Scooter996: I posted a response to your same inquiry over at NOR. Please check it out. There is also another older thread over there on this subject. Try the search feature. I'm not sure my issue is the same as yours, but I'll share my experience. This will be long, so anyone who gets bored, I fully understand if you stop right about now!
I'm one of those folks they call "audiophiles" which means I get way too involved in trying to make my home stereo, home theatre or car sound as natural as possible. I had high expectations for the Bose system in my Armada but was instantly severely disappointed.
The way I set up a system requires a few tools. You will probably not have the equipment. It is not expensive. If you want to do your own setup, whether it is for your Armada, your home stereo or a multi-channel home theatre, the whole setup is well under a hundred bucks.
If your problem is the same as mine was, I will share with you what the tests showed and maybe this will help. It might keep you from springing for the test stuff or paying an audio shop to do the testing for you.
You have to be objective, because your ears will fool you. What you need is a test CD with a lot of different, closely spaced tones ranging from the lowest bass, about 20 hz, to the highest treble, about 20,000 hz. Each tone is a little higher in pitch than the one before it.
I use the Rives 2 test CD for that. No product plug intended. There are other good ones too. But the CD is pretty cheap. It has 31 frequency tracks. It is $21. Here is the link for anyone who wants to do their own testing:
http://www.rivesaudio.com/shoppingcart/index.htm?512.htm&1
You need an inexpensive sound level meter to measure the volume of sound coming out of the system when you play the CD. You can get one from Radio Shack for about $40 bucks. The Rives CD has a separate set of tracks calibrated just to use with the Radio Shack unit.
What my ears were telling me is that the bass was "muddy." it was making the midrange and treble distorted and unnatural. Voices in particular did not sound right. No amount of fiddling with the mid and treble controls sounded right, so out came the meter and CD.
Here is what I found on my system. The bass was horribly over emphasized. I mean bass output was too loud, totally off the scale compared to midrange and treble.
The good news is that Bose got the midrange and treble right. Very nice, flat, linear. Really quite outstanding for a car or truck. To do this testing right, you want to set your meter on a small camera tripod if you have one (it attaches just like a 35 mm camera) and set it up on the center console with the meter up at about the height of your ears.
Leaving the mid and treble controls on "0" worked best for my truck. Get ready for what worked best for the bass - turn that sucker all the way down! I mean turn it to either "-4" or "-5". In that position the bass finally got back down into a range that was not off the meter, which had been the case. So, in my truck, the bass was still every bit as strong as it should have been at "0" when turned all the way down.
With those settings, I then played a broad range of different music and found the bass to be very powerful and the midrange and treble were clear and undistorted.
In this setting the bass is STILL a little over emphasized, especially in the mid-bass, but it sounds very good.
But, this is what would be called trying for a completely flat frequency response curve. Most people have shown a liking for a little bass emphasis and a little emphasis on the top end. Sort of a curve that gradually slopes down from left to right, with a little curve back up on the far right, with deep bass volume on the far left and high treble on the far right, if that makes sense, like a shallow "U" if you drew it out on graph paper.
To get that effect, the bass goes on "-4", leave the midrange on "0" and put the treble on "+1." If your system has the same problems mine did, give that a try.
I realize that the radio head unit was subject to a TSB and if you had yours replaced or have an '05, I don't know if the equalization problem was addressed. If it was, then your meter readings (if you chose to do that) might be totally different.
BTW, for those of you who have Apple Ipods, try using the above settings, and set the Ipod's internal equalization for "Loudness Compensation." Mine works best with moving the bass to "-5" when playing through the Ipod. Give it a try and see what you think.