Audio Signal for External Amp

Hi,

I have had a spare amplifier and a subwoofer speaker in my garage now several years after selling my E46 where I had it installed. Now I decided to give it a try and put it in my X3.

I did some measurements today and it seems that I can fit the 10" subwoofer on the left side in the trunk where the panel can be removed. The amplifier I will put either under the trunk floor right behind the rear seat back rest or then on the right side where again there is that removable panel.

My question is what is the easiest way to grab the signal to the amplifier. Looking at the car it seems that getting to the factory amp is a bit tricky and requires that left side panel to be removed which at least in E46 was a pain to do and the X3 looks very similar.

Would it be easier to remove the driver's seat and take the signal from the woofer under the seat and route the cable under the door sills to the back? I have already added some cables from front to back so it is not that hard to do. How is the frequency going into those factory woofers? Is going all the way down as low as the signal contains without being filtered on the low end?

Thoughts? Those who have accessed the factory amp, how much did you have to tear apart to get access to it?

I guess this is the pin assignment for the factory amp. See attachment.

- p

I can help with this easily. Here is what you can use:

http://www.sonicelectronix.com/cat_i...s.html?from=20

Rather than pick one I linked you to the whole slew of them. I would go with the MTX. Attached is where I mounted my amps and where you can pick up the speaker connections to add the processor.

If you need more help go the DIY and if that doesn't help PM me.

EE

I would love to know too how to get to the factory amp!

THanks Evlengr for the tips. I decided to take the easy way and just plug and extra amp with a sub connected to it, with minimal efforts and pieces I had in my garage floating around.

I decided to take the signal for the external amp from the factory 'subwoofer' under the passenger seat. My amp can take in high level inputs, and also turns the amp on from those (the amplifier is DLS CA20). Then routed the signal cable under the right side door sills and under the rear seat to the trunk area. I placed the amplifier under the front trunk floor piece. The subwoofer I placed onto the left side right next to the factory amplifier where there is the piece with the net that can be removed.

It works ok and does the job that I expected. Took two hours to install in slow motion from start to finnish once I had the sub enclosure built. I will take some pictures later and post them here.

eeeallan: I can PM you some instructions. You need to remove quite a bit.

- p

Here are some pics.

I just removed the 2 bolts in the rear and 2 nuts in the front side of the passenger seat, then reclined it out of the way. That gives enough space to get to the speaker grille and remove it and get to the speaker connector. I unplugged and cut the speaker wires and joined another wire to them to get the signal for my amp.

The amp is now temporarily in place to do adjustments and see that it fits. I will mount it better for final installation and probably I redo the trunk floor piece to make the amp a bit visible.

Then I made two holders for the sub and mounted them to the car. The other is using the factory amp bolt and the other carrying the weight on another bolt lower.

The box, and pretty much everything else too, was made of what leftovers I had in my garage floating around. The sub is an old 10" I had in my 2002 E46 long time ago and the box is not really big enough for it but the space in the car did not really give many options unless use fiberglass or similar.

I also reused my XLR connectors and cable form the earlier installation. Unfortunately the cable was not long enough to mount the female connector to the enclosure directly like it is meant to be done. So now the connector is half way in the cable... I need to buy some cable and redo this piece when finalizing the amp mounting.

And there is a pic before the carpeting of the enclosure testing the fitment. And finally a pic with the sub in place.

To do are to finalize the amp mounting and customize the floor trim piece, the connector with a new longer cable as well as figure out how to cover the sub since the factory trim piece no longer fits there. I was thinking of taking a piece of 3mm plywood and a new trim out if it. I have not found good matching carpet anywhere yet.

There is nothing audiophile in this, no math in the box to tune frequencies, rather a quick use what you got installation to get some more boost to the <60 Hz area. It sounds nice, not boombastic but smooth low bass.

- p