I've been experimenting with my setup a lot lately - not changing out any components, but moving it around my room, and trying out different placement of the various components.

I've noticed that at times, the setup can sound very harsh and unpleasing in the high frequencies; it's a grating, very annoying feel. At other times, it sounds incredibly smooth and enjoyable; it's so relaxing I just bliss out.

It seems to sound different every time I turn on the system, even if I haven't moved things or changed the music I'm listening to. All I know is that it's a high frequency thing (including high mids - think of a high trumpet, guitar lead, soprano, bells, that sort of thing.)

So what's going on?? What is causing my rig to sound awesome on some occasions, and crappy on others? Is it all in my head, or is it something else?

My speakers are Magnepan 1.6qr, powered by an integrated amp (Pathos Logos), fed by a Benchmark DAC1. Speaker cables are Speltz anticables, bi-wired.

Any clues? Is this all a matter of room placement? I've got wood floors and a fair amout of window area, but that doesn't explain why my sound is so well-tamed at some times, while harsh at others.

Or could it be a problem with my interconnects? Should I be arranging my interconnects a certain way, to keep them away from the power cables, or from each other?

Any help is appreciated.