I had originally mounted the tweeters in the space from the factory speakers on the dash. I held them in place by bolting foam in the hole and the tweeter sat in the middle. However, due to the harsh Aussie sun, the foam warped a little and the tweeters moved down into the cavity enough to distort the sound.
The solution was to install a mounting plate and put the tweeters on them.
First step was to cut the plate itself. I used about 15mm MDF and traced a line around the original stock speaker. I then cut them out (them = 2, left and right sides) and tested that they fit alright.
You can also see that I’ve cut the hole for the speaker cable to go through. I used a hole cutting bit so that there was ample room for the cable to go through. The tweeter will sit on the whole so it won’t be visible anyway.
Next I jammed that sucker up in the spot where it was to sit to make sure it fit okay and to test how the speakers would sound and where I should position them. The only trick to this was that I had to pull most of the dash apart.
If you care, that meant the glove box removed, 2 air con pipes (on the passenger side), kick panels on both sides of the main console, under the steering wheel panel and fuse cover, and two air con pipes (on the drivers side). The whole back seat was full of bits of my dash!
Anyway, once the mounting plates were in place, I sat the tweeters on them to see how they would sound. I moved them around a bit as I played music and tried to work out the best way to face them.
When I found the perfect spot, I drew around them and then replaced the grill that covers them on the dash to make sure that they fit…. they didn’t. It turned out that the plate was too high, so I need to drop it a good inch or so.
After running through several scenarios in my mind, I decided the best thing, all considered, would be to have the plate suspended by long screws as the plate didn’t need to support a lot of weight and were pretty snug in there anyway. So the next step was to drill the holes for the screws.
I used the original speaker once again to make sure the holes were in the right place. Then I got the “tweeter keeper” and marked the holes to mount it on top. Then, I drilled.
Once the holes were drilled, the next step was to mount them. I should note that I did the two sides slightly differently. The left hand side (passenger side) I mounted the tweeter case in the middle of the mounting plate and pointed the tweeter at the car driver. The drivers side, I mounted at the rear of the plate and angled it slightly to the left (passenger side) of the driver. This was to try to get a sense of “front sound stage”.
I put the mount in once I had put the screws in to a certain depth and then screwed them into the plate. This meant that there was a gap of about an inch between the plate and the dash. It was also slightly at an angle facing forward due to the stuff under the dash, however this worked to my advantage.
Once the plate was in, I attached the case with 1 screw (drivers side) or two screws (passenger side).
Then once I tested that everything was fitting nice and solidly, I thread the wire through the holes and sat the tweeter on top of the case. Then since my tweeter has an adjustable top which swivvels to a degree, I positioned it as I had when I tested them earlier.
I gave them a final test once all hooked up to make sure the positioning was good. Then I adjusted as required and snapped the grill over the top again. This time they fit. 🙂
The system now sounds better than ever and I have properly positioned tweeters while still retaining the “Sleeper” style that I hold so dear.