2003 Chevrolet Trailblazer car audio (bose system)

Every radio will sound different in different vehicles. Chrysler only has a few radio models, then they use different remote amplifiers to condition the tone response for a specific body style. GM does that by having dozens of different radio model numbers that all look the same but won't sound the same in any one vehicle. You might have a radio that was swapped out by the dealer before you bought the truck. That used to be real common to accommodate a potential buyer who wanted the radio model from a different vehicle.

All Chrysler radios put out speaker-level audio and they all can be used with or without a remote amp, but radios matched in a system that uses an amp don't put out much bass. It is made up in those amps. If you use a low-end radio in a car with an amp, you'll have way too much bass unless you turn it way down. Most people hate being bounced around, and their neighbors sure don't appreciate the rudeness either, so you need to use the right radio. If you put the high-end radio in a car with no amp, there won't be enough bass. It will sound tinny, and just start to sound okay if you turn the bass way up.

Again, Chrysler does that tone-matching to the body shape with remote amps. GM does it with radio models. You might start by checking with your dealer's parts department to see if you had the right radio, then with your salesman to see if the radio had been switched. If it was, a mechanic would have done the work, and of course he wants to be paid, so the New-Car Sales Department would have generated a repair order and they would have paid the bill, (transferred dollars to the service department). There will be a folder with a copy of every piece of paperwork generated for your vehicle, so if the radio was switched, anyone will be able to determine that. GM radios normally sound pretty good, so unless you plan on playing "music" for everyone you think will be impressed with the thumping noise, you shouldn't have to replace speakers or the radio.