I run M180s into an Athena, and polarity is ok all the way through. I checked it using the pink noise files here:
http://www.eminent-tech.com/music/multimediatest.html
Look at the ones called "pink noise monaural" and "pink noise reverse polarity" - you can use them to verify what your phase situation is like.
http://www.eminent-tech.com/music/multimediatest.html
Look at the ones called "pink noise monaural" and "pink noise reverse polarity" - you can use them to verify what your phase situation is like.