Afrite

Hi,
I've replaced my old (after market) car radio with the Audi RNS-E navi system. The RNS-E has only a 2 channel built-in amp! But he has also 4 line in/line out pins so you can connect an external amp.
My car (audi A4 B6) came only with 2 front speakers (none bose system) but last year I've added 2 rear speakers (phoenix gold) my self.
My question is: how can I get sound from the rear speakers as wel. Now I have sound only from the front speakers
If I have to use an amp, what kind of amp do I have to use 2,4 or 5 channel? I don't have a subwoofer and I'm not planning to get one. All that I need is some good sound inside of the car and not outside of it!
Are there any small amps who don't need to be connected directly to the car Battery?
The other question is: How many speakers does an Audi A4 B6 have? Standard I had 2 front speakers but I hear sound comming from the center of the dashboard as wel and when I checked the cables there were only 4 wires for FL-FL+/FR-FR+? Is that a kind of subwoofer or what?

Please help!

USP

to a factory amplifier, which is located in the trunk behind the lining on the passenger side. This is for Non-Bose also. I know because I do not have bose yet have this amplifier in that location. If you want to power the other speakers, you'll have to locate this unit, find a wiring diagram for it and tap the signals from there rather than the rns-e itself.

If you want to add an amplifier you'll have to get power from the battery unless there is some other "safe" source with enough juice to sufficiently power it but even then, the battery is the best way to go.

Lastly, the B6 has a total of 10 speakers:
Center Channel, Midrange and tweeter in each door and 1 rear subwoofer.

Hope this helped.