[Niko ZV]

First of all I'd like to share credit where it's due: special shout out to Ruebarb, PKells, and Danallxt, all of whom were wonderful efforts in help and definitely did after I went through all that was provided. It was a team effort in troubleshooting and I'm glad and hope to pay this forward and help someone else in need in our community.

Below, I put together a nice subwoofer install for G42 owners. Glad to have the G42 and the stock option 676 speakers are pretty good for non Harmon Kardon, but I wanted more bass.

Equipment:
- Technic PNP harness for add a sub only since I have a separate LOC.
- Audio Control LC2i Pro
- JBL GT5-2402BR subwoofers
- Helix SPX1000 Competition Amp
- Speaker wires and spare similar gauge wires for the LOC (blue wires in the pictures).
- RCA cables
- Power and ground cables from the batter for the amp

1) Of course after you take out all the plastics, you'll see the RAM module on the left when facing the inside of the trunk. You unplug the OEM harness and from there I ran from the Technic PNP harness.
2) On the Technic harness there are two separate (red power 12+) and black ground wires (with a spare similar gauge blue wires as an extension I added) to the according labeled power and ground of the Audio Control LC2i Pro.
3) I then ran a different power cable from the battery to the amp (so that the loc has power from the harness wires and the amp has its own power from the battery), and a different cable to the ground of the car for the amp.
4) I put a blue wire for the remote out of the LOC to the remote in on the amp.
5) Here is where I had to look into our community members for help and they gladly did, and I hope this helps our community:

You should be wiring the small Technic harness into the speaker inputs on the LOC = the harness that has the red for power is for power on the LOC, black is ground, white with black stripe wire is left negative speaker input, white is left positive speaker input, grey with black stripe is right negative, grey is right positive = these are the speaker inputs for adding a sub, NOT THE TECHNIC LABELED ONES!

6) By now everything should work, so here is where I did amp and loc tuning. On my Helix Competion Amp Tuning: These are based off of research and my personal tastes:
- Phase to 0,
- Bass freq to about 60hz,
- Bass EQ to about 11 db,
- Gain level all the way down then adjust factory main volume to 2/3 of the max where you then go to the amp gain to adjust the level back up before it distorts,
- Play with LPF until hear only low frequency
- Then retune the Acubass on the LOC.

7) I also set the according triggers in the LOC from the manual, and the audio trigger for the Loc works and then sends signal form the remote out on the Loc to the remote in on the amp.

Helpful links:
- https://www.audiocontrol.com/downloa...ser-manual.pdf
- https://g20.bimmerpost.com/forums/sh....php?t=1802816
- https://www.audiocontrol.com/knowled...odes-lc2i-pro/

[Ruebarb]

I can't see everything in your pics, but start with one piece at a time.

The Audio Control LC2i Pro technic pnp was powered from the battery, so you know it has power, you just need it to turn it on.

They have a post on how to trigger the unit, it has 3 methods
https://www.audiocontrol.com/knowled...n-on-the-lc2i/

Also did you read the entire instructions for the LC2i?

I would guess that you should use a 12v trigger mode.

Once you get it working with a known trigger, then move on.

I would contact the technic pnp for guidance on thier wires.
I would guess that one of the short wires can be used as a 12v trigger, multi meter would be used determine that when the technic is powered.

Not sure if this helps

Not sure if this video is of any help

[Niko ZV]

Originally Posted by Ruebarb

I can't see everything in your pics, but start with one piece at a time.

The Audio Control LC2i Pro technic pnp was powered from the battery, so you know it has power, you just need it to turn it on.

They have a post on how to trigger the unit, it has 3 methods
https://www.audiocontrol.com/knowled...n-on-the-lc2i/

Also did you read the entire instructions for the LC2i?

I would guess that you should use a 12v trigger mode.

Once you get it working with a known trigger, then move on.

I would contact the technic pnp for guidance on thier wires.
I would guess that one of the short wires can be used as a 12v trigger, multi meter would be used determine that when the technic is powered.

Not sure if this helps

Not sure if this video is of any help

The video and link were worth the view. After taking another look at the LC2i manual and using the link you provided, the remote in could be the issue if I switch the 12v trigger mode to "remote in" but then the question would arise to which fuse do I connect it to in the fuse box? I know x3m guys with the Harmon kardon use the number 212 location fuse but, but it might be different for the g42 with 676 option speakers.
Yet, even when I have the trigger mode of the loc on audio or GTO, the loc still does not turn on for some reason. Maybe I need to hook it up to the fuse box and set the trigger to remote in? If yes, then is the wire from the remote out from the loc to the remote in on the amp is not needed? Are those the 12v trigger modes you suggested? And which short wire are you referring to? Would it be safe to run a wire to the remote out on the loc and then another to the remote in on the amp or is that not needed?

[Ruebarb]

Originally Posted by Nikolai Roskov

The video and link were worth the view. After taking another look at the LC2i manual and using the link you provided, the remote in could be the issue if I switch the 12v trigger mode to "remote in" but then the question would arise to which fuse do I connect it to in the fuse box? I know x3m guys with the Harmon kardon use the number 212 location fuse but, but it might be different for the g42 with 676 option speakers.
Yet, even when I have the trigger mode of the loc on audio or GTO, the loc still does not turn on for some reason. Maybe I need to hook it up to the fuse box and set the trigger to remote in? If yes, then is the wire from the remote out from the loc to the remote in on the amp is not needed? Are those the 12v trigger modes you suggested? And which short wire are you referring to? Would it be safe to run a wire to the remote out on the loc and then another to the remote in on the amp or is that not needed?

To test the 12v trigger on the LC2, just use a piece a wire to the battery, keep it simple.

This is the config you should be using, also see the pic, items in yellow for 12v trigger. Also double check your pos & ground, circled in red.

8. For +12V remote turn on the Trigger Mode switch must be set to
“Rmt In”. Connect the Remote In (Rmt In) terminal of the unit to a
remote turn-on switch. Alternately, use GTO™ Signal Sense or Audio
Sense to trigger the unit on without a remote wire.

Remote Input
This is the traditional way to turn on the LC2i PRO and
gives you more control of exactly when the unit will turn
on. Most common places to connect the remote input
are from the ignition of the vehicle, fuse box, or some
other 12V source (such as a cigarette lighter).

Once you have the above sorted then move to this.

If one of the short wires, see pic circled on the Technic provide a 12v signal when the stereo is on, then you don't need to tap a fuse. That will simply that part. But you will need to test with a multi meter which of the wires have power when the stereo is turned on, looks like 2 grey, 1 white, and 1 white with blue stripe, my guess this is the trigger for 12v.

[Niko ZV]

Originally Posted by Ruebarb

To test the 12v trigger on the LC2, just use a piece a wire to the battery, keep it simple.

This is the config you should be using, also see the pic, items in yellow for 12v trigger. Also double check your pos & ground, circled in red.

8. For +12V remote turn on the Trigger Mode switch must be set to
"Rmt In". Connect the Remote In (Rmt In) terminal of the unit to a
remote turn-on switch. Alternately, use GTO™ Signal Sense or Audio
Sense to trigger the unit on without a remote wire.

Remote Input
This is the traditional way to turn on the LC2i PRO and
gives you more control of exactly when the unit will turn
on. Most common places to connect the remote input
are from the ignition of the vehicle, fuse box, or some
other 12V source (such as a cigarette lighter).

Once you have the above sorted then move to this.

If one of the short wires, see pic circled on the Technic provide a 12v signal when the stereo is on, then you don't need to tap a fuse. That will simply that part. But you will need to test with a multi meter which of the wires have power when the stereo is turned on, looks like 2 grey, 1 white, and 1 white with blue stripe, my guess this is the trigger for 12v.

Still no bass from factory amps and white left speaker positive as well as negative wires have no volts even though all connections are good. While the non-used grey and white wires from the picture with the red circle all measure over 7 Volts when the Technic harness pnp is hooked up, I got the loc and amp to turn on with the audio trigger although it randomly shuts off for some reason after about thirty seconds. Main problem now is no factory bass and no subwoofer bass yet. Keeps shutting off by itself and subs get low power frequency when my hand is on the jbl subs but not bass or sound. Not sure if tuning the amp is another issue although I don't see why it would be once bass plays.

[Ruebarb]

Originally Posted by Nikolai Roskov

Still no bass from factory amps and white left speaker positive as well as negative wires have no volts even though all connections are good. While the non-used grey and white wires from the picture with the red circle all measure over 7 Volts when the Technic harness pnp is hooked up, I got the loc and amp to turn on with the audio trigger although it randomly shuts off for some reason after about thirty seconds. Main problem now is no factory bass and no subwoofer bass yet. Keeps shutting off by itself and subs get low power frequency when my hand is on the jbl subs but not bass or sound. Not sure if tuning the amp is another issue although I don't see why it would be once bass plays.

The loc specifies a 12v trigger, so you many need to tap a fuse with a fuse that powers on with the car for the 12v trigger.

I see you running the green and white wires into the speaker inputs. My understanding from the video, those are only for splicing the factory sub into your aftermarket amp. So you should not be using them. You should be wiring the small harness into the speaker inputs on the LOC.

Once you connect the 2 green and white harnesses, you should have the factory bass back.

See the attached, I believe it should solve the mystery of the small harness wires. Though I wouldn't power your larger LOC with the red & black, I would go to the battery as you did.

Also see this

https://g20.bimmerpost.com/forums/sh....php?t=1802816

[Ruebarb]

This is a tap location for 12v when the car is on. Check it with your meter.

[Niko ZV]

Originally Posted by Ruebarb

The loc specifies a 12v trigger, so you many need to tap a fuse with a fuse that powers on with the car for the 12v trigger.

I see you running the green and white wires into the speaker inputs. My understanding from the video, those are only for splicing the factory sub into your aftermarket amp. So you should not be using them. You should be wiring the small harness into the speaker inputs on the LOC.

Once you connect the 2 green and white harnesses, you should have the factory bass back.

See the attached, I believe it should solve the mystery of the small harness wires. Though I wouldn't power your larger LOC with the red & black, I would go to the battery as you did.

Also see this

https://g20.bimmerpost.com/forums/sh....php?t=1802816

This was key. Check your pm

[MPR]

To confirm, is the LOC able to turn on using the speaker inputs from the technicpnp harness, or did you need to tap into the fuse box?

Thanks

[Niko ZV]

Originally Posted by MPR

To confirm, is the LOC able to turn on using the speaker inputs from the technicpnp harness, or did you need to tap into the fuse box?

Thanks

No tap, put the LOC to GTO sense to turn in with head unit. Welcome.

[MPR]

Originally Posted by Nikolai Roskov

No tap, put the LOC to GTO sense to turn in with head unit. Welcome.

Is this for the LC2i or wavtech link2 LOC, or both?

[MPR]

Bueller
...
Bueller

[Niko ZV]

Originally Posted by MPR

Is this for the LC2i or wavtech link2 LOC, or both?

Lc2i pro

[MPR]

Can you post pics of your amp/LOC mounting locations?

[MPR]

Originally Posted by Ruebarb

This is a tap location for 12v when the car is on. Check it with your meter.

Is this confirmed? And this is engine running or just accessories on?

I'm trying to find a fuse that only gets 12v when the motor is running, as this is the only time I'd want my in sub amp to be powered.

Thanks

Edit: it looks like this doesn't even exist in the g42

[MPR]

Nikolai Roskov I'm getting pretty weak output from my 1000w amp/sub. Did you end up powering your LC2i directly from the battery, or from the +/- on the Technic PNP harness? The LC2i is turning on (red light comes on) wired to the Technic harness so its getting power, but maybe it's not strong enough? I tried adjusting the levels/crossover on the LC2i and amp but it's just not outputting what I'd expect.

[Ruebarb]

With the Technic harness plugged in, I'm missing the rear right speaker, bass only. I got an email into them, did you have anything like this? Thanks

[MPR]

Originally Posted by MPR

Nikolai Roskov I'm getting pretty weak output from my 1000w amp/sub. Did you end up powering your LC2i directly from the battery, or from the +/- on the Technic PNP harness? The LC2i is turning on (red light comes on) wired to the Technic harness so its getting power, but maybe it's not strong enough? I tried adjusting the levels/crossover on the LC2i and amp but it's just not outputting what I'd expect.

For those who may have the same issue, I learned from a discussion with technic PNP support that I had the harness plugged into the upper unit instead of the lower unit in the trunk. Once this was switched everything sounded perfectly.