It doesn't matter how good your speakers are unless you're driving them. The Polks are fine and very popular but need a good amp. I'm running a Kenwood deck, 300amp Rockford Fosgate amplifier and 4 Pioneer speakers with 4 tweeters.
Trust me, there no stock HD setup that comes close to this.....


WOW! What an Awesome set up on your VTX!! Man I'd love to hear it..but I don't think ya got enough speakers!

The 4 Polk 501s I got are only rated at 45 watts- 135 peak. What size amp you think I need? 100 watt?