I'm about to install new speakers in my front doors. I'm going to put Polk 4inchers in which have a square 4 bolt pattern and from the reader that crutchfield sent with the speakers the stock ones are a triangle 4 bolt pattern. Crutchfield said you have to build a bracket, has anyone done this before? If so how and what did you use? And yes i've seen that website that sells a premade one for like 20 eros but i don't feel like using those. This is for a 98 a4 2.8qm non bose

 

You could cut a peice of 1/4 inch wood to fit. Fasten it to the wood then the wood to the door.

 

Ply or particleboard? obviously hardwood would be too nice for this.

 

do a search someone on here used dynamat and gave the how to do it but i don't rember who

 

Plywood would be my choice or anything I found in the scrap isle of Home Depot/Menards etc..etc..

Sheet metal would work just the samebut thinner &easier to manipulate. I might spray the metal after I know its good to go with some kind of rubberized coating to rid any echo sound.

 

I used to have Polk DB400's (4 inchers) in my doors, and what i did wastake out the old oem speakers and using a dremel cutting tool, i cut out the speaker basket so that all i hadleftwas the round outer plastic piece that has the 3 stock mounting points on it. I then dropped my speaker in between the mounting posts and laid the plastic piece over the speaker and screwed it down to hold the speaker in place.

It worked perfectly for me, and there is plenty of clearance. Hope that helps