[frankmcr]

You probably know this but just in case: tiple strings aren't exactly paired, they're arranged in four groups , 2-3-3-2.

Tiples are also notoriously difficult to intonate properly (the middle string in each group of three is a low octave string).

If you don't get an answer here you might try the Mandolin Café forums, they discuss tiples from time to time. Or the Martin forum, Martin made a lot (relatively speaking) of tiples.