So far I've seen the Convolverwrapper in the DSP-window of jrmediacenter. It was just a case of (I think):
1) Download/install DirectX host in the plugin section
2) Play audio material
3) Enter player/options/dsp console
And there it is. But I do not yet know whether it works for video or audio only.
BTW, it also shows up in Console, but it seemed to miss the appropriate graphical representation for being setup inside the console. But this might have been due to user error as well. All I know is that Console is an expensive - and probably good way of routing the digital signal between various in'n outs and plugins. So it seems like a good approach. A solution where the convolution is linked to the output device seems more robust than one where it's linked to the input device/player.