I want to replace the stock speakers in my A3 with the base Concert stereo, but I'd like to know the parameters of it first.

1. Can someone provide a list and specs (size, wattage, location, etc.) of all speakers in the base Concert stereo?

2. Also, specs of the headunit (watts/channel, etc.)? Pre-amps?

3. Are there crossovers in this system? How are they configured?

I apologize if this info is available, but I couldn't seem to find any comprehensive details.

<center><img src="http://pictureposter.audiworld.com/66252/sub_collage_4.1.jpg"></center><p>The Concert HU is 2 x 20w to the fronts only.
The rears &amp; sub are powered by a 2 x 20w, 1 x 50w amp located inside the tupperware sub enclosure.
The fronts are 2 x 4" mids with 1" tweeters
The rears are 2 x 6.5" coaxials
The sub is a single cheapo door speaker mounted in a biscuit tin powered by a trimode amp the size of a cigarette pack.
No crossovers just 2 inline capacitors for the tweeters.
You can just about squeeze some 5.25" components in the font doors. There's loads of room behind the rears if you remove the polystyrene bolsters.
You will need adapter rings in order to fit any aftermarket speakers.
I produce a stealth sub enclosure for the A3 made from 18mm MDF housing a 6.5" JL Audio sub and driven by a 300wrms amp mounted behind the rear speaker panel. The sub fits in the same location as the OEM unit. It's a very impressive upgrade even using the OEM HU and speakers. You can pick up the rear pre-outs from the loom running to the OEM sub, so the only wiring needed is the power cable to the battery.

You must be describing the 2 door hatch A3, correct?

I should have been more specific. I'm asking about the 4 door hatch.

These will probably be the same as the fronts (if they have separate tweeters)