Everytime I try to watch a movie in either Dolby Digital 5.1 or DTS 5.1 it always defaults to one of the goofy surround modes like Prologic II or something and I have to manually put it back to plan DD or DTS. I have the default set to just stereo on the 990 but it still picks something different every time. Can I fix this or is it something I just need to put up with?

Also i get a poping sound everytime i switch chapters in a movie, is this normal too?

I have that happen to me to

If you mean by default you have the menu option selected to Stereo, you may want to change that to DD or DD+PLIIx, this assuming you want to watch your movies in surround sound. You also need to use the optical or coax selection for this to work and what I found is that I got more menu selection options if the source was active. i.e. for my cable box, if I was toggling the default surround format while on a non-5.1 enabled feed, the options did not allow for me to choose DD+PLIIx.

If your using your DVD for both movies and CD's, then I suggest you run the output use the CD input for the default to Stereo option and thus use the CD for playing music, then switching to the video for playing movies and your defaults will be different for each. This is what I do as I have my DVD Player driving three source inputs in the 990, DVD, CD, and 7.1 direct, each with their own default settings.

If it typically defaults to Prologic (not other modes), read page 25 of the manual in the grey highlighted box. I wonder if it has anything to do with that.
I constantly have to hit Dolby Modes to get the 990 to flip to Dolby Digital. It does, but the kick of it is, then it's stuck on Dolby Digital. You couldn't even go back to Prologic if you wanted to. Bizarre behavior if you ask me. I've commented about this before. Here’s a thread…
http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/34/t/000598/p/1.html#000013

I don't know if it'll work for you or not, but you might try this: Go into the 990's input menu when you have a DD or DTS disc playing and select "Dolby Digital" or "DTS" as the default mode for that input. "Stereo" as a default is going to be ignored since it doesn't directly relate to these modes.

I am guessing that you have a 7.1 setup, since that's the only way the PLIIx would be an option with a 5.1 source. If that's the case, is there a reason that you prefer straight DD 5.1 or DTS 5.1 to PLIIx (which still does the DD or DTS decoding but then uses PLIIx's matrix decoding to derive rear surrounds from the side surrounds)?

gonk,
i'm not sure if the suggestions were for me or meatag

i tried it out for the heck of it, it was already on the correct default of dolby digital.

regarding the preference of dolby digital, i guess just because it sounds different. for some reason, the center channel is much more pronounced when in Prologic. i also always though DD and DTS had discrete channels for all 5.1 and if i'm missing out on that, that's not cool

It was for meatbag, but you're welcome to it as well.

When applying PLIIx to Dolby Digital, you would still get the discrete 5.1 channels - PLIIx is applied to the surrounds only to generate rear surround data.

Let me clarify some stuff

its a 5.1 setup, im using optical connections for DVD player and cd player (seperate units) and i have the 3.11 firmware (I was told this might fix it)

I tried setting the default while playing a DD or DTS source and it still trys to default to one of the virtual surround modes the next time i try to play that souce again.

Oh, and ive gone through every menu I could find and everything else is setup correctly like the speakers sizes, etc..

On a side note. Any reason my subwoofer would be getting test tones all the way too 120hz when the crossover is set to 60hz on the 990?

There's a reason the subwoofer is getting tones to 120 Hz when it's set to 60.

60 Hz is the nominal -3 dB point for the filter. The signal to the subwoofer is attenuated by the 990* above this frequency at 24 dB per octave. One octave above 60 Hz is 120 Hz, so the signal will be reduced in amplitude by 24 dB. This is just over 200:1 power ratio but to our ears it's somewhere around 4:1 or 5:1 perceived amplitude.

* Per the manual, specifications page

It would be nice to have a filter with an infinite slope. However, this is not possible in the real (analog) world. In addition, as the slope gets steeper it becomes much more difficult to avoid ripple in the frequency response and adverse phase effects. Even with digital signal processing there is a practical limit (processing time, delay for # of samples, etc..)