Now I have only had my unit for about 2 weeks and in that time have only had a chance to watch one movie with any serious attention. What I have been noticing is the unit seems to "mumble" dialogue or other noises when there is no obvious soundtrack noises or other actors speaking on the tv. It's almost like it's out of phase but it's beginning to be a real big distraction.

Has anyone else experienced this? It could just be me and my set-up but I haven't used any drugs in years so that's not that either.

Thanks for any help.

I'm not quite sure what's going on here - the thing that it most reminds me of is the occasional interference I pick up on my house electrical service from a ham radio operator down the street - mumbling speech that my PC speakers will play sometimes and that has on a couple of occasions cropped up in the main system. Is your sub on a separate circuit from your main system? If so, could it be getting some noise from other devices (refrigerator, for example) that are on that circuit with it?

Two other things to consider trying...

How do you have your sub level adjusted? If you have the gain on the plate amp turned way up and your 990's sub trim down, you may want to turn the sub's amp down some and tweak the 990's trim (I've had a two-channel Parasound amp that didn't like being run with the gain controls all the way up, so I've tended to set my sub's amp at no more than half of its max).

How do you have your sub's crossover set up? If it's set to something less than the highest position of 180Hz (or simply bypassed, my preference), there may be something odd going on there with the sub's slope of the sub's crossover and the slope of the 990's crossover. It's quite a bit less likely than my first thought, but worth taking a look at...