Maybe someone out there can answer my question. I have a Diamond Triumph 67# @ 28" and I'm getting 260fps with my current 450 grain arrows. I also have 540 grain arrows that I get 243fps with. That makes about 2 ftlbs of kinetic energy difference so I'm not too worried about that. My question is if there is a point of diminishing return in the weight of an arrow effecting the noise of the bow. When I shoot both arrows no one notices a difference in sound between the 2. I would have thought that 90 grains would make a difference but I can't tell myself either. What gives?