The closer to the center of your string you add weight the more it will slow things down. This is why string silencers really don't slow a bow down much, they are pretty close to the limbs in most cases. Most new bows come with what you call speed nocks. Which are a few nocks that are shrink wrapped near the cam or cams. Just measure this distance and put them in the same spot when you change your string. The company has probably already done the homework on the best place to put them.

And more weight isn't always better. You can have too much of a good thing. If you already have speed nocks I would not bother with the speed balls. Probably will not gain anything, may even slow you down a little.

And the metal D loops will REALLY slow your bow down because they are pretty heavy and right in the middle of your string. Same thing as adding that amount of weight to your arrow. I think its funny when I see someone shooting altra light carbons and then shooting a metal nocking loop. Sort of counter productive in my opinion.

The peeps with the tubing really rob your speed as well.

Paul