Why would you want to do this?
An external speaker for your radio is a great way to make it more usable. They generally deliver better and louder sound than the radio's own speaker. By putting the speaker behind your head you are directing the sound at you, making it easier to hear and less irritating to your passengers. This placement also puts the speaker up and out of the way.
You can see in the photo that my ham radio is mounted down on my transmission tunnel. While this puts the radio at arms length and makes it easy to see and operate, it faces the speaker away from me, making it difficult to hear at times.
Note, this instructable is for cars with removable headrests only.
What you need:
- External speaker. I got a 'Roadking' unit on amazon for $15 that works great.
- Piece of paper
- Thin plywood
Step 1: Make a Template
- Remove your headrest, usually by pressing the adjustment button and pulling up.
- Get a piece of paper and trace the two posts of your headrest on it.
- Fold the paper in half so the two post marks are on top of each other. Hold the paper up to a bright light, like a window, to see that they are matched up.
- Unfold the paper and mark how far back you need to mount the radio.
- Fold it in half again and draw a design. Straight lines are easier to cut than curves.
- Cut out your template
Step 2: Make the Mount
- Trace the template onto your plywood.
- Cut it out.
- Drill holes. I didn't had a big enough drill, so I drilled as big of holes as I could and made them bigger with my sandpaper.
- Clean up the edges with your sandpaper.
Step 3: Install the Mount
- Attach your external speaker to the mount.
- Slip the headrest posts into the holes in the mount.
- Install the headrest.
- Hook up the speaker to your radio, and set the radio to output to it.