I'd like to install my old Alpine MRP-M350 mono amp and DVC 12" sub in my E39 540i with DSP. Unfortunately I'm a bit clueless on where to start other than where to tap the power and ground. I've listed the pinout detail below as reference.

1) My first question - pretty elementary - assuming that I use the large 15 pin plug for all my speaker outputs and a switched power lead, how are the pins numbered on the connector? In other words, the connector has 8 pins on one side and 7 on the other - how are the pins numbered?

2) Second question - for speaker outputs to tap into, I've read that all the sub outputs are the same regardless of whether you use 1-4 - is this true? It's also been recommended in other posts I've seen that you use the speaker leve inputs on the amp to drive the signal. This is fine as my Alpine has speaker level inputs. What confuses me though is that it has +/- inputs for two channels although it's a monoblock amp - do I just need to run a signal to channel 1 and not worry about channel 2?

3) Third question and last question - is pin 4 (Radio on/antenna signal) in the list below a good one to tap for the switched power source?

PIN CONNECTION
1- Sub 1 +
2- Sub 2 +
3- LH Rear loudspeaker + (Touring LH rear speaker ground)
4- Radio on/antenna signal
5- RH rear loudspeaker + (Touring RH rear +)
6- Sub 4 -
7- Sub 3 -
8- Terminal 30 connects to Fuse 56
9- Sub 1 -
10- Sub 2 -
11- Touring LH rear +
12- Touring RH rear -
13- Sub 4 +
14- Sub 3 +
15- Terminal 31 connects to Ground Point

Sorry for all the questions - I've read a ton of posts, but unfortunately most of them cater more towards people who are either familiar with stereo installing or for non-DSP systems.

Thanks!
Sung

I just completed this project last week so I am very familiar with what you are asking. Below are my responses.

1)If you look very closely at the plug, you will see the numbers.
2)I would not use the Alpine speaker level inputs. The DSP Amp puts out a lot of power and it may damage the Alpine. Get a Soundgate LOCHVA or LOCX and use the low level inputs on the amp.
3)Yes.

Good Luck.

awesome - good stuff, thanks for the tip on the plug, feel like a dumbass now!

In terms of a good LOCX - did you use something like this one?: http://www.soundgate.com/index.php?request=product.details&categoryid=208&productid=475&usereferrer=1

Wheresthewagons just posted on my other thread on this in the 5er specific forum with a slightly different install method - I'm assuming this would not require a LOC? What would be the pros/cons of using a LOC and running the speaker signal to the line-level on my amp as opposed to just tapping off the speakers and going into my speaker-level inputs?

I just did an amp and sub install in a 540 touring. It was the easiest sub install i have ever done.

Use the speaker level inputs for your amp. The reason your amp has 2 inputs even though it is mono, is because car stereo are stereo (left and right channel). The bass level is not equal in both channels so the amp takes the signal from both and amplifies it to one speaker. You should use both.

There should be four wires on the plug into your dsp subs. It is two sets of pos and neg. Those are the wires you will use to get the speaker level signal for your amp. Just us one for the right channel and one for the left. It doesnt matter which goes where.

The radio antenna wire you are talking about should be SOLID white. It is the only all white wire on the plug. Tap into that for your amp on power.

I think that solves your issues... let me know if you have anymore questions.

I would be careful. Your Alpine may not be able to handle the speaker level inputs. I would play it safe and buy a LOC. The LOCX should work well.

I ended up using a PAC SNI-35 adjustable 2-channel LOC. Still trying to figure out the best way to tune the system though.

The setup definitely bumps but I want to make sure the sub has enough headroom to not distort at the highest volume I listen to. From other posts, it sounds like the best way to do so would be to simply turn up the headunit until it's clipping, then turn it back to just below that, and then slowly raise the gain on the sub amp until it either meets the amount of bass you want, or start clipping as well.

This seems pretty straightforward, but one thing I'm confused about is how I should set the level on the LOC before sending the signal to the sub amp. What's a good rule of thumb on setting the level on the LOC?

Start with the headunit and work your way back.