I have a CRX with a roll bar that goes through the rear speaker holes. The stock size is 6 inch, and I have found that 4 inch speakers would fit in there as long as there was an adapter to hold them. The material I was going to use to create the adapter is an 1/8 sheet of aluminum. It is relatively heavy, and what I had laying around. My thoughts were to create the adapter, then cut out un-needed areas to keep it lighter and not put too much stress on the stock interior. Kind of like a truss structure.

I am not an audio connoisseur, I am just trying to drown out other noises. So, absolute perfect audio quality isn't something I desire.

The Kenwood ~50 rms 180 peak speakers are amped with an alphine KTP-445U power pack.

Cliffs: I am curious if this an aluminum sheet and truss design is a good approach for an adapter, or if I am doing it all wrong.

 

If the aluminum is what you got in your garage...it can work just fine. I like using ABS black plastic for such things because it is easier to work with.

 

I am guessing maybe carbon fiber sheet would be better than AL, but is it better than ABS plastic?

 

My experience with carbon fiber tells me it isn't as easy to work with than ABS. It can work just fine though.

 

Is the truss structure a bad idea?

 

I'm confused. I was thinking the support bar was already there and you were making a smaller speaker fit in the speaker location with a fabricated speaker mount.

 

But.... I just ordered abs plastic like you suggested. So I am going to do the upper right hand style.

 

That's pretty much like I was thinking. Maybe even some thin strip of rubber in between the ABS and where it contacts the body to minimize rattle. Also....I like the adhesive foam for house exterior door insulation (so air doesn't leak into the house). You can cut strips and stategically place them between body and interior panels to reduce the rattles. I have stiff mounts and a K20 in my EG. It works great.

 

Well this is what I ended up with. Wish I went with thicker abs though.

 

Looks good