Four rubber string silencers will more than likely rob lots of energy from your bow that would otherwise go into the arrow. If you want to see how much, bare-shaft tune with and without the silencers. You might be amazed. The worst case in my experience was a fellow who had put several sets of rubber spiders on his string, and when we removed them his spine went up more than 20#. The bow was very quiet, but he could have been shooting 20# less draw weight and gotten the same performance! I use only lightweight silencers, as close to the tips as possible. The closer to the center of the string they are, the more effect the weight has on the performance of the bow.
As KentuckyTJ pointed out, there are better ways to quieten a bow than heaping on string silencers.