I've tried every conceivable setting, but nothing solves the rattling when listening to tunes with deep bass. The speaker is right behind my head so I hone in on this every time.

Is it possible the speaker blew out? If so, is this covered under warranty?

One thing that rattled like crazy was the rear door ashtrays. That was only half the problem. Sounds like the big rattle is coming from the right rear quadrant. Now to go to the dealer and have them find that DAMN rattle!!!

The little door covering my subwoofer would rattle when challenged by ultra-low and loud tones...so I wedged a cloth into the door to stop the rattle...it worked but I'm thinking of making a cutout in the door and putting in a speaker screen / vent to let the sound energy out easier than having it slam against the little door...probably wouldn't work, but is something to do.

There is still rattling going on, I thinks it could be some wiring running under the rear deck. Havent had a chance to really take a look at it but it's one of my priorities after I pass my CFP exam!

I actually took the subwoofer door off. I don't know if it helps the bass, but it solved the rattle.

taking the door off may reduce the effective amount of bass. The subwoofer "cavern" is used to increase the intensity. Ever play something with tons of bass and notice that your car's butt will wiggle? As with most Bose systems, the subwoofer really adds a lot to the effective music feel at your ears up front, but ANYTHING in the trunk or the doors will tend to rattle.

My suggestion: open the door that rattles and listen for the noise while holding the door steady. If you still hear it, bad speaker. If it happens when you let go of the door, you may have a loose screw...in the door.

If it is a bad speaker, I would say it should be covered under warranty, as the Bose amp is supposed to be matched to the speakers and includes a filter to shape (rather than clip) any sound spikes that would damage the speakers. The idea with Bose is that you can play almost anything musical at full volume as long as you like and it shouldn't damage the sepakers one bit (can't say the same for your ears).

I do think that either Audi's mountings for the speakers, or perhaps (as has been suggested already) internal car components are rattled loose by the vibration the Bose speakers make.

I've got some rattles and buzzes on low bassy notes at or near full volume, although dropping about 4 or 5 notches from full blast usually cures them, so most of the time it's not a problem (I'd like to be able to hear in 6 months time, so I keep it down a bit!).<ul><li><a href="http://www.bose.com/products/auto/tech-teens.html">BOSE website</a></li></ul>

and they said that the speakers were performing to spec. I think it may be some components inside the rear doors that are creating the "buzz", like some errant wiring harness tape or even an inspection sticker.

seemed to be a blown speaker on her A4 and it was replaced.

Your head unit is programmed properly for Bose isn't it? Make sure it displays BOSE briefly in the display when you switch it on.

Also check that it's set up correctly for A6 (Sedan I assume), although this may be something you need your dealer's techs to check. The reasoning here is that the same head units appear in a number of platforms with differing speaker layouts and wattage - there must be some kind of setup that tells the head what it's connected to.

I had a problem with my A4's (non-Bose) Concert where the sound quality was distorted and broke up on bassy notes, but the techs could find nothing wrong. Playing with buttons 1-6 while powering up gives various diag displays - these were different to an identical A4, although I was told categorically that "All Concert head units are identical". I suspected a misconfigured head, although the techs thought it was a faulty speaker or possibly head. They swapped it out anyway (I made a lot of noise myself over it to get them to), and the new one gave the same diag displays as the 'reference' A4 and the problem went away.

BTW, this is for 98.5 UK model year (the old Concert units), but I guess that the newer heads are programmed in the same way.

Good luck!

Something is rattling in the car from the somewhat meager low fequency output those little drivers create which don't really qualify as subwoofers. Blown speakers "pop" because the spider and cone have gotten somewhat "disconnected" from each other. Speakers with fried voice coils usually do nothing. You might get a hiss at best.

Given that, you need to chase the rattle around the car and find something to dampen it. Some folks here have offered creative suggestions. Hopefully, you don't have some wiring hanging in the wrong place like I did in my 1989 Ford Taurus SHO. Loved the motor in that car and you got to hear it alot because I couldn't fully crank my tunes up.

Good luck.