I also found the speakers on my 2011 base v6 to be lacking. I ended up upgrading to the pioneer TS-D6803R speakers and the sound difference is amazing. So much clearer than stock, and should probably sound good for any type of music (although I mostly listen to rock and metal) TS-D6802R - 6" x 8" 2-Way Speaker | Pioneer Electronics USA
I'm still using the stock radio and amp as I didnt want to shell out the cash to get the adapter to install an aftermarket radio and am very happy with the results. You should be able to find them for a cheaper price on ebay. The only other thing you need is a wiring harness adapter so you don't have to solder the wires to the speakers.
2014 Mustang GT 6R80, Procharger Stage 2 D1SC, BBK 85mm TB, Boss IM, Sai Li fuel system. Circle D 3C, 1-7/8" Kooks Long Tubes w/Offroad X Pipe, Lethal Over-Axle Pipes, Corsa Quad Axle-Back, Eibach Pro System Plus, BMR K member, Shaftmasters DS, Forgestar CF-5 Wheels and Nitto NT05 tires. Lund Tuned
Lots of suspension goodies and some other stuff I can't remember.