Well, Iv'e got a 98' A4 with the concert stereo and bose setup.

Im going to replace the headunit for now. Got it, and all the proper wiring and goodies in the mail:

I just ordered an HU from crutchfeild, with a 20$ off coupon (offer code 3a825)
Head Unit
and got all this for free:
Harness
Dash Kit
Antenna Adapter

Then i remembered i have some two ohm tweeters left over from a component set i robbed the woofers from for my last car... These (just the tweeters)

So i figured i might as well put those in while im at it, then i decided i want to upgrade the rear deck subs and the "woofers" in the front doors also, and just leave the bose amp and see how it sounds.

So i found these for the front doors and These for the rear deck "subs". They aren't exact matches, and may take some modification to fit, but they were like 5, and 11$, respectively. So i figure its worth a shot.

Ill try to document the install and let you know how it sounds when im done. Maybe these two speakers will be reasonable cheap replacements. And 2 ohm tweeters aren't hard to find, nor are the rear door speakers.

All said and done, ive spent about 170$ and im getting a pretty damn nice new HU, and replacing all the speakers except the rear doors, and leaving the bose amp for now. Hopefully this will be a worthwhile budget upgrade... Sure is a change from dropping like 2 grand on the audio in my last car.

 

Can you clarify what you mean by having the Concert headunit with Bose setup? If I'm not mistaken, the headunit is the same regardless if you have Concert or Bose speakers. It's just programmed differently. Did you replace your rear door panels and put speakers in? Or do you have the Bose setup, but the headunit says Concert when you turn it on

I was about 2 minutes away from buying these when I refreshed the page and saw your post: Kenwood KFC-1664S 6-1/2" 3-way car speakers — also fit 6-3/4" openings at Crutchfield.com

I'm not sure how much of a difference it makes, but the Bose headunit is for impedence of 2 ohms where as the Concert headunit is 4 ohms. I'm assuming the rear deck BOSE amp is also 2 ohms and the rear deck CONCERT amp is 4 ohms. I'm not too familiar with audio equipment, so correct me if I'm wrong.

Can you let us know how the install goes in regards to fitment, alignment, bass, loudness, etc. I'm assuming you have the Bose amplifier in the rear.

Also, when do you plan on installing? I was looking forward to installing next weekend

 

I just meant the radio is a "concert" model, and i have bose speakers and amp in the back. When i turn it on it says bose.

I really have no clue how the programming on the stereo works... ive been trying to figure that out. But like THIS thread you sent me via PM says: "- Non-Bose uses the h/u to power the front speakers (using its internal 20w+20w amp) and the rears use the rear lin level out from the h/u and feed the little amplifier attached to the left rear speaker, this amp then powers the two rear speakers.

- Bose uses the front and rear line level outs from the Concert, feed into a Bose amp, have Bose 2-ohm front and rear speakers and a small subwoofer."

I hope to install in the next couple weeks.