I'll call you on that one. Depending on where you put them they might even gain you a few FPS. I have chronoed a lot of bows, string silencers if placed correctly will effect your speed very little. If you do lose speed I bet it won't be enough that a chrono would be accurate enough to detect.

If you want to bolt a peice of equipment to your bow that costs 10 times what decent silencers cost and probably isn't as quiet feel free.

Paul