Maybe I am nutz,(actually , no maybe about it [Big Grin] ) but I find Dacron to be louder than the lower stretch alternatives.
You aren't crazy...at least not for that.
There are lots of variables to consider. From just the string standpoint (leaving out bow design, release, arrow weight, etc.) the noise comes mainly from string vibration. This comes from elasticity, and polyester ("Dacron") has the most elasticity of any of the commercial string materials. The noise will definitely last longer because the string will vibrate longer.
Something I forgot to mention earlier is nock fit. If your nocks snap on the string tight, that will add noise also.
Worst case scenario, it could be the bow. Some bows, for whatever reason, just won't be made quiet--or as quiet as we want.