Some various plugins are not more available...
-Dynamic surround output by enon.biz: a fantastic output plugin forse winamp in which you can manipulate all audio files to surround regulating single volume channels (red and blue), Rolloff factor, Doppler factor and Speed factor;
-qmp3 by QSOUND: a fantastic dsp plugin in which you can manipulate Stereo to 3D and also the ambience and the reverb;
-Amazing reverb 4: a dsp plugin in which you can manipulate LP Allpass, Balance (of the reverb)...;
-Virtuoso by SLAB DSP: a dsp plugin multifunction in which you can manipulate the angulation of loudspeakers (two only or more for stereo to wide), or using headphones only, and regulate the room settings
(loudspeakers and/or listener X and Y position, room lenght and high...;
-Wide reverb: a dsp plugin in which you can manipulate Delay and/or Mix (of the reverb), the L/R reverse Balance effect.