I got one of these
https://www.amazon.com/dp/B087FWD6C4/ref=dp_iou_view_item?ie=UTF8&th=1I have the three knob version, with power/volume, bass, and treble. It's the size of a pack of playing cards, and I zip-tied it to the bottom of my dash. I have a pair of 4" speakers mounted in a $6 plastic ammo box from Northern Tool that is stuck up in the stock speaker location. It is Bluetooth or aux-in only, so I play it off my phone or iPod. It sounds decent, but I can't hear it well at speed. I intend to redo my exhaust soon and getting the glass pack muffler out from under my feet, and end of the pipe out to the back bumper, I'm hoping some of the noise in the cab will go away. I'm also considering making a wood speaker box since I think it would sound better than the plastic ammo box. If your truck is on the quieter side, this may work for you and not cost too much.
