Assume for a moment that one is building an APO solution for acoustic echo cancellation, something that customers and clients both still want, despite the Microsoft philosophy. The capture end of that will have to be an LFX APO. Does that run in the context of the application's process, or is it in the audio engine process? If it's in the application's process, then shouldn't I be able to exploit the loopback recording interface, instead of writing a GFX APO to perform the loopback? -- Tim Roberts, timr@xxxxxxxxx Providenza & Boekelheide, Inc.