Originally Posted by Audiophile2k
Based on this, you are running the sub WAY hot. If setup set it at the minimum volume it could, it is likely that the correct setting would have been even lower, then you've added 14db on top of that...then you are testing it with high volume test tones (in another comment you said you were 7db over reference, meaning the sub was at least 21db over reference). Simply put, more than likely you are pushing either the amp or the driver past their limit.
+1 21db over reference (probably more) is quite a bit more than you can expect from a single sealed 15.
You need to turn down the amp and re-run audyssey, rinse and repeat until it sets the LFE at a higher number than -12. Right now it is out of it's range of adjustability. Once you get a number like -10 or -9 you within Audyssey's range and you can then add 6db to that at most. If you like running 14db+ hot you need a lot more subs.
7db over reference is also way past the point where those pioneer mains start sounding bad. Keep the whole setup below -6dbrl and it will sound much better.