Results 1 to 10 of 10

Thread: hacking current headunit output

  1. #1
    Maximum Bitrate tundra2000's Avatar
    Join Date
    Mar 2006
    Location
    Houston, TX
    Posts
    551

    hacking current headunit output



    theres a pinout of what goes from the back of my HU to a factory built-in amp in my truck. ive found which wires are the 4 speakers, and ive located them upon taking my dash apart. question is, if i am goin to keep my HU, how can i install a switch (most likely 4p3t), that will switch between the HU's output and and output from an ipod or anything with an aux jack? can this be done or are these wires here not the right level or what...

  2. #2
    Para Laura thanatos106's Avatar
    Join Date
    Nov 2004
    Location
    Miami Beach,FL U.S.A
    Posts
    3,497
    At least in My X the the HU was pair with the factory AMP so No way to acomplish what you sugesting, in the other hand this was my aproach:

    Aux-in for OEM radio (nissan)

    You just have to locate the pins inside the HU.

    Thanatos.
    RexBruMet Skin for FrodoPlayer

    Nissan Aux-in MOD


    Quote Originally Posted by bgoodman
    We're an international forum, post in whatever langauge you like.

  3. #3
    Variable Bitrate
    Join Date
    Jun 2004
    Location
    Rochester
    Posts
    272
    Do you still have the factory head unit? Is the picture you posted a picture of the factory Toyota connector?
    If your headunit uses the 20Pin Toyota connector, then there is an adapter that will give you the line-level input to the factory amplifier. And you can possibly switch that if you like.

    http://www.audiowarehouse.peachhost...._PR70-8113.htm

    Peace.

  4. #4
    Maximum Bitrate tundra2000's Avatar
    Join Date
    Mar 2006
    Location
    Houston, TX
    Posts
    551
    Quote Originally Posted by walky_talky20
    Do you still have the factory head unit? Is the picture you posted a picture of the factory Toyota connector?
    If your headunit uses the 20Pin Toyota connector, then there is an adapter that will give you the line-level input to the factory amplifier. And you can possibly switch that if you like.

    http://www.audiowarehouse.peachhost...._PR70-8113.htm

    Peace.


    yeah thats looking good. its got the right color wires and everything, but how would i go about switching that with an aux input and the HU input and then direct it to the amp?

  5. #5
    Variable Bitrate
    Join Date
    Jun 2004
    Location
    Rochester
    Posts
    272
    I think a better way to go would be to use the CD-CHANGER input on the back of your head unit and get an AUX-IN adapter. This would be the cleanest and easiest way to go. I'm pretty sure your head unit has this input.

    If it does not, or you don't feel like buying the adapter it is possible by accessing the line-level wires before they get to the factory amp. Because you are still using the factory head unit, the harness adapter I mentioned earlier is not necessary. To accomplish this you will need some kind of switch. A 4PDT at minimum I think. This will require that all the grounds be connected together, but I think that will be acceptable in this case. Another option would be to use a pre-made audio switch box and perhaps soldering on some RCA jacks. That might be the better option. Anyway here is a diagram of each:

    Name:  2000TundraLineSwitch.JPG
Views: 813
Size:  32.5 KB



    Name:  2000TundraLineSwitchBox.JPG
Views: 739
Size:  24.4 KB

    Note: The wire colors used are not by any means standard or significant. They are only for telling the wires apart.

  6. #6
    Maximum Bitrate tundra2000's Avatar
    Join Date
    Mar 2006
    Location
    Houston, TX
    Posts
    551
    what about these wires?

    they just go unused and the front audio is just converted to back? will this not mess with the fade and stuff? i agree the switchbox is best, and the ipod into the switchbox is no problem, but then should we only use the front audio for the second input? it could be fine, but it just doesnt seem right

  7. #7
    Maximum Bitrate psyrex's Avatar
    Join Date
    Jun 2005
    Location
    Oakland, CA
    Posts
    536
    Your options probably are to split it so that front and rear play exactly the same thing or to spend lots on good hardware to covert it with something like Dolby ProLogic II or DTS Neo:6. These convert 2 channel to 5 or 6 channel sound, allowing you to use all your speakers well.

    -psyrex
    Gen 1: Pentium 3 1GHz - ATX - 2005
    Gen 2: Pentium M 1.6GHz - ITX - 2006
    Gen 3: Pentium M 2.0GHz - 5.25" SBC - 2007
    Gen 4: (coming soon: Core2 Duo - 3.5" SBC - 2009)
    ...it never ends

  8. #8
    Variable Bitrate
    Join Date
    Jun 2004
    Location
    Rochester
    Posts
    272
    Those wires which are left unused in the diagram are the rear line-level outputs. They are identical to the front line-level outputs (when the fader is at 0). It is acceptable to use only the front set of outputs in this situation. Also most audio switch boxes only offer two channels instead of four. Of course you will lose Fading capability with this hookup. If Fading is desired you will have to switch all four signals, either with your own switch(first diagram) or with a switch box that supports 4 or more channels. Perhaps you could use an A/V switch box and use the video connection(s) to switch the rear audio channels as long as the switch box is not doing any amplfication or other processing along the video signal path.

    The switching gets much simpler if Fade control is not important. You can even tie all the grounds together and use a switch instead of a switch box(shown below). I've adapted this diagram from another post. It has been changed to show integration with the factory components:

    Name:  2000TundraLineSwitch2.JPG
Views: 1336
Size:  73.3 KB

    Again, an easier way would be to get the AUX-IN adapter for the CD-CHANGER input on the back of your factory radio. It's a little expensive though.
    http://www.crutchfield.com/S-cWmrto7...asp?i=581DFTOY

  9. #9
    Maximum Bitrate tundra2000's Avatar
    Join Date
    Mar 2006
    Location
    Houston, TX
    Posts
    551
    the sound coming from the headunit to the amplifier (currently) is a low level signal. will this setup (the one above this post) still work? just switching between the low level signals from the HU and the sound coming from the ipod?

  10. #10
    Variable Bitrate
    Join Date
    Jun 2004
    Location
    Rochester
    Posts
    272
    Yes, it is for low-level, in fact I would not recommend it for high-level systems. One minor issue you might run into is volume control: while switched to "head unit" everything will work like normal (minus the fader feature). When you switch to "iPod" mode, the volume control on the head unit will be irrelevant. The volume will be controlled completely by the iPod. Because the iPod's output might not match the amplifier input perfectly you may have to add a resistor (if it is too sensitive) or a small signal amplifier (if you can't get enough volume). But you may not have any issues at all, the level will probably match just fine without a problem.

    If you forget the switching and buy the AUX-IN adapter for your head unit, the head-unit's volume control will control both. It is all up to you. The easy and expensive way: aux-in adapter for $60-$70 OR the harder but cheaper way: one switch and some wiring and soldering for $3-$5.

Similar Threads

  1. Replies: 1
    Last Post: 04-04-2006, 04:00 PM
  2. radio receipt headunit
    By Tijs67 in forum Car Audio
    Replies: 0
    Last Post: 07-22-2005, 08:05 AM
  3. Replies: 0
    Last Post: 06-14-2004, 11:36 PM
  4. Suggestions for current for a USB relay controller...
    By Zac in forum General Hardware Discussion
    Replies: 2
    Last Post: 05-28-2004, 12:52 AM
  5. How many volts can a sound card output?
    By kkhendricks in forum General Hardware Discussion
    Replies: 5
    Last Post: 01-16-2001, 12:36 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •