I'm not certain I understand the meaning of "have his echo cancellation operate globally over all audio producers and consumers" but if your desire is to be able to cancel the final post-mix signal, you can utilize the loopback feature. Look at the new IAudioClient interface and the AUDCLNT_STREAMFLAGS_LOOPBACK flag. Frank Yerrace Microsoft Corporation This posting is provided "AS IS" with no warranties, and confers no rights. ________________________________ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Roberts Sent: Thursday, September 28, 2006 4:40 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Vista Audio Architecture Hakon Strande wrote: All legacy driver models should continue to work for basic streaming in most cases but AEC and Mic Array processing are application graph DMO effects in Vista (and hosted by the RTC API as well) and does not belong in the driver layer in our vision of Windows and our desire to enable more powerful and flexible Windows application experiences going forward. I understand your goal here, but how does this philosophy reconcile with a client's quite reasonable desire to have his echo cancellation operate globally over all audio producers and consumers? It's not clear to me that an application-centric focus, using DMO effects in an app graph, can provide the same end-to-end control that one has in XP. -- Tim Roberts, timr@xxxxxxxxx<mailto:timr@xxxxxxxxx> Providenza & Boekelheide, Inc.