Mazda 6 Forums banner

1 - 4 of 4 Posts

Rally Racer
3,507 Posts
Discussion Starter · #1 · (Edited)
[Begin Part 1]
This question has come up over the years and in wanting the addition to my 2004 wagon I decided to figure it out. For anyone who is interested the addition was well worth it. I do now have to tighten my rear-view mirror because the factory Bose sub-woofer shakes the thing like crazy making cars an utter blur behind me.

What is needed:
  • Factory Bose powered sub-woofer.Wagon and hatch have a spare tire mounted 100W, 0.5 Ω, 5.25 in Sub-Woofer.

  • Factory short-cord(4M81-13A576-BB) that attaches to the sub-woofer and vehicle installed wiring behind the left rear interior panel.

  • Mini blase-fuse tap "add-a-circuit" to trigger Bose amp.

  • Line Out Converter (LOC).I used the Kicker KISLOC2 because it had potentiometers to adjust gain (very important to get balance correct)
  • Factory Wiring Connector to scavenge wire and pin combos for plugging into factory wiring. (not necessary if splicing)
  • Some 18GA and 14GA wire, plus solder, heat shrink tubing and electrical tape.
What is in a non-Bose equipped vehicle (no Navi).
I have a May/2004 Mazda 6s wagon. This vehicle stereo required an L701 jumper to integrate with aftermarket components but otherwise is normal for the vintage.

The Bose parts missing are:
  • Wire loom (4M81-13A576-BB) from the left rear to the sub.
  • Wire loom from stereo (to passenger foot-well) to Bose amp (under seat)
  • Bose amp (under seat)
  • Bose head-unit
  • Bose sub-woofer
Everything else is there including fuse, relay, and body wiring (except short-cords listed above).

[End Part 1]

Rally Racer
3,507 Posts
Discussion Starter · #2 · (Edited)
[Begin Part 2]

A. Establish Signal To Sub-woofer

1. Remove the radio (explained elsewhere)
2. Tap the front speaker wires for your LOC.
Mazda 6 Audio Pinout Diagram non-Bose highlighted.jpg
3. Using 2 RCA cables strip the wires and use the center connection for the positive (+) that will run to the factory wires. The outer portion of the RCA will be grounded against the chassis.
I also installed a pair of Harrison Labs passive crossovers (50Hz) to clean thing up a bit. This will not cut that low because of the low impedance (0.5 ohm) but I am unwilling to spend $100+ on an active solution and it did help take the bass out of the mud.​
The RCA cables will take the signal from the LOC to the factory harness [X-10] located on the center tunnel behind where the ash tray is.​
This is a very large multi-wire connector and we will add 3 wires here. One ground wire (for the sub-amplifier) and two signal wires will be added.​
4. Add signal wires and ground to factory connector.
Bose factory signal wiring marked.jpg
In the above picture the Lt.Green/yellow wire has been added as a ground for the Bose 100w amp. This needs to be a 14GA wire and attached to the factory location behind the radio and immediately below the information display. The 10mm ground bolt is facing out and only visible from the threads. There will be another wire grounded there. Use a small eyelet attachment to integrate with it. Use this attachment for the negative (-) wire of the RCA cable that comes from the LOC.​
The other two wires pictured are brown and black/blue. These are not factory colors but have been added. They are attached to the positive (+) of the RCA cables from the LOC.​
If you are not adding factory pinned wires the wires can be spliced on the other side of the large white connector pictured above. The ground is next to the violet wire in the upper corner and will be the only vacant spot on that top row. The two signal wires are directly below and it does not matter if they are mixed.​
Black = ground from 100w amp​
Brown = signal to sub-woofer​
Black/Red = signal to sub-woofer​

B. Establish Power To Sub-woofer

Everything you need is already in the car from the factory with one exception, the "remote" or "trigger" wire. Normally this wire comes from the Bose head unit (radio) and tells the Bose relay in the engine compartment to turn on. The relay then allows a larger current travel down the wiring to the sub-woofer amplifier.​
The non-Bose radio has a pin for this position (seen in a pic above (#2) as blue/black) but there is no wire in the connector for it.​
Red dot in image above.​
The factory non-Bose will produce a 12v current when the ignition is in the [Accessory] or [On] position, regardless of whether the radio is turned on or not.​
This is NOT enough current to operate the relay so another source will be needed.​
1. Establish a accessory controlled "remote" circuit.
Add a circuit accessory on CIGAR 15A.jpg
I used a mini-blade "add-a-circuit" to the kick panel fuse box. the position marked as [CIGAR 15A] works perfectly. (This circuit powers my Integrated Fog DRL setup with LED's as well)​

2. Integrate into factory wiring with power.
The connector you want is up under the dashboard on the drivers side. The large black multi-wire connector [X-04] has the wire we want to use to trigger the relay to power the amp.
Bose relay trigger wire = blue/black
Bose Triger wire.jpg
If you want to cut and splice your "add-a-circuit" then do it near the circle pictured above.
If you want to add a pinned wire then do it from the exact opposite side of the connector.
Visual access is easily gained from the panel on the side of the dashboard where the door abuts. This makes adding a wire easy and voids splicing or tapping (but you need a factory pinned connector).
The spot you want is above pink/blue and below green/red (see arrow in pic).
That's it for power

[End Part 2]


Rally Racer
3,507 Posts
Discussion Starter · #3 · (Edited)
[Begin Part 3]
Install Sub-woofer

1. Remove hardware to gain access behind the left rear panel.

2. Attach the short cord wiring loom that you got when you salvaged your sub-woofer.

3. Install sub-woofer and adjust gains on the LOC. Don't forget to replace the hold down bolt to accommodate the taller setup.


To complete the setup I replaced all 4 door speakers with JBL GT786 5x7 / 6x8 2-Way GT7-Series Coaxial Car Audio Speakers and 2-pair of Metra 72-5600 Speaker Wire Adapters for Select Ford Vehicles for a truly plug-and-play setup.
JBL GT7-86 speaker.jpg


Panavise custom mount with a ProClip holder and a 3.5mm Bluetooth Stereo Car Audio interface USB AUX In Adapter with separate Qualcomm 3.0 fast charger
20200625_160707.jpg 20200713_205405.jpg 20200713_210247.jpg

I cannot believe how much of an improvement this was over my 16 year old factory speakers!
[End Part 3]

350 Posts
I don't have a 1st-gen 6 at present, but this is an awesome write-up! Thanks, DrFeelGood!
  • Like
Reactions: DrFeelGood
1 - 4 of 4 Posts