Can't say for the Candela. The Mono Extreme SE's were every bit of 400 hrs if not longer to really get to where they finally settled in. Decent out of the box for 50-60 hrs, then Jekyll and Hyde until about 250-300 hrs. After that, they smoothed out and just kept getting progressively better - smoother all through, better imaging, gutsier-tighter bass, etc.
Bryan