLE files from a console. Its compatibility is very good, but it will have errors that a DSP ROM from a console does not have.

For the absolute best audio, DSP ROM files should be dumped from a console. There are several ways to dump DSP files, but the easiest method is to use DSPSpy on a Wii with the Homebrew Channel installed. For details on other methods to dump DSP files, go to the forum thread.