I am asking this question here because it seems like a very knowledgable group of people here.
Have an HK 635. When speakers are set to small using the set up menu, I get a static in surround speakers. When I run them as large no problems.
It doesn't matter if I use the EZ EQ set up or manual.
Also I have " bright" speakers. If I was to buy another unit I would need a warm sounding pros. how does the 990 sound,

Odd that bass management would generate noise. It sounds like the 635's processing is messing around somewhere (either in the crossover or in the EQ somewhere), but I can't pin down where it could be happening.

I tend to classify the 990 as neutral - not something I'd call warm, but not bright even with the metal dome tweeters I use.