I had the same system on my Road King and it was very loud riding around town. I could annoy people at will at any signal lol. My GF (who bought me the system) sat at a signal and told me later she could hear it loud and clean in her car next to me...with windows up. That said, you cannot hear it well at speeds over 55 or so. Wind noise and distortion just kills it. It is what it is, a small 30 watt two speaker system output to small 4" speakers. It's not possible to make this system loud enough given the design and size requirements. I used my front speakers, mounted them to my engine guard....put on saddlebag lid speakers from Hogtunes, with a Rockford Fosgate PBR300x4 amp, a JL Audio CL-RLC pre amp that is used for a volume control and a gizmo called an iStreamer to take the digital music output from the iPod, it will charge the iPod and it outputs it into RCA cables which goes to the pre-amp. With these FOUR speakers hooked up, i can absolutely blast some one out sitting at a signal (if i wanted to, i'm respectful and i turn the volume down most of the time sitting at a light)...still at speeds above 75, the wind noise gets ya. It's really hard to get quality sound on a motorcycle without a windshield or fairing.
Tim