HELP with mounting the sub to the cabinet question

[moves]

Here are some pics of how I did it. I screwed up the cut on the 3 inch baffle and needed to over hang one of the prongs as you can see in the first pic. That one is a 3 prong T nut instead of a 4 for that very reason. I had trouble getting through the 3 inches from one side so I had to turn it over and cut through the other side to get the circle out. It's not perfect but I think it will do. I set the epoxy and tomorrow it will be cured. Then I'll test fit the driver inside.

 

[Swerd]

You've already installed your T nuts, so I'm a bit late. But I have some comments anyway. In the past, I had terrible results with T nuts. It was probably due to ignorance and inexperience.

• I used a hand held drill to make the holes for each T nut shaft. In my hands, it was impossible to make 8 holes that were all parallel to each other. When I mounted the woofer and tried to drive in the bolts, it was impossible to completely drive in all the bolts. The last bolt never would go all the way in. How did you drill the holes for your T nuts? By drill press or by hand held drill?
  
  
• I not only had to drill the holes for the shaft of the T nut, but ended up drilling small holes for each of the T nut prongs. When I started, I had foolishly thought it would be easy to drive the T nuts in with a hammer. I think you already realize this was a bad idea.
  
  
• Because of my bad experience with T nuts, I now use hex drive threaded inserts for soft wood, such as made by E-Z LOK. In my hands, they are much easier to install correctly. But that might also be due to how carefully I now drill the holes. I still drill hand held, but I use self centering hinge drill bits.