FJ i set the Polk tweeter -3 cause they was too loud and try to add a pair of 6.9 to get more mid and mid bass on rear, that make sense to you?
Actually, it doesn't make sense at all. The SRs can deliver prodigious midbass in the right environment, meaning deadened and sealed doors. So much so, that one can easily see how the speakers can be used without a sub. At moderate volumes, they'll extend down to (an articulated) ~60Hz, although I cross over higher. The SRs are also capable of projecting a stable, 3-dimensional image, which is compromised by the addition of the rear speakers, not to mention the blurring of the system's focus and a decrease in transparency. Essentially, you're giving up most of what you paid for.
What does make sense is your configuring the crossovers at -3dB. Personally, I found the speakers to sound unbearably bright even at that setting, and this comes from someone who prefers a vivid, upfront presentation. This is why I found it puzzling that you referred to the sound as "warm."
Please take this in the best way possible, as it's not my intention to insult you. Having read some of your other threads, it's brutally obvious that you're challenged when it comes to system configuration, setup and tuning. You've chosen excellent equipment, yet the user's expectations and the install don't seem to match the capabilities of the gear. I guess I'm trying to say that you could get MUCH more out of your system as it sits.
I'd be happy to give you a hand, if I can, but there has to be more info. Pics would be great. Are you still using a 9886? If so, did you opt for the Imprint module?
Here's a brief review of the SR6500. Perhaps it can be of help:
http://www.caraudio-forum.com/forum/index.php?/topic/1436-polk-sr6500-component-speakers/