I've seen alot of people asking about how to make a custom bracket...and I was looking for answers as well. The best advice I could find was to either have a shop custom make a bracket or to cut one out of wood.
I did alot of running around trying to find parts and couldnt really find a good fit. So I took a look in our back garage and this is what I found.
Take out your tweeter and use it to draw up a diagram on a scrap piece of regular old house siding. It should look like this.
Find the proper diameter hole to cut for your particular tweeter, should be able to find a pdf install guide or in the specification sheet. Then get a hole saw to match the diameter and cut your hole. "Make sure when you cut the hole it is only as big as the threads...Ex: The tweeter shouldnt fit into the hole saw it should be only to the edge of the threads."
Grab your favorite cutting tool and cut out the new bracket.
Find the proper size drill bit to drill out the screw holes.
Im still in the process of this particular install so I don't have finished pictures...My components are still on order. Im getting the Alpine SPX-17 Pro's for my front and back.
So I got to the rear deck, and I realized that with the mach 460 system the rear deck tweeter cutouts were a little large...and there are no pre-drilled holes for mounting.
So what I decided to do was get a scrap piece of cardboard and push it onto the bolt you see to the far right. Then I layed in the trunk traced the cutout onto the cardboard.
I grabbed a straight ruler and made a few mods to the design after drawing it out...this way I can add bolts with washers to the oversized mounting holes you see in the above pictures.
I traced out two of these from the cardboard to a piece of siding and cut them out. The siding im using has a different color back...so I mirrored the cutout to account for that.
I don't have my tweeters yet...but I layed this unfinished bracket in the rear deck to give an idea of how it will be placed.
The bolt you saw in the previous pictures (on the right) will go through the far right hole in the bracket. I will need to make the brackets hole slightly larger to account for the bolt size...but it will make for a simple solution to bolt down that side. All I need now is to get a bolt and washer for the window side and drill one small hole for the seat side and I have a tweeter mounting solution for the rear deck.
This solution will allow me to avoid cutting through my factory deck carpeting.