05-12-2014, 04:19 PM
I have used wooden tongue depressors (popsicle sticks) to reinforce grill backing. I used regular old wood glue. You should be able to buy a bag of the wooden sticks for a couple of bucks. They are easy to trim. Smear some glue on the stick and press it on the cardboard. Just be sure the new wood doesn't interfere with speaker installation.
The artist formerly known as Puhpow! 8)
