kevinnpcb's way is similar to my way. I just used a piece of thin sheet metal laying around and folded a complete bracket and sandwiched between radio and fairing bracket (drill somewhat oversized holes so you can position the bracket up/down in/out).
pro on my bracket is it will hold any amp - within reason - with velcro

 

nice idea.. think I might use that next time myself.. thanks for sharing guys..

 

I wished I oversized the holes. It would have made starting the bolts much easier. I drilled them only a little larger than the bolt threads, I had to get everything lined up just right before the bolts would start without trying to cross thread.

 

As i need one more post lol to get to the next stage of "Audio Crush" , I dug up some pictures of the bracket... no pics off the bike but you will see what I mean...

 

guess one more post needed LOL...
pics show SS amp, got RZ on it now, fits as well...

 

nice job there Road Master..