Yes audio is still problematic with DSLR’s, others may have better suggestions but it sounds like an attenuator (also known as a pad) may help with the 7D, it is usually used when taking a feed from a mixing desk, it’s avoids distortion. It is cumbersome though.
I’ve now changed my mind from an earlier post where I said the H4N zoom (separate recorder) was problematic. It records beautiful sound and is quick to download and it’s rarely a problem syncing audio in post. But, despite its good reputation, I have had some problems syncing with FCP X. If you can afford plural eyes it ceases to become an issue.
John Doggett-Williams
http://www.fineeyeproductions.com