I accepted that a
spacer is needed for the Polk speakers in the door so I spent the weekend doing a DIY spacer.
There were a few common materials people use, but I didn’t want to make a custom spacer out of
Medium-density fibreboard (MDF) or any type of wood because I didn’t want to chance it to absorb moisture, or soak in water or what not via weather, or car wash and have to go back in to fix it. I wanted to do some sort of plastic but I couldn’t really find a material that I liked. I also didn’t want to spend a ridiculous amount of money for pre-cut spacers that can be purchased on amazon or eBay or whatever either.
I ended up finding some
Elmer’s Foam craft board at the dollar store for $1.25 and it seemed like it was the perfect material. So I decided to pick up a sheet that was
20 x 30 x 3/16 inches and see if I can make spacers for $1.25.
Before I got started on the mini project, I decided to do a
very minor test of the material on:
1) How well the hardware screws would bite and hold onto the foam board and
2) How the material would do in cold temperatures like our great Canadian winters. So I put in a few screws from the supplied hardware by Polk through 2 layers of the foam board and threw it into the freezer overnight to see if the material would become brittle or crack in cold temperatures. Took out the test piece the following morning and it looked like it had passed the test as there were no cracks, and all the screws still bit onto the board. It held up very well in -18 degrees Celsius as per the temperature reading on my freezer... a very generous Canadian winter I'd say...
The first order of business was to make sure I was able to attach the
speaker to rubber gasket to plastic universal spacer (which isn’t universal) to Elmer’s Foam board to car door. I decided to trace out the old factory speakers which had the 3 mounting points onto a piece of card board, and put the stencil onto the foam board. I ended up cutting out 4 squares (2 squares per door) that were
7.5 x 7.5 inches for a "double layer" spacer, and then I took the not so universal plastic spacer to find out which position fits best on that stencil and cut out the middle with a utility knife.
With some clothes hangers and an empty cardboard box for mounting, I lined up the
speaker to rubber gasket to plastic not so universal spacer to 2 pieces of foam board and screwed them in all together with the supplied hardware by Polk. As the long screws were sticking out in the back, I cut 4 tabs of foam board to cover up the screws which will be eventually compressed onto the door to minimize paint damage and potentially metal on metal vibration noise.
Before mounting onto the door, I needed to trim off the bottom part slightly and around both corners to make sure I have enough room to put back the door panels. So far it works and the speaker hasn’t fallen out on me yet. There is a slight vibration noise while testing the speakers at a "high" volume with the panel off but it might be just the loose wiring and exposed items around the door. Then again, it's a Subaru, so almost everything makes a plastic vibration noise. There is plenty of window clearance as I can roll down both the passenger and driver side window all the way down without hitting the speaker.
Obviously it’s not the nicest spacer out there but for a $1.25 I’d say it is a successful DIY. If it all goes wrong in the future, well, I guess I’ll be making spacers with a different material.
