First let me say that it's definitely not the CD player. I owned Cambridge D500 SE in the past, and the one thing they were not was lightweight or thin.
Yes, I would agree with the speaker assertion. One other thing before giving up on the Triangles, is to try another speaker cable. Triangles are kind of sensitive to becoming thin and/or shrill, and AudioQuest speaker cables will definitely not help in that area. Although, I am kind of surprised, like the CD player, the rest of your system, apart from the speaker cable, is definitely on the rich side.