*** Update ***

Ok so I got my replacement sub in and replaced the bad one and put the new through its paces. It performed flawlessly! I even noticed a difference in music that I'd previously thought sounded fine. The bass sounded tighter and much more accurate. I was truely delighted!!!

I put 'Ironman' back in to reference the LFE that first made me aware of the bad speaker. The scene where Stark launches his demo missile went off without a hitch. No rattling or clanking. Just clean, low bass flowing from the EP800, now that's what I'm talking about! Watch a bit more, come to the scene where he puts the original suit on and marches through the cave. There's a TON of LFE going on in this scene. As he marches along something starts to rattle. At first I couldn't tell if it was a speaker or part of the sound track. I listened closer... by the end of the scene it was unmistakable, the other speaker also has something wrong with it. \:\(

It's not nearly as pronounced as the one I replaced, it made it through scenes the other one couldn't. But it's bad none the less. This is not what I was hoping for. Now my attenion shifts to what could have caused BOTH of my speakers to go bad? Did the problem with my amp allow my something to happen that damaged both speakers? It's about the only conceivable theory in my book. I simply can't imagine any possible way I was sent a unit with not one, not two, but three defective components. Something just ain't right here.

I guess I can replace this speaker too now that the amp is replaced and hopefully not damaging the new speakers. If the next one shows up and this doesn't clear up then I'll be at my witts end. I did discove one thing that I previously didn't even know about. I finally got the Denon to come back up on screen so I could go in and set all the speaker parameters and such. And while I was in there I found a setting called 'Subwoofer Limit'. It has you manually increase the LFE level until your speaker starts to distort and then it sets the limit just below that. I've never had that option set before, and my Cerwin Vega sub never distorted. Is this a setting many of you use? My biggest question is, doesn't the DSP chip in the EP800 control distortion? I didn't think I needed any kind of limiter on the EP800 because I thought it was already safeguarded against problems such as these?

So has anyone else ever had an EP500, 600 or 800 distort during very low frequency emissions? This is very disappointing. I was so ready to have these issue's behind me by now. I guess it's a good thing I never did the Dynomat experiment. I may end up having to send this unit back if I get yet another replacement woofer installed in it and it doesn't clear the problem up.
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My Stuff :

M80's
QS8's
VP150
EP800
Denon 4802
Emotiva XPA-3
Samsung BD-P3600
Sharp 65 Inch Aquos LCD