Gen IV Post-FL HU Upgrade - Keeping Stock Amp

Stereos, amps, phone kits, Navi...

Gen IV Post-FL HU Upgrade - Keeping Stock Amp

Postby Crampy » Wed Feb 01, 2017 9:29 pm

Foreword: Post is a WIP. I'll be filling in a few details and adding in some pretty pictures over the next week or so once I'm back on WiFi.

Non-Destructive Liberty Post-Facelift GEN4 McIntosh Aftermarket Head Unit swap, retaining stock McIntosh Amplifier and Speakers

Jargon

J101 - The round plug/socket (picture) that goes between the McIntosh Amplifier and the McIntosh Head Unit. As per gfennessey’s work, these carry the audio signals, some grounding, and the switch trigger signals to the amplifier.

RCA - Same as your old VCR / DVD player used, RCA refers to the type of plug/socket on the ends of a coaxial cable.

Male Plug / Female Socket - Gender refers to the centre poles/sockets.

Jumper leads - No not the 400A battery jump start leads. These ones are header jumper leads, and are often used in breadboarding or connecting up Arduino shields.

Identifiers
HU - Head Unit
FL - Front Left Channel,
FR - Front Right Channel,
FC - Dash Speaker (Front Centre Channel)
RL - Rear Left Channel,
RR - Rear Right Channel,
SW - Subwoofer Channel
TRIGGER - Remote Out / Amp Trigger cable from aftermarket HU (Usually blue)
GND - -ve Earth / Ground.

Preamble
This modification relied heavily on the work of gfennessey’s thread here, and extends it to the next logical step; a non-destructive and completely removable version of the 5.1ch J101 to 4.1ch RCA conversion.

Options
There are two parts of this project that can be modified.

Firstly, you can either wire in the front centre speaker as a crossover (Same as gfennessey’s Install, only puts out audio that’s the difference between Front Left and Front Right), or as a secondary subwoofer. Just bear in mind, should you choose the latter, you do run the risk of feeding too much power to the amp or speaker and resulting in distortion (Since the HU thinks it’s driving a subwoofer). Untested. Someone with actual audio experience might actually know more.

Secondly, you can either use jumper sockets on the in-dash J101 plug, or jumper pins in the under-seat amp’s J101 socket.

I personally have used both configs, and prefer the latter, as I found the jumper sockets I used often vibrated loose from the J101 socket (The pins in there are slightly smaller than PCB header pins - enough for male male pins to fit very snugly in J101 sockets, but jumper sockets work loose with road vibration.

Shopping Lists
Either option
  • 40-pack male to female jumper leads (Jaycar SKU: Price: )
  • At least one spade connector. If you don’t have one, Jaycar will for a few bucks.
  • Aerpro 2008 Forester FM Radio to standard FM Radio adapter (Autobarn)
  • Aerpro Subaru 14-pin to ISO Adapter (Autobarn)
  • Crimps
  • 2.5mmø 1:2 heat shrink
  • 6-pin Molex connector (Jaycar SKU: Price: )
  • 2-channel Ground Loop Isolator (Jaycar SKU: Price: )
  • Cable ties
    In-dash option-specific
  • 5 x Male RCA to screw terminal adaptor (Jaycar SKU: Price: )
  • 12-pin Molex connector (Jaycar SKU: Price: )
    Under-seat option-specific
  • 7 x Female RCA to screw terminal adaptor (Jaycar SKU: Price: )
  • EITHER:
    1x Component (5 cable - R+G+B+R+L) RCA male to male cable (Jaycar SKU: Price: ), and
    1x Video Only RCA male to male cable (Jaycar SKU: Price: )
  • OR:
    2x Composite (3-cable - Video+R+L) RCA male to male cable (Jaycar SKU: Price: )

Part 1A: J101-RCA Adapter Cable (In-Dash)
  1. Collect four each jumper leads of a selection of colours identifiable for each channel audio (FL, FR, FC, RL, RR, SUB), three GND- leads, as well as a fourth for TRIGGER-AMP
  2. Remove the plastic sheathing from over both ends of each cable by levering up the locking pin with a precision flat-blade screwdriver (1.5mm max width)
  3. Cut the male end off each of the 24 jumper leads, and strip the ends back
  4. Crimp on the stripped ends the Molex connectors so that there are two of each channel cable for both sides of the Molex plug/socket set.
    Code: Select all
    Example 12-pin Molex:
    +-----+-----+-----+-----+
    | FL+ | FL- | FR+ | FR- |
    +-----+-----+-----+-----+
    | SW+ | SW- | FC+ | FC- |
    +-----+-----+-----+-----+
    | RL+ | RL- | RL+ | RR- |
    +-----+-----+-----+-----+
  5. Heat-shrink the female ends of the jumper leads on one side - these are to be inserted into the J101 plug.
  6. On the side of the plug that was not covered with heat shrink, connect the following channels to the respective terminal/Male RCA Plug adapters as such:
    Code: Select all
    RCA Adapter Number
    | +-------------+--------------+--------------+
    V | RCA Channel | +ve Terminal | -ve Terminal |
      +-------------+--------------+--------------+
    1 | FL          | FL+, FC+     | FL-          |
      +-------------+--------------+--------------+
    2 | FR          | FR+          | FR-, FC-     |
      +-------------+--------------+--------------+
    3 | RL          | RL+          | RL-          |
      +-------------+--------------+--------------+
    4 | RR          | RR+          | RR-          |
      +-------------+--------------+--------------+
    5 | SW          | SW+          | SW-          |
      +-------------+--------------+--------------+
  7. Insert the female ends of the leads into the end of the J101 cable,
  8. Cut and strip the ends of the three GND- pins. and crimp together into one of the ports on the six-pin Molex plug, and connect the far side to both HU GND- and GND- from the Subaru 14-pin plug. (See Part 2 for example pinout)

Part 1B: J101-RCA Adapter Cable (Under-Seat)
  1. Collect two each jumper leads of a selection of colours identifiable for each channel audio; FL, FR, FC, RL, RR, SUB, as well as three jumper leads for earthing and one for amp trigger.
  2. Remove the plastic sheathing from over the female end of each cable by levering up the locking pin with a precision flat-blade screwdriver (1.5mm max width)
  3. Cut the female end off each of the 24 audio cables, and strip the ends back.
  4. Connect the following channels to the respective terminal/Female RCA plug adapters as such:
    Code: Select all
    RCA Adapter Number
    | +-------------+--------------+--------------+
    V | RCA Channel | +ve Terminal | -ve Terminal |
      +-------------+--------------+--------------+
    1 | FL          | FL+, FC+     | FL-          |
      +-------------+--------------+--------------+
    2 | FR          | FR+          | FR-, FC-     |
      +-------------+--------------+--------------+
    3 | RL          | RL+          | RL-          |
      +-------------+--------------+--------------+
    4 | RR          | RR+          | RR-          |
      +-------------+--------------+--------------+
    5 | SW          | SW+          | SW-          |
      +-------------+--------------+--------------+
    6 | TRIGGER-AMP | TRIG+        | GND-         | // Under-seat side Trigger/Earth RCA adapter
      +-------------+--------------+--------------+
    7 | TRIGGER-HU  | TRIG+        | GND-         | // In-dash side Trigger/Earth RCA adapter
      +-------------+--------------+--------------+
  5. Connect the five channel outputs and TRIGGER-AMP cables to the ends of the six RCA cables.
  6. Disassemble the centre console assembly, and run the six RCA cables under the carpet (if practical, otherwise, as long as it's under the seat rails, it'll be fine *thumbs up*
  7. Run the cables forward, around the transmission, ensuring it doesn't interfere with any of the gear linkages, and up into the
  8. Connect TRIGGER-HU to the far end of TRIGGER-AMP's cable. Add both TRIGGER-HU, TRIGGER-AMP and the Earth to ports on the 6-pin Molex (Example pinout in Section 2)

Part 2: Head Unit Power and Steering Wheel Control Module
  • After connecting earths from either Part 1A or Part 1B, insert the 14-pin Subaru plug into the generic Aerpro adapter. Check the pinouts (pictured), as you may need to re-pin some of the outputs to use certain functions; which can be done with some swearing and a really small precision flat-bladed screwdriver.
  • Connect Amp Trigger, Constant 12V+, Accessory Switched 12V+, Ground, and the steering wheel control lines (As per the wire colouring discovered by gfennessey. From here, if you have a Metra Access SWC module, you can connect that as required, using the power sources in this molex plug. On the HU side, connect up the HU's Constant 12V, Switched 12V, and the Remote Trigger lines to the appropriate positions on the 6-pin Molex plug.
  • Connect the ground-loop isolator lead to GND-, either here, or to another grounding point inside the dash.

    Code: Select all
    Example 6-pin Molex:
    +--------+----------+-------------+
    | GROUND | CONSTANT | ACC. SWITCH |
    +--------+----------+-------------+
    |  SWC+  |   SWC-   | AMP TRIGGER |
    +--------+----------+-------------+

Part 3: Connect up Audio, Ground and Trigger cables to the J101 Plug/Socket
  • Connect the audio jumper leads to the J101 plug/socket as such:
    Code: Select all
    Note: Left and rights may be mixed up here, happy to amend if that's the case. Check by "rolling" stereo bias from full bias to one corner to the next around the vehicle, or if you, too, like to live dangerously, by plugging each channel individually... I take no responsibility if you blow your speaker or amp by doing so ;)
    AMP = Trigger in this case.

          +-----+     +-----+
          | FL+ |     | FR+ |
    +-----+-----+     +-----+
    | SW+ | FL- |     | FR- |
    +-----+-----+-----+-----+
    | SW- | GND | GND | AMP |
    +-----+-----+-----+-----+
    | GND | RL- | FC- | RR- |
    +-----+-----+-----+-----+
          | RL+ | FC+ | RR+ |
          +-----+-----+-----+
And that should be it. Put your dash back together, sit back, and admire your handiwork. :)
--
Adam Cramp
North Brisneyland
Crampy
 
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