I just chanced it and tapped into wires until I got it right(lucky did't bread something). I am begining to think their is no solution to this problem. The base still gets cut down when I turn up the stereo. Which mean one of two things. 1. their is another modual somewhere reducing the bass, or 2. the reducing is a built in function in the stock head unit.

Do you guys think the reducer is built into the head unit?(which means I have to go aftermarket) Or should I tear apart my dash to try to tap into a full range sorce in the back of the deck.

this is what I have found with my aurora.. I do not have BOSE though. With the stock headunit at full three bars on volume the bass would be at its maximum. When I would start to turn the volume up above that at all the bass would start to get quieter until you were at nearly full volume then the bass was totally gone. With my now aftermarket pioneer cd player bass is relative to the volume.. as in, it'* linear with the raising of the volume ***. It'* not boosted at low volumes, and it'* not cut off at high volumes. I think the cutting of bass at higher volumes is in the stock cd player. The high pass filters for the front and rear speakers are in the amp I think.

Yes you are probably right, it'* a function of the HU. So either replace it or use some artificial bass boost (ick) Sorry it didn't work out.

if you want any good stereo in your bonneville, you have to completely bypass the bose system