Mixing speaker cables on bi-wired speakers

This is going to sound like a dumb question.  I have bi-wired speakers and I like the bass from XLO and transparency of Nordost, so I have Nordost on the top posts and XLO on the bottom post for good solid bass.  Has anyone ever mixed speaker cables as I have described?  Is this common or not recommended?  It would seem to me that the Nordost ribbon cable is fast and XLO (XLO Ultra) is slower in comparison, but I cant tell that by listening?  

FWIW, the speakers are EggelstonWorks Rosa

Thoughts?