[wurz154]

First of all I apologize for my bad English since I am Italian and I will make some grammar mistakes.
There are several thread about how to install an amp... but I am not asking... I am posting pics and info on how to install an aftermarket amp and thought was better making a new thread.
I intalled an amp with a sub in my e91 with a professional 10 speakers active system.

1st picture shows the amplifier on the left side of the car with cables connected.

2nd pic shows the connector already open (there's a little tap to press to being able to open the connector; there will be two peaces one black one grey)...
The tiny black cable is the remote (it's not a normal remote because it does supply +12 when you open a door and it will disengage after 5 minutesish after releasing the key).
The twister pair "blueGreen +, BlueBrown -" is the Rear Right Channel.
The twisted pair "YellowRed+,YellowBrown-" is the Rear Left Channel.
As for making the connection you can use wire taps or make a cut on the insulator with a wire stripper, enlarge the cut with a lighter and wrap the new cable around it, carefull to not cut the wire itself, The second solution is the one I used.... very clean... pict #2 shows the whole cables connected. It won't take any space.

3rd pic shows the battery clamp where I connected the main +12 power cable.The battery is located on the right side

4th shows the circuit braker installed on the right side of the trunk.

5th shows the Aftermarket Amplifier Infinity 7520a running mono and installed under the trunk in the hidden compartment.

6th shows the subwoofer (MTX rt10-04) installed on the left side opening door where emergency kit is installed. A 9' cut required.

7th Overall clean trunk

8th my baby 320d touring, mystic blue, beige, poplar, panorama roof, electric seats, steptronic, professional audio, 160 wheels.

I forgot to show the ground, but straight fwd, the GND- is connected to the left ground connector where all the other cables are connected. (there is also one on the right)

Mission accomplished... I decided to install a subwoofer to listen to lower frequencies which the system is not able to do.
The sub perform well and fill the car with the bottom end of the listening spectrum without being noticed.

Hope info is helpfull..
Any question feel free to ask.