Picked up a 600 watt Motorcycle Tunes music system for JoJo's trike a few months ago. Been working on getting it installed over a few days recently.
The first go round of mounting the speakers where they suggest on the handlebars using P-clamps just didn't do it for me. Too "in your face" for my tastes.

I messed around a bit with how to mount them down near the triple tree area without hitting the tank at full lock. Here's what I came up with:
Took the upper windshield brackets off and took them to a fabricator friend of mine, who welded a 1 3/4 inch plate to the top of them and drilled out and welded a stud for upper mounting of the windshield instead of the bolt.
Drilled the plate for the speaker mounting stud (3/8") and mounted the speaker:


Got them angled correctly and tightened down:


Mounted the windshield back up and the clearance ended up great:



The system sounds great, clears the tank with many inches to spare, and the windshield directs the sound towards the rider. All and all worth the hassle of custom fabrication, and looks a TON better then handlebar mounting IMO.
Just wanted to show it off if anyone else is interested in mounting up external speakers on a Standard/Tourer.