From reader Ed A:

Congratulations, Ed! You are the first person to notice our covert attempt to dominate the world through pronunciation control. We'll be more subtle in our next campaign...

We haven't been able to locate a dictionary that contains "multitimbral," so we can't verify. Our guess is that the editor of the tome in question is not hip enough to browse Sweetwater's site, and therefore didn't know the correct pronunciation.

In our experience, common usage among musicians is "multi TAM bral." For the definitive answer, we asked inSync's editor, Mitch Gallagher (a well-known pronunciaphile). His reply?