...in between the ashtray and the AC controls is a row of buttons...well, in my car i only have one button to the far left, dsc i think.

1) There is no amp pop in BMW. The audio all goes through a DSP before the amp so you don't actually interface with the AMP directly anyway.

2) Opus 150W. I don't know if this model is available anymore but I can recommend any of the Opus PSU's. Carnetix PSU's are also very nice.

3) I supplied the PSU directly from the battery with a seperate fused (15A) run of wire to the battery in the trunk. The 150W opus will draw up to 12A (It is also internally fused at 15A) so I did not feel comfortable attaching it to any existing circuit in the car. The shutdown controller in the OPUS needs a 12V source to tell it when the car is on or off, and I supplied this from the ACC power line (the one that goes on and of with the key) wiring harness at the front of the car via 18ga wire. the current draw is very small. I believe the actual BMW head unit is NOT powered via this wire but from a battery connection, so don't try to power anything major off of it.

4) The normal VEN4 use is to wire the speaker load wires to a headunit's speaker output. We are wiring backwards, feeding these into the AMP's input -- so yes connect the speaker load side to the wiring harness and the RCA jack side (which would be running to an amp in most circumstances) to your sound card.

4 again) Yes, I am powering my radar detector from the same harness but it is not relevant to the CarPC -- just a convenient place to get 12V that turns on and off with the car. Don't forget that you also have to attach the ACC/Ignition (whichever comes on with the key) back to the antenna / remote wire in the same harness though. This will make the amp power on with the car. (See the loop in the photo above)

Gork - I have to revive this discussion, as I do in fact get amp pop. Any reason why I would experience it given what you stated above? I have an HK system running headless. I read that Zebel had the same thing. Any ideas?

Yes; the amp is on the driver's side behind the trunk panel. Both the regular Alpine and HK use the same harness.

If you just want to use the factory amp w/ no headunit, the easiest way to do it is to attach to the factory stereo harness rather than trying to splice into the wires that feed the amp. Unlike aftermarket amps, the only plug on the amp is a ~40 wire connector that is going to be a real pain to tap into. You can do it by just buying a BMW harness from Best Buy or any car stereo shop. Hook the harness connector up to the outputs of a Peripheral Electronics SVEN4. Loop the 12V ignition wire to the 12V antenna wire (this is your amp turn on wire also) and you're all set to plug RCA audio into the SVEN4. Another user has suggested to me that you use a line driver to turn your stereo audio output from the PC into higher voltage RCA input for the SVEN4. This is recommended, but not absolutely necessary.

You are basically going to build yourself one of these except you will probably be using an SVEN4 rather than the VEN4 that I used (it is now discontinued):



The biggest advantage for using this method of attachment is that you do not have to cut any wires! It's just like plugging in an aftermarket headunit. In fact, aside from looping the iginition wire back to the amp turn on, this is how you wire aftermarket headunits in the E46 to the stock amps.