Sorry for the late reply, I've had an incredibly busy past couple of days.
Mshenay- I normally just use iTunes, although I recently installed foobar2000.
I have the Modi set at 24bit 96hz like you said, with all enhancements disabled. In the "Realtek Audio Manager" the default setting was 16bit 44.1khz and I changed it to 24bit 96khz. I already had playback set to 24bit 96khz in iTunes and I have it set to "play audio using windows audio session"
elwappo99- As far as I know, all equalizers are off. The distortion seems to be in both cups, and is most prevalent in the lower-mid frequencies, especially in parts with electric guitar (everything seems to be muddled together and theres a very slight crackling). At first I thought it might just be the album I was listening to (Ghost Reveries (lossless cd rip) by Opeth) but it is happening across all of my rock and metal, and in songs which my 325is' play with no distortion whatsoever. I've also wondered if there is a possibility that my Mad Dogs have somehow come "un-tuned" or I've damaged them or something, but I've always taken good care of them.
One other thing I should mention is that I broke the detachable 3.5mm cable that came with the Mad Dogs and I'm using the stock fostex cable. I've heard people say that the cable itself is low quality, and I remember that when I would alternate between the two cables before I could tell that the fostex cable was much darker sounding. Is it possible that the distortion I'm hearing is because of the cable itself?