I posted this in the audyssey thread, but realized it could be important as a stand alone so it doesn't get buried and is seen by people that aren't 'experts' so they can avoid potential damage to their sub. I am an audyssey fan and hope to have a response from them soon on how best to remedy this:
Have some bad news to report about Audyssey's sub management.
Background: have a HRS 12 Sunfire 1000watt sub thats rated 18hz-100hz. I noticed some 'rattle' like sub distortion during 'the impossible' tsunami sequence. My sub is set to 3 out of 10 on the gain and the audyssey trim applied is -0.5db.
I contacted the sub company and we've been troubleshooting for the past few days. What we found was startling. The 'distortion' only happened in the 10-15hz sound spectrum. With audyssey off, there was no distortion at all during the bass sweeps. With it on, the rattling/gurgle was back. The technician re did the audyssey setup and the 'distortion' came back in the same range. Turns out Audyssey is boosting the subsonic 20hz region significantly.
The 'distortion' wasn't distortion at all either, it was the spider coil slamming into the cone and even just seconds of this type of abuse can damage my expensive subwoofer.
I've written to Audyssey and am waiting on a response on how I can enjoy Audyssey room correction in a way that doesn't damage or distort my subwoofer.