st5150, since DirectX audio plug-ins aren't stand-alone applications, they need to be run from within a so-called DirectX "host application".
Invariably, these DX hosts are pro-audio apps like Syntrillium Cool Edit Pro, Cakewalk Pro Audio, Sonic Foundry Sound Forge, Steinberg Cubase, and so on.
Hence, the utility of Adapt-X for Winamp. Specific plug-in/host compatibility is always a potential issue, but naturally that's true for any software. Check the following link for more info.
The DirectX Files - X-Defined:
http://www.thedirectxfiles.com/xdefined.htm
DirectX 8.0 (and above) actually has a
primitive built-in parametric EQ (of which multiple instances can be run), along with a number of other effects, but these only support 16-bit processing resolution. Still, I suppose it's a convenient introduction to working with parametric (versus graphic) equalization. Just don't expect any slick GUI, LOL.
TravelLite