I had a similar problem with mine. Mid range though. It does sound like the same thing.
There was a loose connection/crimp at the back of the plastic basket that separates the woofers and mids.
After crimping the connection and replacing the mid range I've had no issues.
At the time I was worried it might have also been related to my receiver and I purchased an amp, just in case.
Not that it matters but I figured the receiver cost $1000 and the speakers $1500 so a $1200 amp seemed like inexpensive insurance(that's how I justified it with the wife).
