Install Subwoofers

This will guide you through the process of Install a Subwoofer in a 2000 VW Jetta GLS to an aftermarket CD player (or stock) in your car.

Steps

  1. The most cost effective first step is to buy an amplifier wiring kit off of an internet auction site, etc. This will come with a huge power wire, a short ground wire, a remote wire, and many times an inline fuse and various connectors to help keep the install organized and looking clean. Some stereo shops have huge spools of wire available by the foot. This is another cost effective alternative to buying a wiring kit, if you know the dimensions of your car.
  2. Run the 12v power wire (usually the longest wire in the kit, mostly red, typically ranges from 8 gauge to 0 gauge) from the battery through the firewall and then to the amp. You can find a hole somewhere in the bottom right of the firewall. Don't connect the power wire to the battery or the amp just yet.
  3. Find a solid metal ground somewhere near the amplifier. You'll need to stay within {{safesubst:#invoke:convert|convert}} of the amplifier to maintain the best ground connection. A way you can do this is pull up the carpet and scrape the metal until it is bare metal with no paint left on it. If the amplifier is to be mounted in the trunk, many times bolts from the suspension can be found directly above one of the rear wheels. These suspension components usually bolt directly to the frame, making them an ideal grounding point.
  4. Pull the aftermarket CD player out of the dash. There is a blue wire with a white stripe hanging out of the back of the deck known as the remote wire. The remote wire is a simple 12v signal that the cd player outputs to tell the amplifier to turn on.
  5. Take your remote wire that came in your amp kit and splice/solder it onto that blue and white-striped wire and run it through the dash and then along the door jam.
  6. While you have the CD player removed, plug the RCA white and red plugs into the back of the deck where it says "Subwoofer Output." If your cd player does not have a "Subwoofer Output", or if you are using a stock cd player, you will need a device called an inline converter. It's a small box that has 4 input wires and the 2 necessary RCA output that will run to the amplifier. It takes the high level speaker voltage and drops it to a low level signal the amplifier can process. The 4 input wires can be connected to the rear speakers (+ and - for left and right).
  7. Run all the wires straight back to the amplifier.you should run the power and remote control down the right as factory speaker wires run down the left due to fire risks if the power cable shorts out and you have your speaker cables down the same side it will blow your head deck (cd player). RCA cables should be run down the center of the car as RCA cables can pick up sounds from wire looms and also air con vents power wires.
  8. Use Speaker Wire to connect sub-woofers to amplifier. Gauge isn't extremely important here, as long as the wire is copper, the resistance-per-foot is in the mili-ohm range, meaning there will be minuscule, if any, voltage drop across the wire.
  9. Hopefully by now you have a subwoofer box/enclosure. There are many different types of enclosures (sealed, vented, bandpass, infinite baffle, etc.). There are numerous articles explaining the pros and cons of each type of enclosure, far too many to list in this article. If you really want the best response possible, your subwoofer manual will list the ideal enclosure volume for each type of enclosure. If you don't want to go through all of the volume calculations, just buy a box slightly bigger, and stuff it with pillow stuffing from walmart until the subs respond the way you want them to.
  10. Be sure to know the impedance of the subwoofer(s) you are using and try to match the amplifier's impedance accordingly. For example, if you have an amp that is 500w @ 4 ohms, and 1000w @ 2 ohms, you'll want to try to run your speakers at 2 ohms. Two 4 ohm subs can be wired in parallel to achieve this. If you're new to the impedance calculations, many amplifiers will have specific wiring diagrams in their manuals to assist.
  11. Put a fuse into 12v wire in the engine bay no more than 0.5m away from battery. If your amp kit came with an "inline fuse holder", you'll want to find a nice location to mount it in your engine bay. Once it's secure, cut a length of the power wire to reach the fuse, and connect it to one side of the fuse holder. The other side (the side you just cut) is stripped and connected to the other side of the fuse holder.
  12. Connect the power wire to your battery. There's nice ring connectors and even new battery terminals you can buy (and sometimes come with the amp kit), that make the battery connection much more solid, and looks better too.
  13. Lastly, connect the battery cable to the amplifier. Then under the hood clamp the wire down to the battery. A word of warning, sometimes you'll see a nice big spark the first time you touch the power wire to the battery. Don't worry about it! This is the amplifier charging the huge capacitors contained inside.
  14. Do not turn up the volume or gain too high or you may produce clipping in the subwoofers. This is where the output of the amplifier peaks and stays there for a split-second. This is bad for the subwoofer because it holds the cone (the big circle part!) in it's fully extended or fully compressed state for the duration of the clip. Not only are you not producing a single decibel of sound during this microsecond, but you're also working the voice coil very hard and damaging it. A good rule for beginners is to play a nice loud song of your genre at your cd players 3/4 volume setting. Now, with the gain at zero, turn it up until it's obvious that it isn't getting any louder. The gain knob isn't a "volume" knob by any means. A gain knob should usually never be at it's full position.



Tips

  • Make sure you do not put the fuse in until the end.
  • Connecting subwoofers to a stock system may include a couple of extra steps, like the inline converter explained in the "Steps" section, or attaching the remote wire to an ignition activated fuse in the fuse panel.
  • Look into "sound deadening" foam or spray to alleviate the rattles that may appear in your interior trim and rear trunk panels after the installation.
  • A good quality used subwoofer can last for years, but unless you REALLY know what you are doing, a nice NEW amp may be the best choice. For simplicity, get a "mono" type amp since subwoofers (especially one woofer) are not technically stereo.
  • Make sure you wrap all your wire connections with electric tape to reduce wires connecting to other metal parts and shorting.
  • If you blow your fuse when you try to turn the amp on, this is almost always a bad ground connection. Disconnect it, use a wire brush or cleaning agent on the ground connection area and try again. Otherwise, find a new ground.
  • Mount your amp off of the floor of your trunk so that if something leaks or spills, you do not have to replace it due to damage.
  • Make sure that all wires run neatly to the amp to prevent a re-do.
  • Make sure you check your fuse box to see if there are not any burnt fuses if there are burnt fuses you might have problems with the amplifier like it won't turn on connected to the subwoofers. This can be any device that only works when the ignition is turned on (a good example would be the windshield wipers).

Warnings

  • Consult your mechanic or local (authorized) auto electrician in case your make or model has special needs or risks (software installations, or risks from improperly disconnecting the battery). This is especially true with newer cars (domestic and foreign).
  • Disconnect the battery before working on any electrical parts of your car that involve bare wires or connectors; a mis-connected lead could result in a damaged relay, blown fuses, or damage to your computer, which could be quite costly to repair.
  • Be careful not to give yourself an electric shock because it is quite painful.

Things You'll Need

  • wire strippers
  • 12 gauge or bigger wire (10 gauge, 8 gauge, etc)
  • large power cord (ideally red)
  • inserts for fuses (for a small or moderate system 20-30 amps usually will do it)
  • wire crimpers
  • tin sheers or wire cutters
  • electrical tape
  • zip ties
  • male and female butt connectors
  • forked wire connectors
  • crimp connectors (tube type, shrink wrap type if you really want a pro look to it)
  • multi meter (just to make sure you have the right wires)
  • flashlight
  • wiring diagram for your aftermarket stereo or stock setup
  • screwdriver (phillips and flat)
  • knife
  • screws, washers, nuts, and possibly a little weather stripping (for padding) for the installation for the amp.
  • Wire tester (usually has a little light at the end of it.)
  • small metal file (to get paint off of floor for ground wire)
  • possibly electric drill (for mounting amp, drilling holes for wires, or to mount sub enclosure [which is also a good idea])

Related Articles