Yup. Sounds like you're not getting a signal somewhere around 63Hz or above...or there's a hole in the signal.
Have you tested just one speaker at a time? A crossover or driver problem would likely only occur in one speaker or the other. If they're both responding the same, then I believe you need to look upstream.
Have you tested just one speaker at a time? A crossover or driver problem would likely only occur in one speaker or the other. If they're both responding the same, then I believe you need to look upstream.

