I sort of agree with czarivey. There is a lot of snake oil in the cabling business, in my opinion.
Though you have a pair of Cardas, I wouldn't be slavish and get a matching pair, especially if the cost was not affordable.
There are many other cables out there that should do the job.
Of course, you are introducing variables, but why not enjoy the ride?
FWIW, a set of Zu's would not be a very costly way to go. Try them on the low frequency side and then reverse with your Cardas. You might be surprised.
Though you have a pair of Cardas, I wouldn't be slavish and get a matching pair, especially if the cost was not affordable.
There are many other cables out there that should do the job.
Of course, you are introducing variables, but why not enjoy the ride?
FWIW, a set of Zu's would not be a very costly way to go. Try them on the low frequency side and then reverse with your Cardas. You might be surprised.