iTunes, iCloud, & DRM incompatibility

Some recent downloads from the iTunes Store of music produced in the last two years will activate the Audyssey program and others do not. Is there anyway to determine which will work with Audyssey and which will not before they are purchased and downloaded? In another answer you mention older DRM files are not compatible with Audyssey. Since most of my music is from CD's produced in the 70's & 80's, is there a way to overcome this limitation? Are there media players that overcome any of these limitations by offering different file types compatible with Audyssey?