2004 Trailblazer Upgrade To Navigation

[bkpickens]

I have a 2004 Chevy TrailBlazer with LT option 1 that includes a non bose in dash 6 disc cd changer with steering wheel controls and onstar. The unit has always sounded like the radio is down in a barrel even if the bass is turned all the way down on the custom setting. Does anyone have any suggestions on what could be done to make factory head unit sound better without spending my childs college fund?

 

I have thought about upgrading to touchscreen navigation factory radio. There is a 15800000 TNR on ebay currently that is suppose to be for a non lux non bose system. I have no idea if my TB is equipped with bose or not. There is no y91 or y92 option on the glove box sticker. I called the dealer and all they could tell me was that the current radio is non bose. Can an upgrade be made to a nav radio if the TrailBlazer doesnt have a bose amp in it at all without changing speakers and everything? Also does anyone know where the factory amp is located in the vehicle?