[Technic]

Originally Posted by 949

i actually cant tell with those pics. the pics shows where the location is to install your harness, but weather the stock amp is severed from the whole new line, i cant tell nor can i tell if its between head unit to amp, or amp to speakers.

HK OEM amp has proprietary digital inputs -you cannot interface an aftermarket amp to the inputs of the OEM amp.

You should search for more details as this is outside the scope of the thread.

[949]

so that means that the harness will leave out the oem amp and use signals directly from the head unit into the loc.

[ckrieg]

Sorry to bump an old post, but wanted to say thanks for all of this info. That's awesome!

[Wowzers3888]

First, I want to say thanks for putting up this thread, it was hugely helpful. I too had trouble finding a good remote tap in and did not want to go through the dash (iDrive pin 13). I found what I thought was the red/white wire that the OP tapped into for the remote, but it would not activate the LC2i. I ended up tapping fuse 159 in the fuse holder in the trunk, but it stays active for 13 minutes after the car is turned off. I don't think this should cause too much drain (the amp not pushing any music), but I would to know if there is any more insight into exactly what wire is tapped from the harness bundle to get a good remote that does turn off with the car. Thanks!

[Allure]

Great write up. Will be doing this in my new M3

[carvwa]

Sweet! Much better than vamping speaker wires...

Speaking of, is there one of these for an 07 X3 w/nav but no CD changer?

[carvwa]

Best to obtain this stuff?

https://technicpnp.com/#homepage

Technic's website with Paypal check out.

[Soul_Glo]

Can anyone confirm: can I use any aftermarket amp or does it have to have balanced differential input? Thanks

[BMW_Sweden]

Originally Posted by jgentry

Due to the lack of information available for my specific audio setup, I figured it was my duty to record my findings for those of you wanting to add an aftermarket amp and sub to your system. I should mention that this forum has been very helpful but didn’t have one big DIY that I was looking for and it was always a little vague as to whether the content was for a stock, hifi or HK system or for what model of BMW it was targeted.

Here’s my setup:
2013 BMW 335i xDrive (F30) with the Harmon Kardon sound system

I had a 10” JL Audio (CS110RG-W3v3: Single 10W3v3 PowerWedge, Sealed, 2 Ω) subwoofer system that I had taken out of my previous car. The darn thing was just sitting in my garage looking at me, wondering why I wouldn’t install it in my F30. I finally got the courage after reading this post (http://www.f30post.com/forums/showthread.php?t=865182). I hit up Technic for details on the harness and line output converter or LOC (LC2i, specifically). Here was his reply on the subject (used with permission from Technic):

The F30 HK harness/LC2i to add an aftermarket amp to your OEM amp to power either a trunk sub or aftermarket underseat woofers is $145 shipped in the USA. Add $30 for outside the USA Shipping is 3-4 business days after payment. No shipping on weekends.

The LC2i active LOC is used in your particular OEM system due to the 35V+ peaks of the OEM amp woofer outputs. No remote turn on is possible with the OEM amp as all its outputs are Class D -no current signal sensing circuits can trigger with those.


I received the LC2i and harness within 1 week of ordering it from Technic. Below is a wiring diagram and picture of the harness (also used with permission from Technic):



First off, we need to remove pretty much every carpet panel from the trunk. The left-side carpet panel is connected to a 12V accessory plug, once the panel is initially free, you can unplug the two wires from the back of the accessory plug.



You will also need to remove the back seat panels next to each seat. To remove, simply fold down both back seats and then get a hand around the top of the cushion and pull. It should pop out pretty easily.



While taking off the carpet panels, you’ll see that they are all attached with black plastic “bolts”. I totally destroyed one of these before I could see how it works. There is a very thin disk that you can get a very flat screwdriver underneath. Once you pull out the middle part, the rest of the bolt comes out pretty easily. The picture below shows one of these “bolts” with the center portion popped out.



Also, you’ll need a size 40 (T-40) Torx bit to unscrew the tie-down hooks (the plastic caps pry off very easily).



The battery is located on the right side of the trunk (see those large red wires?).



The HK unit is located on the left side of the trunk. That large bundle of wires terminates in the plug that Technic’s harness will connect to.



The 20-pin connector has a sliding latch on it, simply slide it from left to right to detach. There are grooves in the plastic housing that will pull it away from the connections when you do the L-to-R motion.



The harness provided by Technic is a perfect match. Don’t worry, you don’t need to be forceful with the connector, it will only fit one way. Make sure the housing is slid all the way to the right, place the male and female together and then slide right-to-left and it should latch itself, repeat for the other side of the harness. I then tucked all the extra wire underneath, there’s plenty of space below. Here is where I want to make a note about the harness itself. Given the wiring diagram, you might be tempted to go tap into the wires without Technic’s harness. I should warn you, the wires down there are VERY TIGHT, as in no extra slack in the wires. I found this out when I was wiring in the remote-in for the amp and LOC (more on that later). The harness that Technic provides is very good quality, wired very neatly; I felt bad when I had to cut the high-level speaker output wires so as to extend them (I didn’t want to mount the LOC right next to the harness since there are some knobs on the LOC to tune the bass output and I wanted easy access). That white plug that is sticking out in the picture below connects to the high-level inputs on the LOC. I ran the newly-soldered wires around to the place where I mounted the LOC. Note that Technic’s harness allows for driving the OEM subs with an aftermarket amp (he even provides the plug for it). I decided to leave them connected to the OEM amp, I only wanted to add a subwoofer to my setup.



I ended up mounting the amp and LOC to the right rear seat because the amp wouldn’t really fit anywhere else. Also, I’m very paranoid about drilling into my trunk fearing that I’ll hit the gas tank or cut a wire. The seats seemed pretty safe. Note that they do have a metal backing so you’ll need to pre-drill all holes. I made sure the seat could still be latched with the amp in place (don’t mount it too high).



Now it’s time for running the power wires from the battery to the amp and LOC. I ended up buying two Car Toys install kits, one 8 Gauge for the amp and one 10 Gauge for the LOC. 8 Gauge was a little overkill for my amp but I want to leave room for upgrading the amp in the future, 10 Gauge is more than enough for the LOC. Both came with fuses that you want to connect as close as possible to the battery in case of a peak current event. I ended up connecting both directly to the positive battery terminal and then routed them back to where I mounted the amp and LOC. In the picture below, the blue wire is the 12V for the LOC and the see-through red cable is the wire providing 12V for the amp. Be careful here, I don’t know how much damage a 12V shock could do but I do recall a socket wrench having a pretty large notch taken out of it when I accidentally shorted the two terminals together on my first car in high school.



Sorry for not taking a picture of it but I connected the ground wire to a nut that was holding down the combo box in the middle of the trunk, right next to the fuses. Below is a picture of said fuses with the wiring in the background. Be sure to leave enough slack for the back seat to fold down and up without straining the wires.



Now the hard part (but easy for you now that I’ve found this). Technic pointed me to an M3 forum where they talked about where to find the remote-in wire that is used to tell the amp and LOC when to turn on/off. The wire wasn’t there, I searched all over the place and couldn’t find it. Not wanting to take the dash apart to get at the back of the iDrive (pin 13, by the way), I started plugging away at Google to see if anyone else solved this problem. Indeed they had, kind of. I found this forum entry (http://www.f30post.com/forums/showthread.php?t=729073) post 18 that talked about a little black wire (which wasn’t there on my system) but they also mentioned a red and white wire in post 20 which was. It is a little hard to see in the picture below (ignore the speaker wire, that is the wire I used to extend the high-level wires for the LOC) but it should be unmistakable once you find it. It is in the same big bundle of wires that includes the high-level output wires that the harness tapped into. Most of the wires are twisted pairs. Since the info on this wire was pretty vague, I decided to throw a voltmeter on it to be sure. It read 12V, score! However, I wasn’t sure if it ever turned off so I waited. And waited. And waited. Then I closed all of my doors and waited some more. Eventually the trunk light turned off and I tried again. Wha-La, 0V (well, 2V but it was dropping as I watched, close enough I hope, I’m guessing 2V is close enough to 0V to trip the relay in the amp and LOC). I ended up splicing into this wire and running this back up to the amp and LOC. As I mentioned before, the wires in this bundle are very tight. I had to tug a LOT to get enough slack to wire in the remote-in wire to the amp/LOC.



Finish up all remaining connections (i.e. RCA from LOC to amp). Now all you have to do is remember how to put the trunk panels back together. When installing the back seat cushions, be sure to line up the hooks on the cushion with the hook receivers mounted to the car. Once aligned, give it a firm jab and it should re-connect. The plastic bolts should go in in reverse order that they came out; outer housing first, then center pin.

Below is the finished product. The speaker itself looks a little clunky but I wanted the ability to remove it if I needed extra trunk space. Maybe I can change out the carpet on it to match the trunk.



Now on to tuning, reply below if you have any thoughts on this. There are spots to tune the LOC, the amp and, of course, the EQ on the iDrive interface itself. Any recommendations on how to get the best sound out of this? I’ve been told you want to tune the low-level signal since the gain on it is pretty low.

I wanted to again thank Technic for providing the harness and LOC as well as the wiring diagram. Please send him a PM if you want to order anything.

Hey
Do you have the pictures(especially diagram for hk) still?
They are not displayed here

Thanks

[Billfitz]

I doubt you'll get an answer, the OP hasn't posted in five years.

[jgentry]

OP still here, I no longer have the BMW but I still get notified of replies to this topic.

Not sure why the original images aren't coming through. Maybe my account got put in probation because I haven't been here in 5 years? When I went and looked for the original images everything started appearing again.

Here's the HK diagram specifically but you should be able to refresh this thread to see all of the pictures again.

Cheers!

[Billfitz]

They don't show up for me, and when I try to go direct to them this is the result:

The owner of www.f30post.com has configured their website improperly. To protect your information from being stolen, Firefox has not connected to this website.

[jgentry]

Wonder what that's about... I do remember having to click through some warning on Chrome.

[F30_ILLEST]

Will this be the same for the HIFI systems ? I want to add a 12 inch subwoofer to a 2013 bmw 328i f30. I have the lc2i and i want to know where and which color wires for the underseat woofers I will need to tap into. Where would it be the best to get the remote turn on and power for the lc2i and amp.

[Billfitz]

There are only two wires connecting to each under seat woofer, and you only have to tap one woofer because the low frequency content is summed to mono.

[F30_ILLEST]

Originally Posted by Billfitz

There are only two wires connecting to each under seat woofer, and you only have to tap one woofer because the low frequency content is summed to mono.

Do you know the color of the wires that run to the under seat woofers?

[Billfitz]

No clue. There should be a wiring diagram for the hi-fi system floating around here somewhere.

[F30_ILLEST]

I've been looking and I can't seem to find a wiring diagram. Does anyone know the wire colors that run from the HIFI amp to both underseat woofers ? Would appreciate a response.

[Kevin @ Integral Audio]

What year and model? They are generally Black-Red++(pin 4)/Black-Brown--(pin 3) for Left and Blue-Red++(pin 23)/Blue-Brown--(pin 22) for Right. The colors sometimes vary, but the pins do not. Careful because there are duplicate colors (USW same as mid/tweet for that channel), be sure to confirm (larger gauge are USW).

What do you intend to do with that signal? You realize that is an extremely eq'd output signal? Since you have the HIFI you have access to a flat (mostly) analog signal from HU to HIFI amp.

[F30_ILLEST]

Originally Posted by Kevin @ Integral Audio

What year and model? They are generally Black-Red++(pin 4)/Black-Brown--(pin 3) for Left and Blue-Red++(pin 23)/Blue-Brown--(pin 22) for Right. The colors sometimes vary, but the pins do not. Careful because there are duplicate colors (USW same as mid/tweet for that channel), be sure to confirm (larger gauge are USW).

What do you intend to do with that signal? You realize that is an extremely eq'd output signal? Since you have the HIFI you have access to a flat (mostly) analog signal from HU to HIFI amp.

Originally Posted by Kevin @ Integral Audio

What year and model? They are generally Black-Red++(pin 4)/Black-Brown--(pin 3) for Left and Blue-Red++(pin 23)/Blue-Brown--(pin 22) for Right. The colors sometimes vary, but the pins do not. Careful because there are duplicate colors (USW same as mid/tweet for that channel), be sure to confirm (larger gauge are USW).

What do you intend to do with that signal? You realize that is an extremely eq'd output signal? Since you have the HIFI you have access to a flat (mostly) analog signal from HU to HIFI amp.

I have a 2013 bmw 328i with the hifi system and I plan to add a subwoofer in the trunk. I read some post on here about getting signal from the amp in the back but no one has posted which color wires to tap into both USW. Thank you for your response!

[Billfitz]

You only need to tap one USW. You can see the color of the wires by exposing where one attaches to one of the woofers. Using a harness is a better idea. Tapping the wires to one of the woofers is a necessity outside the US for those with base radios that have no separate amp.

[mik]

Originally Posted by F30_ILLEST

I have a 2013 bmw 328i with the hifi system and I plan to add a subwoofer in the trunk. I read some post on here about getting signal from the amp in the back but no one has posted which color wires to tap into both USW. Thank you for your response!

I have a technic harness for hifi that I’ll sell for cheap, then you won’t have to cut any wires