Which rear speaker wires to tap into for LOC/amp install - rear speaker has 4 wires?

[ClearEyes]

This is wrong. There is a DSP within the head unit. Many threads on this with actual evidence.

OP, I did not open the dash to splice my wires, I spliced into the wires at the connections under the dash where the wires connect to the door above the kick panels.

The wires go from the head unit to a connector above the kick panel on both sides of the vehicle. Very easy access.

I am really interested in doing this as I would like to tap into the front speakers for the signal, where are these connections you speak of? Under the dash on the drivers side where the fuse box is? If you can tell me exactly where and what color wires to splice into, that would be extremely helpful or even a guide or thread you followed to find that wire. All the threads i looked at, and ive been researching for weeks now, say you have to take out the head unit but since I recently got my car and have CPO warranty, I have been hesitant to take out the head unit.

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[BrandonSmith]

If you swing open your front doors, you’ll see the black rubber boot between the door and the car frame that all the wiring passes through. Where that rubber boot meets the frame of the car, there is a connector (about 1” x 1.5”) on the inside of the car. These connectors are above the kick panels. Kick panels are the interior trim pieces next to the doors on the floor (the left-hand, driver side kick panel has the fuse label on it).

I will take a couple pictures for you on my lunch break. I removed the kick panel to gain easier access to the connector, since it is tucked away pretty well, and disconnected the connector. There is also wire loom (black plastic tubing) that covers the wiring, so I trimmed that back a little to give me easier access to the wiring. Then I added my 18-22 gauge wire taps (I used “t-taps”, but “vampire” style would make more sense).

All in all it took me 20 minutes to complete the wiring, taking my time.

 

[BrandonSmith]

This is the right side (passenger side in NA). The left side (NA driver side) is identical, although there may be a wire or two in the way due to the fuse box.

Here are the wiring diagrams. Don’t just go off color as you may see two or three wires that are the same color in the same connector. Note the location of the wire as well. For instance, FR+ is gray, #3 pin; when viewing the terminal side of the connector as shown in the diagram, it is the top right wire, next to the purple #2 FR-.

Be aware there are three other gray wires and one other purple wire. This isn’t a problem if you’re paying attention to the wire location.

 

[Redraider]

This is wrong. There is a DSP within the head unit. Many threads on this with actual evidence.

OP, I did not open the dash to splice my wires, I spliced into the wires at the connections under the dash where the wires connect to the door above the kick panels.

The wires go from the head unit to a connector above the kick panel on both sides of the vehicle. Very easy access.

Awesome, the service manual did not show a DSP anywhere. Thanks for correcting!!

 

[BrandonSmith]

Awesome, the service manual did not show a DSP anywhere. Thanks for correcting!!

It is built into the headunit, not a separate unit.

 

[Redraider]

It is built into the headunit, not a separate unit.

What seems strange to me is why did Honda put a DSP in the head unit and send the mid and tweeter frequencies over one wire? If I install a DSP, I'd send separate signals to each speaker to take advantage of the DSP functionality and optimize the sound from each speaker so you dont get tunneling. Unless they wiring from the head unit sends signals to each speaker and the electrical wiring diagram I looked up is not correct. That makes more sense if there is a DSP.

 

[bikejog]

What seems strange to me is why did Honda put a DSP in the head unit and send the mid and tweeter frequencies over one wire? If I install a DSP, I'd send separate signals to each speaker to take advantage of the DSP functionality and optimize the sound from each speaker so you dont get tunneling. Unless they wiring from the head unit sends signals to each speaker and the electrical wiring diagram I looked up is not correct. That makes more sense if there is a DSP.

Four less amp channels to put in the HU so cheaper.

 

[ClearEyes]

If you swing open your front doors, you’ll see the black rubber boot between the door and the car frame that all the wiring passes through. Where that rubber boot meets the frame of the car, there is a connector (about 1” x 1.5”) on the inside of the car. These connectors are above the kick panels. Kick panels are the interior trim pieces next to the doors on the floor (the left-hand, driver side kick panel has the fuse label on it).

I will take a couple pictures for you on my lunch break. I removed the kick panel to gain easier access to the connector, since it is tucked away pretty well, and disconnected the connector. There is also wire loom (black plastic tubing) that covers the wiring, so I trimmed that back a little to give me easier access to the wiring. Then I added my 18-22 gauge wire taps (I used “t-taps”, but “vampire” style would make more sense).

All in all it took me 20 minutes to complete the wiring, taking my time.

Thanks man, this is perfect. I was able to get everything hooked up and used t taps on the rear speakers and I did feel like the sub was a little weak, especially at low volume. I plan to tap into the front speakers tomorrow. I really appreciate you taking the time to take the video and show me, I had given up on trying to tap the front speakers because I didnt want to open up the dash.

One quick question, did you hook up both L&R wires to one front speaker or you ran wires from both speakers to your LOC? In my first car, a 2013 civic, I didnt know much about audio wiring and paid a shop $80 to install an amp & sub. When i took the set up apart since I got my newer civic, I noticed he wired both L&R positives together and the negatives together and spliced those to the +/- of one rear speaker. I also did that today because I felt it was easier. Is the sound a lot worse if you just hook up the LOC to one speaker?

 

[BrandonSmith]

My underseat sub has L and R inputs, so I used both L and R inputs. My Kicker LOC has L and R speaker inputs and L and R RCA outputs. I tapped both front speakers. I believe there is a difference in sound between stereo and mono input. I unplugged one of the rca and the sound was diminished. I suggest tapping both speakers.

 

[integra15]

I would definitely use the signal from the front speakers. Premium sound or not. I would not trust the rear outputs to be clean and unfiltered even with the stock in dash radio.

 

[ClearEyes]

My underseat sub has L and R inputs, so I used both L and R inputs. My Kicker LOC has L and R speaker inputs and L and R RCA outputs. I tapped both front speakers. I believe there is a difference in sound between stereo and mono input. I unplugged one of the rca and the sound was diminished. I suggest tapping both speakers.

Did you just run some really long extra wires from the LOC to both speakers at the doors? My amp also has L/R RCA inputs but I had previously just hooked up the LOC to one speaker and ran both RCAs to my amp. Do you think remote wire would work? As thats basically the only small extra wire I have at this time. I think its 18awg wire but it seems the speaker wire is like 18-22 wire.

 

[BrandonSmith]

Did you just run some really long extra wires from the LOC to both speakers at the doors? My amp also has L/R RCA inputs but I had previously just hooked up the LOC to one speaker and ran both RCAs to my amp. Do you think remote wire would work? As thats basically the only small extra wire I have at this time. I think its 18awg wire but it seems the speaker wire is like 18-22 wire.

I actually mounted my LOC in the passenger side kick panel. 18ga wire will work fine for tapping the factory speakers (since that is what factory is using anyhow.

 

[ClearEyes]

Quick update: I finally got the time and used @BrandonSmith 's guide and tapped into the front speakers at the doors. Extremely easy install, took me about 30 mins to get to the harness, tap into speakers with LOC, and route the RCA cables to my amp in the back. It made a drastic difference, where before I felt the sub wasnt very loud at all and now its actually TOO strong where I had to install a punch control knob and turn it down. Thanks again for the video and instructions Brandon,.

 

[Dalestuff]

I'm just now reading this thread. I too am trying to install a sub in the trunk of my 2019 Civic sport. I too wondered why there are four wires. One thing I did notice after I cut all four wires to the speaker is this,
there is only a signal coming across one pair not both. So I'm curious as to if the pair that has no signal is actually feeding the Tweeter?

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